Adding upstream version 6.6.15.upstream/6.6.15

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

104 files changed, 52765 insertions, 0 deletions

diff --git a/sound/core/Kconfig b/sound/core/Kconfig
new file mode 100644
index 0000000000..e41818e59a
--- /dev/null
+++ b/sound/core/Kconfig
@@ -0,0 +1,250 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# ALSA soundcard-configuration
+config SND_TIMER
+	tristate
+
+config SND_PCM
+	tristate
+	select SND_TIMER if SND_PCM_TIMER
+
+config SND_PCM_ELD
+	bool
+
+config SND_PCM_IEC958
+	bool
+
+config SND_DMAENGINE_PCM
+	tristate
+
+config SND_HWDEP
+	tristate
+
+config SND_SEQ_DEVICE
+	tristate
+
+config SND_RAWMIDI
+	tristate
+	select SND_SEQ_DEVICE if SND_SEQUENCER != n
+
+config SND_UMP
+	tristate
+	select SND_RAWMIDI
+
+config SND_UMP_LEGACY_RAWMIDI
+	bool "Legacy raw MIDI support for UMP streams"
+	depends on SND_UMP
+	help
+	  This option enables the legacy raw MIDI support for UMP streams.
+	  When this option is set, an additional rawmidi device for the
+	  legacy MIDI 1.0 byte streams is created for each UMP Endpoint.
+	  The device contains 16 substreams corresponding to UMP groups.
+
+config SND_COMPRESS_OFFLOAD
+	tristate
+
+config SND_JACK
+	bool
+
+# enable input device support in jack layer
+config SND_JACK_INPUT_DEV
+	bool
+	depends on SND_JACK
+	default y if INPUT=y || INPUT=SND
+
+config SND_OSSEMUL
+	bool "Enable OSS Emulation"
+	select SOUND_OSS_CORE
+	help
+	  This option enables the build of OSS emulation layer.
+
+config SND_MIXER_OSS
+	tristate "OSS Mixer API"
+	depends on SND_OSSEMUL
+	help
+	  To enable OSS mixer API emulation (/dev/mixer*), say Y here
+	  and read <file:Documentation/sound/designs/oss-emulation.rst>.
+
+	  Many programs still use the OSS API, so say Y.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-mixer-oss.
+
+config SND_PCM_OSS
+	tristate "OSS PCM (digital audio) API"
+	depends on SND_OSSEMUL
+	select SND_PCM
+	help
+	  To enable OSS digital audio (PCM) emulation (/dev/dsp*), say Y
+	  here and read <file:Documentation/sound/designs/oss-emulation.rst>.
+
+	  Many programs still use the OSS API, so say Y.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-pcm-oss.
+
+config SND_PCM_OSS_PLUGINS
+	bool "OSS PCM (digital audio) API - Include plugin system"
+	depends on SND_PCM_OSS
+	default y
+	help
+	  If you disable this option, the ALSA's OSS PCM API will not
+	  support conversion of channels, formats and rates. It will
+	  behave like most of new OSS/Free drivers in 2.4/2.6 kernels.
+
+config SND_PCM_TIMER
+	bool "PCM timer interface" if EXPERT
+	default y
+	help
+	  If you disable this option, pcm timer will be unavailable, so
+	  those stubs that use pcm timer (e.g. dmix, dsnoop & co) may work
+	  incorrectly.
+
+	  For some embedded devices, we may disable it to reduce memory
+	  footprint, about 20KB on x86_64 platform.
+
+config SND_HRTIMER
+	tristate "HR-timer backend support"
+	depends on HIGH_RES_TIMERS
+	select SND_TIMER
+	help
+	  Say Y here to enable HR-timer backend for ALSA timer.  ALSA uses
+	  the hrtimer as a precise timing source. The ALSA sequencer code
+	  also can use this timing source.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hrtimer.
+
+config SND_DYNAMIC_MINORS
+	bool "Dynamic device file minor numbers"
+	help
+	  If you say Y here, the minor numbers of ALSA device files in
+	  /dev/snd/ are allocated dynamically.  This allows you to have
+	  more than 8 sound cards, but requires a dynamic device file
+	  system like udev.
+
+	  If you are unsure about this, say N here.
+
+config SND_MAX_CARDS
+	int "Max number of sound cards"
+	range 4 256
+	default 32
+	depends on SND_DYNAMIC_MINORS
+	help
+	  Specify the max number of sound cards that can be assigned
+	  on a single machine.
+
+config SND_SUPPORT_OLD_API
+	bool "Support old ALSA API"
+	default y
+	help
+	  Say Y here to support the obsolete ALSA PCM API (ver.0.9.0 rc3
+	  or older).
+
+config SND_PROC_FS
+	bool "Sound Proc FS Support" if EXPERT
+	depends on PROC_FS
+	default y
+	help
+	  Say 'N' to disable Sound proc FS, which may reduce code size about
+	  9KB on x86_64 platform.
+	  If unsure say Y.
+
+config SND_VERBOSE_PROCFS
+	bool "Verbose procfs contents"
+	depends on SND_PROC_FS
+	default y
+	help
+	  Say Y here to include code for verbose procfs contents (provides
+	  useful information to developers when a problem occurs).  On the
+	  other side, it makes the ALSA subsystem larger.
+
+config SND_VERBOSE_PRINTK
+	bool "Verbose printk"
+	help
+	  Say Y here to enable verbose log messages.  These messages
+	  will help to identify source file and position containing
+	  printed messages.
+
+	  You don't need this unless you're debugging ALSA.
+
+config SND_CTL_FAST_LOOKUP
+	bool "Fast lookup of control elements" if EXPERT
+	default y
+	select XARRAY_MULTI
+	help
+	  This option enables the faster lookup of control elements.
+	  It will consume more memory because of the additional Xarray.
+	  If you want to choose the memory footprint over the performance
+	  inevitably, turn this off.
+
+config SND_DEBUG
+	bool "Debug"
+	help
+	  Say Y here to enable ALSA debug code.
+
+config SND_DEBUG_VERBOSE
+	bool "More verbose debug"
+	depends on SND_DEBUG
+	help
+	  Say Y here to enable extra-verbose debugging messages.
+
+	  Let me repeat: it enables EXTRA-VERBOSE DEBUGGING messages.
+	  So, say Y only if you are ready to be annoyed.
+
+config SND_PCM_XRUN_DEBUG
+	bool "Enable PCM ring buffer overrun/underrun debugging"
+	default n
+	depends on SND_DEBUG && SND_VERBOSE_PROCFS
+	help
+	  Say Y to enable the PCM ring buffer overrun/underrun debugging.
+	  It is usually not required, but if you have trouble with
+	  sound clicking when system is loaded, it may help to determine
+	  the process or driver which causes the scheduling gaps.
+
+config SND_CTL_INPUT_VALIDATION
+	bool "Validate input data to control API"
+	help
+	  Say Y to enable the additional validation for the input data to
+	  each control element, including the value range checks.
+	  An error is returned from ALSA core for invalid inputs without
+	  passing to the driver.  This is a kind of hardening for drivers
+	  that have no proper error checks, at the cost of a slight
+	  performance overhead.
+
+config SND_CTL_DEBUG
+	bool "Enable debugging feature for control API"
+	depends on SND_DEBUG
+	help
+	  Say Y to enable the debugging feature for ALSA control API.
+	  It performs the additional sanity-checks for each control element
+	  read access, such as whether the values returned from the driver
+	  are in the proper ranges or the check of the invalid access at
+	  out-of-array areas.  The error is printed when the driver gives
+	  such unexpected values.
+	  When you develop a driver that deals with control elements, it's
+	  strongly recommended to try this one once and verify whether you see
+	  any relevant errors or not.
+
+config SND_JACK_INJECTION_DEBUG
+	bool "Sound jack injection interface via debugfs"
+	depends on SND_JACK && SND_DEBUG && DEBUG_FS
+	help
+	  This option can be used to enable or disable sound jack
+	  software injection.
+	  Say Y if you are debugging via jack injection interface.
+	  If unsure select "N".
+
+config SND_VMASTER
+	bool
+
+config SND_DMA_SGBUF
+	def_bool y
+	depends on X86
+
+config SND_CTL_LED
+	tristate
+	select NEW_LEDS if SND_CTL_LED
+	select LEDS_TRIGGERS if SND_CTL_LED
+	select LEDS_TRIGGER_AUDIO if SND_CTL_LED
+
+source "sound/core/seq/Kconfig"
diff --git a/sound/core/Makefile b/sound/core/Makefile
new file mode 100644
index 0000000000..a6b444ee28
--- /dev/null
+++ b/sound/core/Makefile
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for ALSA
+# Copyright (c) 1999,2001 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-y     := sound.o init.o memory.o control.o misc.o device.o
+ifneq ($(CONFIG_SND_PROC_FS),)
+snd-y += info.o
+snd-$(CONFIG_SND_OSSEMUL) += info_oss.o
+endif
+snd-$(CONFIG_ISA_DMA_API) += isadma.o
+snd-$(CONFIG_SND_OSSEMUL) += sound_oss.o
+snd-$(CONFIG_SND_VMASTER) += vmaster.o
+snd-$(CONFIG_SND_JACK)	  += ctljack.o jack.o
+
+snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_misc.o \
+		pcm_memory.o memalloc.o
+snd-pcm-$(CONFIG_SND_PCM_TIMER) += pcm_timer.o
+snd-pcm-$(CONFIG_SND_PCM_ELD) += pcm_drm_eld.o
+snd-pcm-$(CONFIG_SND_PCM_IEC958) += pcm_iec958.o
+
+# for trace-points
+CFLAGS_pcm_lib.o := -I$(src)
+CFLAGS_pcm_native.o := -I$(src)
+
+snd-pcm-dmaengine-objs := pcm_dmaengine.o
+
+snd-ctl-led-objs  := control_led.o
+snd-rawmidi-objs  := rawmidi.o
+snd-ump-objs      := ump.o
+snd-ump-$(CONFIG_SND_UMP_LEGACY_RAWMIDI) += ump_convert.o
+snd-timer-objs    := timer.o
+snd-hrtimer-objs  := hrtimer.o
+snd-rtctimer-objs := rtctimer.o
+snd-hwdep-objs    := hwdep.o
+snd-seq-device-objs := seq_device.o
+
+snd-compress-objs := compress_offload.o
+
+obj-$(CONFIG_SND) 		+= snd.o
+obj-$(CONFIG_SND_CTL_LED)	+= snd-ctl-led.o
+obj-$(CONFIG_SND_HWDEP)		+= snd-hwdep.o
+obj-$(CONFIG_SND_TIMER)		+= snd-timer.o
+obj-$(CONFIG_SND_HRTIMER)	+= snd-hrtimer.o
+obj-$(CONFIG_SND_PCM)		+= snd-pcm.o
+obj-$(CONFIG_SND_DMAENGINE_PCM)	+= snd-pcm-dmaengine.o
+obj-$(CONFIG_SND_SEQ_DEVICE)	+= snd-seq-device.o
+obj-$(CONFIG_SND_RAWMIDI)	+= snd-rawmidi.o
+obj-$(CONFIG_SND_UMP)		+= snd-ump.o
+
+obj-$(CONFIG_SND_OSSEMUL)	+= oss/
+obj-$(CONFIG_SND_SEQUENCER)	+= seq/
+
+obj-$(CONFIG_SND_COMPRESS_OFFLOAD)	+= snd-compress.o
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
new file mode 100644
index 0000000000..619371aa99
--- /dev/null
+++ b/sound/core/compress_offload.c
@@ -0,0 +1,1209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  compress_core.c - compress offload core
+ *
+ *  Copyright (C) 2011 Intel Corporation
+ *  Authors:	Vinod Koul <vinod.koul@linux.intel.com>
+ *		Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#define FORMAT(fmt) "%s: %d: " fmt, __func__, __LINE__
+#define pr_fmt(fmt) KBUILD_MODNAME ": " FORMAT(fmt)
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/math64.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/uio.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/compat.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/info.h>
+#include <sound/compress_params.h>
+#include <sound/compress_offload.h>
+#include <sound/compress_driver.h>
+
+/* struct snd_compr_codec_caps overflows the ioctl bit size for some
+ * architectures, so we need to disable the relevant ioctls.
+ */
+#if _IOC_SIZEBITS < 14
+#define COMPR_CODEC_CAPS_OVERFLOW
+#endif
+
+/* TODO:
+ * - add substream support for multiple devices in case of
+ *	SND_DYNAMIC_MINORS is not used
+ * - Multiple node representation
+ *	driver should be able to register multiple nodes
+ */
+
+struct snd_compr_file {
+	unsigned long caps;
+	struct snd_compr_stream stream;
+};
+
+static void error_delayed_work(struct work_struct *work);
+
+/*
+ * a note on stream states used:
+ * we use following states in the compressed core
+ * SNDRV_PCM_STATE_OPEN: When stream has been opened.
+ * SNDRV_PCM_STATE_SETUP: When stream has been initialized. This is done by
+ *	calling SNDRV_COMPRESS_SET_PARAMS. Running streams will come to this
+ *	state at stop by calling SNDRV_COMPRESS_STOP, or at end of drain.
+ * SNDRV_PCM_STATE_PREPARED: When a stream has been written to (for
+ *	playback only). User after setting up stream writes the data buffer
+ *	before starting the stream.
+ * SNDRV_PCM_STATE_RUNNING: When stream has been started and is
+ *	decoding/encoding and rendering/capturing data.
+ * SNDRV_PCM_STATE_DRAINING: When stream is draining current data. This is done
+ *	by calling SNDRV_COMPRESS_DRAIN.
+ * SNDRV_PCM_STATE_PAUSED: When stream is paused. This is done by calling
+ *	SNDRV_COMPRESS_PAUSE. It can be stopped or resumed by calling
+ *	SNDRV_COMPRESS_STOP or SNDRV_COMPRESS_RESUME respectively.
+ */
+static int snd_compr_open(struct inode *inode, struct file *f)
+{
+	struct snd_compr *compr;
+	struct snd_compr_file *data;
+	struct snd_compr_runtime *runtime;
+	enum snd_compr_direction dirn;
+	int maj = imajor(inode);
+	int ret;
+
+	if ((f->f_flags & O_ACCMODE) == O_WRONLY)
+		dirn = SND_COMPRESS_PLAYBACK;
+	else if ((f->f_flags & O_ACCMODE) == O_RDONLY)
+		dirn = SND_COMPRESS_CAPTURE;
+	else
+		return -EINVAL;
+
+	if (maj == snd_major)
+		compr = snd_lookup_minor_data(iminor(inode),
+					SNDRV_DEVICE_TYPE_COMPRESS);
+	else
+		return -EBADFD;
+
+	if (compr == NULL) {
+		pr_err("no device data!!!\n");
+		return -ENODEV;
+	}
+
+	if (dirn != compr->direction) {
+		pr_err("this device doesn't support this direction\n");
+		snd_card_unref(compr->card);
+		return -EINVAL;
+	}
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		snd_card_unref(compr->card);
+		return -ENOMEM;
+	}
+
+	INIT_DELAYED_WORK(&data->stream.error_work, error_delayed_work);
+
+	data->stream.ops = compr->ops;
+	data->stream.direction = dirn;
+	data->stream.private_data = compr->private_data;
+	data->stream.device = compr;
+	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
+	if (!runtime) {
+		kfree(data);
+		snd_card_unref(compr->card);
+		return -ENOMEM;
+	}
+	runtime->state = SNDRV_PCM_STATE_OPEN;
+	init_waitqueue_head(&runtime->sleep);
+	data->stream.runtime = runtime;
+	f->private_data = (void *)data;
+	mutex_lock(&compr->lock);
+	ret = compr->ops->open(&data->stream);
+	mutex_unlock(&compr->lock);
+	if (ret) {
+		kfree(runtime);
+		kfree(data);
+	}
+	snd_card_unref(compr->card);
+	return ret;
+}
+
+static int snd_compr_free(struct inode *inode, struct file *f)
+{
+	struct snd_compr_file *data = f->private_data;
+	struct snd_compr_runtime *runtime = data->stream.runtime;
+
+	cancel_delayed_work_sync(&data->stream.error_work);
+
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_RUNNING:
+	case SNDRV_PCM_STATE_DRAINING:
+	case SNDRV_PCM_STATE_PAUSED:
+		data->stream.ops->trigger(&data->stream, SNDRV_PCM_TRIGGER_STOP);
+		break;
+	default:
+		break;
+	}
+
+	data->stream.ops->free(&data->stream);
+	if (!data->stream.runtime->dma_buffer_p)
+		kfree(data->stream.runtime->buffer);
+	kfree(data->stream.runtime);
+	kfree(data);
+	return 0;
+}
+
+static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
+		struct snd_compr_tstamp *tstamp)
+{
+	if (!stream->ops->pointer)
+		return -ENOTSUPP;
+	stream->ops->pointer(stream, tstamp);
+	pr_debug("dsp consumed till %d total %d bytes\n",
+		tstamp->byte_offset, tstamp->copied_total);
+	if (stream->direction == SND_COMPRESS_PLAYBACK)
+		stream->runtime->total_bytes_transferred = tstamp->copied_total;
+	else
+		stream->runtime->total_bytes_available = tstamp->copied_total;
+	return 0;
+}
+
+static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
+		struct snd_compr_avail *avail)
+{
+	memset(avail, 0, sizeof(*avail));
+	snd_compr_update_tstamp(stream, &avail->tstamp);
+	/* Still need to return avail even if tstamp can't be filled in */
+
+	if (stream->runtime->total_bytes_available == 0 &&
+			stream->runtime->state == SNDRV_PCM_STATE_SETUP &&
+			stream->direction == SND_COMPRESS_PLAYBACK) {
+		pr_debug("detected init and someone forgot to do a write\n");
+		return stream->runtime->buffer_size;
+	}
+	pr_debug("app wrote %lld, DSP consumed %lld\n",
+			stream->runtime->total_bytes_available,
+			stream->runtime->total_bytes_transferred);
+	if (stream->runtime->total_bytes_available ==
+				stream->runtime->total_bytes_transferred) {
+		if (stream->direction == SND_COMPRESS_PLAYBACK) {
+			pr_debug("both pointers are same, returning full avail\n");
+			return stream->runtime->buffer_size;
+		} else {
+			pr_debug("both pointers are same, returning no avail\n");
+			return 0;
+		}
+	}
+
+	avail->avail = stream->runtime->total_bytes_available -
+			stream->runtime->total_bytes_transferred;
+	if (stream->direction == SND_COMPRESS_PLAYBACK)
+		avail->avail = stream->runtime->buffer_size - avail->avail;
+
+	pr_debug("ret avail as %lld\n", avail->avail);
+	return avail->avail;
+}
+
+static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
+{
+	struct snd_compr_avail avail;
+
+	return snd_compr_calc_avail(stream, &avail);
+}
+
+static int
+snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_avail ioctl_avail;
+	size_t avail;
+
+	avail = snd_compr_calc_avail(stream, &ioctl_avail);
+	ioctl_avail.avail = avail;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+		return -EBADFD;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
+	default:
+		break;
+	}
+
+	if (copy_to_user((__u64 __user *)arg,
+				&ioctl_avail, sizeof(ioctl_avail)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_compr_write_data(struct snd_compr_stream *stream,
+	       const char __user *buf, size_t count)
+{
+	void *dstn;
+	size_t copy;
+	struct snd_compr_runtime *runtime = stream->runtime;
+	/* 64-bit Modulus */
+	u64 app_pointer = div64_u64(runtime->total_bytes_available,
+				    runtime->buffer_size);
+	app_pointer = runtime->total_bytes_available -
+		      (app_pointer * runtime->buffer_size);
+
+	dstn = runtime->buffer + app_pointer;
+	pr_debug("copying %ld at %lld\n",
+			(unsigned long)count, app_pointer);
+	if (count < runtime->buffer_size - app_pointer) {
+		if (copy_from_user(dstn, buf, count))
+			return -EFAULT;
+	} else {
+		copy = runtime->buffer_size - app_pointer;
+		if (copy_from_user(dstn, buf, copy))
+			return -EFAULT;
+		if (copy_from_user(runtime->buffer, buf + copy, count - copy))
+			return -EFAULT;
+	}
+	/* if DSP cares, let it know data has been written */
+	if (stream->ops->ack)
+		stream->ops->ack(stream, count);
+	return count;
+}
+
+static ssize_t snd_compr_write(struct file *f, const char __user *buf,
+		size_t count, loff_t *offset)
+{
+	struct snd_compr_file *data = f->private_data;
+	struct snd_compr_stream *stream;
+	size_t avail;
+	int retval;
+
+	if (snd_BUG_ON(!data))
+		return -EFAULT;
+
+	stream = &data->stream;
+	mutex_lock(&stream->device->lock);
+	/* write is allowed when stream is running or has been steup */
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_RUNNING:
+		break;
+	default:
+		mutex_unlock(&stream->device->lock);
+		return -EBADFD;
+	}
+
+	avail = snd_compr_get_avail(stream);
+	pr_debug("avail returned %ld\n", (unsigned long)avail);
+	/* calculate how much we can write to buffer */
+	if (avail > count)
+		avail = count;
+
+	if (stream->ops->copy) {
+		char __user* cbuf = (char __user*)buf;
+		retval = stream->ops->copy(stream, cbuf, avail);
+	} else {
+		retval = snd_compr_write_data(stream, buf, avail);
+	}
+	if (retval > 0)
+		stream->runtime->total_bytes_available += retval;
+
+	/* while initiating the stream, write should be called before START
+	 * call, so in setup move state */
+	if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
+		stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
+		pr_debug("stream prepared, Houston we are good to go\n");
+	}
+
+	mutex_unlock(&stream->device->lock);
+	return retval;
+}
+
+
+static ssize_t snd_compr_read(struct file *f, char __user *buf,
+		size_t count, loff_t *offset)
+{
+	struct snd_compr_file *data = f->private_data;
+	struct snd_compr_stream *stream;
+	size_t avail;
+	int retval;
+
+	if (snd_BUG_ON(!data))
+		return -EFAULT;
+
+	stream = &data->stream;
+	mutex_lock(&stream->device->lock);
+
+	/* read is allowed when stream is running, paused, draining and setup
+	 * (yes setup is state which we transition to after stop, so if user
+	 * wants to read data after stop we allow that)
+	 */
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_SUSPENDED:
+	case SNDRV_PCM_STATE_DISCONNECTED:
+		retval = -EBADFD;
+		goto out;
+	case SNDRV_PCM_STATE_XRUN:
+		retval = -EPIPE;
+		goto out;
+	}
+
+	avail = snd_compr_get_avail(stream);
+	pr_debug("avail returned %ld\n", (unsigned long)avail);
+	/* calculate how much we can read from buffer */
+	if (avail > count)
+		avail = count;
+
+	if (stream->ops->copy) {
+		retval = stream->ops->copy(stream, buf, avail);
+	} else {
+		retval = -ENXIO;
+		goto out;
+	}
+	if (retval > 0)
+		stream->runtime->total_bytes_transferred += retval;
+
+out:
+	mutex_unlock(&stream->device->lock);
+	return retval;
+}
+
+static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
+{
+	return -ENXIO;
+}
+
+static __poll_t snd_compr_get_poll(struct snd_compr_stream *stream)
+{
+	if (stream->direction == SND_COMPRESS_PLAYBACK)
+		return EPOLLOUT | EPOLLWRNORM;
+	else
+		return EPOLLIN | EPOLLRDNORM;
+}
+
+static __poll_t snd_compr_poll(struct file *f, poll_table *wait)
+{
+	struct snd_compr_file *data = f->private_data;
+	struct snd_compr_stream *stream;
+	size_t avail;
+	__poll_t retval = 0;
+
+	if (snd_BUG_ON(!data))
+		return EPOLLERR;
+
+	stream = &data->stream;
+
+	mutex_lock(&stream->device->lock);
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_XRUN:
+		retval = snd_compr_get_poll(stream) | EPOLLERR;
+		goto out;
+	default:
+		break;
+	}
+
+	poll_wait(f, &stream->runtime->sleep, wait);
+
+	avail = snd_compr_get_avail(stream);
+	pr_debug("avail is %ld\n", (unsigned long)avail);
+	/* check if we have at least one fragment to fill */
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_DRAINING:
+		/* stream has been woken up after drain is complete
+		 * draining done so set stream state to stopped
+		 */
+		retval = snd_compr_get_poll(stream);
+		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+		break;
+	case SNDRV_PCM_STATE_RUNNING:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+		if (avail >= stream->runtime->fragment_size)
+			retval = snd_compr_get_poll(stream);
+		break;
+	default:
+		retval = snd_compr_get_poll(stream) | EPOLLERR;
+		break;
+	}
+out:
+	mutex_unlock(&stream->device->lock);
+	return retval;
+}
+
+static int
+snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
+{
+	int retval;
+	struct snd_compr_caps caps;
+
+	if (!stream->ops->get_caps)
+		return -ENXIO;
+
+	memset(&caps, 0, sizeof(caps));
+	retval = stream->ops->get_caps(stream, &caps);
+	if (retval)
+		goto out;
+	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
+		retval = -EFAULT;
+out:
+	return retval;
+}
+
+#ifndef COMPR_CODEC_CAPS_OVERFLOW
+static int
+snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
+{
+	int retval;
+	struct snd_compr_codec_caps *caps;
+
+	if (!stream->ops->get_codec_caps)
+		return -ENXIO;
+
+	caps = kzalloc(sizeof(*caps), GFP_KERNEL);
+	if (!caps)
+		return -ENOMEM;
+
+	retval = stream->ops->get_codec_caps(stream, caps);
+	if (retval)
+		goto out;
+	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
+		retval = -EFAULT;
+
+out:
+	kfree(caps);
+	return retval;
+}
+#endif /* !COMPR_CODEC_CAPS_OVERFLOW */
+
+int snd_compr_malloc_pages(struct snd_compr_stream *stream, size_t size)
+{
+	struct snd_dma_buffer *dmab;
+	int ret;
+
+	if (snd_BUG_ON(!(stream) || !(stream)->runtime))
+		return -EINVAL;
+	dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
+	if (!dmab)
+		return -ENOMEM;
+	dmab->dev = stream->dma_buffer.dev;
+	ret = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev, size, dmab);
+	if (ret < 0) {
+		kfree(dmab);
+		return ret;
+	}
+
+	snd_compr_set_runtime_buffer(stream, dmab);
+	stream->runtime->dma_bytes = size;
+	return 1;
+}
+EXPORT_SYMBOL(snd_compr_malloc_pages);
+
+int snd_compr_free_pages(struct snd_compr_stream *stream)
+{
+	struct snd_compr_runtime *runtime;
+
+	if (snd_BUG_ON(!(stream) || !(stream)->runtime))
+		return -EINVAL;
+	runtime = stream->runtime;
+	if (runtime->dma_area == NULL)
+		return 0;
+	if (runtime->dma_buffer_p != &stream->dma_buffer) {
+		/* It's a newly allocated buffer. Release it now. */
+		snd_dma_free_pages(runtime->dma_buffer_p);
+		kfree(runtime->dma_buffer_p);
+	}
+
+	snd_compr_set_runtime_buffer(stream, NULL);
+	return 0;
+}
+EXPORT_SYMBOL(snd_compr_free_pages);
+
+/* revisit this with snd_pcm_preallocate_xxx */
+static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
+		struct snd_compr_params *params)
+{
+	unsigned int buffer_size;
+	void *buffer = NULL;
+
+	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
+	if (stream->ops->copy) {
+		buffer = NULL;
+		/* if copy is defined the driver will be required to copy
+		 * the data from core
+		 */
+	} else {
+		if (stream->runtime->dma_buffer_p) {
+
+			if (buffer_size > stream->runtime->dma_buffer_p->bytes)
+				dev_err(stream->device->dev,
+						"Not enough DMA buffer");
+			else
+				buffer = stream->runtime->dma_buffer_p->area;
+
+		} else {
+			buffer = kmalloc(buffer_size, GFP_KERNEL);
+		}
+
+		if (!buffer)
+			return -ENOMEM;
+	}
+	stream->runtime->fragment_size = params->buffer.fragment_size;
+	stream->runtime->fragments = params->buffer.fragments;
+	stream->runtime->buffer = buffer;
+	stream->runtime->buffer_size = buffer_size;
+	return 0;
+}
+
+static int snd_compress_check_input(struct snd_compr_params *params)
+{
+	/* first let's check the buffer parameter's */
+	if (params->buffer.fragment_size == 0 ||
+	    params->buffer.fragments > U32_MAX / params->buffer.fragment_size ||
+	    params->buffer.fragments == 0)
+		return -EINVAL;
+
+	/* now codec parameters */
+	if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
+		return -EINVAL;
+
+	if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int
+snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_params *params;
+	int retval;
+
+	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN || stream->next_track) {
+		/*
+		 * we should allow parameter change only when stream has been
+		 * opened not in other cases
+		 */
+		params = memdup_user((void __user *)arg, sizeof(*params));
+		if (IS_ERR(params))
+			return PTR_ERR(params);
+
+		retval = snd_compress_check_input(params);
+		if (retval)
+			goto out;
+
+		retval = snd_compr_allocate_buffer(stream, params);
+		if (retval) {
+			retval = -ENOMEM;
+			goto out;
+		}
+
+		retval = stream->ops->set_params(stream, params);
+		if (retval)
+			goto out;
+
+		if (stream->next_track)
+			goto out;
+
+		stream->metadata_set = false;
+		stream->next_track = false;
+
+		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+	} else {
+		return -EPERM;
+	}
+out:
+	kfree(params);
+	return retval;
+}
+
+static int
+snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_codec *params;
+	int retval;
+
+	if (!stream->ops->get_params)
+		return -EBADFD;
+
+	params = kzalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+	retval = stream->ops->get_params(stream, params);
+	if (retval)
+		goto out;
+	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
+		retval = -EFAULT;
+
+out:
+	kfree(params);
+	return retval;
+}
+
+static int
+snd_compr_get_metadata(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_metadata metadata;
+	int retval;
+
+	if (!stream->ops->get_metadata)
+		return -ENXIO;
+
+	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
+		return -EFAULT;
+
+	retval = stream->ops->get_metadata(stream, &metadata);
+	if (retval != 0)
+		return retval;
+
+	if (copy_to_user((void __user *)arg, &metadata, sizeof(metadata)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int
+snd_compr_set_metadata(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_metadata metadata;
+	int retval;
+
+	if (!stream->ops->set_metadata)
+		return -ENXIO;
+	/*
+	* we should allow parameter change only when stream has been
+	* opened not in other cases
+	*/
+	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
+		return -EFAULT;
+
+	retval = stream->ops->set_metadata(stream, &metadata);
+	stream->metadata_set = true;
+
+	return retval;
+}
+
+static inline int
+snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_tstamp tstamp = {0};
+	int ret;
+
+	ret = snd_compr_update_tstamp(stream, &tstamp);
+	if (ret == 0)
+		ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
+			&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
+	return ret;
+}
+
+static int snd_compr_pause(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_RUNNING:
+		retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
+		if (!retval)
+			stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
+		break;
+	case SNDRV_PCM_STATE_DRAINING:
+		if (!stream->device->use_pause_in_draining)
+			return -EPERM;
+		retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
+		if (!retval)
+			stream->pause_in_draining = true;
+		break;
+	default:
+		return -EPERM;
+	}
+	return retval;
+}
+
+static int snd_compr_resume(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_PAUSED:
+		retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
+		if (!retval)
+			stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
+		break;
+	case SNDRV_PCM_STATE_DRAINING:
+		if (!stream->pause_in_draining)
+			return -EPERM;
+		retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
+		if (!retval)
+			stream->pause_in_draining = false;
+		break;
+	default:
+		return -EPERM;
+	}
+	return retval;
+}
+
+static int snd_compr_start(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_SETUP:
+		if (stream->direction != SND_COMPRESS_CAPTURE)
+			return -EPERM;
+		break;
+	case SNDRV_PCM_STATE_PREPARED:
+		break;
+	default:
+		return -EPERM;
+	}
+
+	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
+	if (!retval)
+		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
+	return retval;
+}
+
+static int snd_compr_stop(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_PREPARED:
+		return -EPERM;
+	default:
+		break;
+	}
+
+	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
+	if (!retval) {
+		/* clear flags and stop any drain wait */
+		stream->partial_drain = false;
+		stream->metadata_set = false;
+		stream->pause_in_draining = false;
+		snd_compr_drain_notify(stream);
+		stream->runtime->total_bytes_available = 0;
+		stream->runtime->total_bytes_transferred = 0;
+	}
+	return retval;
+}
+
+static void error_delayed_work(struct work_struct *work)
+{
+	struct snd_compr_stream *stream;
+
+	stream = container_of(work, struct snd_compr_stream, error_work.work);
+
+	mutex_lock(&stream->device->lock);
+
+	stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
+	wake_up(&stream->runtime->sleep);
+
+	mutex_unlock(&stream->device->lock);
+}
+
+/**
+ * snd_compr_stop_error: Report a fatal error on a stream
+ * @stream: pointer to stream
+ * @state: state to transition the stream to
+ *
+ * Stop the stream and set its state.
+ *
+ * Should be called with compressed device lock held.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_compr_stop_error(struct snd_compr_stream *stream,
+			 snd_pcm_state_t state)
+{
+	if (stream->runtime->state == state)
+		return 0;
+
+	stream->runtime->state = state;
+
+	pr_debug("Changing state to: %d\n", state);
+
+	queue_delayed_work(system_power_efficient_wq, &stream->error_work, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_compr_stop_error);
+
+static int snd_compress_wait_for_drain(struct snd_compr_stream *stream)
+{
+	int ret;
+
+	/*
+	 * We are called with lock held. So drop the lock while we wait for
+	 * drain complete notification from the driver
+	 *
+	 * It is expected that driver will notify the drain completion and then
+	 * stream will be moved to SETUP state, even if draining resulted in an
+	 * error. We can trigger next track after this.
+	 */
+	stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
+	mutex_unlock(&stream->device->lock);
+
+	/* we wait for drain to complete here, drain can return when
+	 * interruption occurred, wait returned error or success.
+	 * For the first two cases we don't do anything different here and
+	 * return after waking up
+	 */
+
+	ret = wait_event_interruptible(stream->runtime->sleep,
+			(stream->runtime->state != SNDRV_PCM_STATE_DRAINING));
+	if (ret == -ERESTARTSYS)
+		pr_debug("wait aborted by a signal\n");
+	else if (ret)
+		pr_debug("wait for drain failed with %d\n", ret);
+
+
+	wake_up(&stream->runtime->sleep);
+	mutex_lock(&stream->device->lock);
+
+	return ret;
+}
+
+static int snd_compr_drain(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+		return -EPERM;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
+	default:
+		break;
+	}
+
+	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
+	if (retval) {
+		pr_debug("SND_COMPR_TRIGGER_DRAIN failed %d\n", retval);
+		wake_up(&stream->runtime->sleep);
+		return retval;
+	}
+
+	return snd_compress_wait_for_drain(stream);
+}
+
+static int snd_compr_next_track(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	/* only a running stream can transition to next track */
+	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
+		return -EPERM;
+
+	/* next track doesn't have any meaning for capture streams */
+	if (stream->direction == SND_COMPRESS_CAPTURE)
+		return -EPERM;
+
+	/* you can signal next track if this is intended to be a gapless stream
+	 * and current track metadata is set
+	 */
+	if (stream->metadata_set == false)
+		return -EPERM;
+
+	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_NEXT_TRACK);
+	if (retval != 0)
+		return retval;
+	stream->metadata_set = false;
+	stream->next_track = true;
+	return 0;
+}
+
+static int snd_compr_partial_drain(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	switch (stream->runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+		return -EPERM;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
+	default:
+		break;
+	}
+
+	/* partial drain doesn't have any meaning for capture streams */
+	if (stream->direction == SND_COMPRESS_CAPTURE)
+		return -EPERM;
+
+	/* stream can be drained only when next track has been signalled */
+	if (stream->next_track == false)
+		return -EPERM;
+
+	stream->partial_drain = true;
+	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
+	if (retval) {
+		pr_debug("Partial drain returned failure\n");
+		wake_up(&stream->runtime->sleep);
+		return retval;
+	}
+
+	stream->next_track = false;
+	return snd_compress_wait_for_drain(stream);
+}
+
+static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+{
+	struct snd_compr_file *data = f->private_data;
+	struct snd_compr_stream *stream;
+	int retval = -ENOTTY;
+
+	if (snd_BUG_ON(!data))
+		return -EFAULT;
+
+	stream = &data->stream;
+
+	mutex_lock(&stream->device->lock);
+	switch (_IOC_NR(cmd)) {
+	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
+		retval = put_user(SNDRV_COMPRESS_VERSION,
+				(int __user *)arg) ? -EFAULT : 0;
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
+		retval = snd_compr_get_caps(stream, arg);
+		break;
+#ifndef COMPR_CODEC_CAPS_OVERFLOW
+	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
+		retval = snd_compr_get_codec_caps(stream, arg);
+		break;
+#endif
+	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
+		retval = snd_compr_set_params(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
+		retval = snd_compr_get_params(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_SET_METADATA):
+		retval = snd_compr_set_metadata(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_GET_METADATA):
+		retval = snd_compr_get_metadata(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
+		retval = snd_compr_tstamp(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
+		retval = snd_compr_ioctl_avail(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
+		retval = snd_compr_pause(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_RESUME):
+		retval = snd_compr_resume(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_START):
+		retval = snd_compr_start(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_STOP):
+		retval = snd_compr_stop(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
+		retval = snd_compr_drain(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_PARTIAL_DRAIN):
+		retval = snd_compr_partial_drain(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_NEXT_TRACK):
+		retval = snd_compr_next_track(stream);
+		break;
+
+	}
+	mutex_unlock(&stream->device->lock);
+	return retval;
+}
+
+/* support of 32bit userspace on 64bit platforms */
+#ifdef CONFIG_COMPAT
+static long snd_compr_ioctl_compat(struct file *file, unsigned int cmd,
+						unsigned long arg)
+{
+	return snd_compr_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations snd_compr_file_ops = {
+		.owner =	THIS_MODULE,
+		.open =		snd_compr_open,
+		.release =	snd_compr_free,
+		.write =	snd_compr_write,
+		.read =		snd_compr_read,
+		.unlocked_ioctl = snd_compr_ioctl,
+#ifdef CONFIG_COMPAT
+		.compat_ioctl = snd_compr_ioctl_compat,
+#endif
+		.mmap =		snd_compr_mmap,
+		.poll =		snd_compr_poll,
+};
+
+static int snd_compress_dev_register(struct snd_device *device)
+{
+	int ret;
+	struct snd_compr *compr;
+
+	if (snd_BUG_ON(!device || !device->device_data))
+		return -EBADFD;
+	compr = device->device_data;
+
+	pr_debug("reg device %s, direction %d\n", compr->name,
+			compr->direction);
+	/* register compressed device */
+	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS,
+				  compr->card, compr->device,
+				  &snd_compr_file_ops, compr, compr->dev);
+	if (ret < 0) {
+		pr_err("snd_register_device failed %d\n", ret);
+		return ret;
+	}
+	return ret;
+
+}
+
+static int snd_compress_dev_disconnect(struct snd_device *device)
+{
+	struct snd_compr *compr;
+
+	compr = device->device_data;
+	snd_unregister_device(compr->dev);
+	return 0;
+}
+
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+static void snd_compress_proc_info_read(struct snd_info_entry *entry,
+					struct snd_info_buffer *buffer)
+{
+	struct snd_compr *compr = (struct snd_compr *)entry->private_data;
+
+	snd_iprintf(buffer, "card: %d\n", compr->card->number);
+	snd_iprintf(buffer, "device: %d\n", compr->device);
+	snd_iprintf(buffer, "stream: %s\n",
+			compr->direction == SND_COMPRESS_PLAYBACK
+				? "PLAYBACK" : "CAPTURE");
+	snd_iprintf(buffer, "id: %s\n", compr->id);
+}
+
+static int snd_compress_proc_init(struct snd_compr *compr)
+{
+	struct snd_info_entry *entry;
+	char name[16];
+
+	sprintf(name, "compr%i", compr->device);
+	entry = snd_info_create_card_entry(compr->card, name,
+					   compr->card->proc_root);
+	if (!entry)
+		return -ENOMEM;
+	entry->mode = S_IFDIR | 0555;
+	compr->proc_root = entry;
+
+	entry = snd_info_create_card_entry(compr->card, "info",
+					   compr->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, compr,
+				      snd_compress_proc_info_read);
+	compr->proc_info_entry = entry;
+
+	return 0;
+}
+
+static void snd_compress_proc_done(struct snd_compr *compr)
+{
+	snd_info_free_entry(compr->proc_info_entry);
+	compr->proc_info_entry = NULL;
+	snd_info_free_entry(compr->proc_root);
+	compr->proc_root = NULL;
+}
+
+static inline void snd_compress_set_id(struct snd_compr *compr, const char *id)
+{
+	strscpy(compr->id, id, sizeof(compr->id));
+}
+#else
+static inline int snd_compress_proc_init(struct snd_compr *compr)
+{
+	return 0;
+}
+
+static inline void snd_compress_proc_done(struct snd_compr *compr)
+{
+}
+
+static inline void snd_compress_set_id(struct snd_compr *compr, const char *id)
+{
+}
+#endif
+
+static int snd_compress_dev_free(struct snd_device *device)
+{
+	struct snd_compr *compr;
+
+	compr = device->device_data;
+	snd_compress_proc_done(compr);
+	put_device(compr->dev);
+	return 0;
+}
+
+/**
+ * snd_compress_new: create new compress device
+ * @card: sound card pointer
+ * @device: device number
+ * @dirn: device direction, should be of type enum snd_compr_direction
+ * @id: ID string
+ * @compr: compress device pointer
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_compress_new(struct snd_card *card, int device,
+			int dirn, const char *id, struct snd_compr *compr)
+{
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_compress_dev_free,
+		.dev_register = snd_compress_dev_register,
+		.dev_disconnect = snd_compress_dev_disconnect,
+	};
+	int ret;
+
+	compr->card = card;
+	compr->device = device;
+	compr->direction = dirn;
+	mutex_init(&compr->lock);
+
+	snd_compress_set_id(compr, id);
+
+	ret = snd_device_alloc(&compr->dev, card);
+	if (ret)
+		return ret;
+	dev_set_name(compr->dev, "comprC%iD%i", card->number, device);
+
+	ret = snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
+	if (ret == 0)
+		snd_compress_proc_init(compr);
+	else
+		put_device(compr->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_compress_new);
+
+MODULE_DESCRIPTION("ALSA Compressed offload framework");
+MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/sound/core/control.c b/sound/core/control.c
new file mode 100644
index 0000000000..59c8658966
--- /dev/null
+++ b/sound/core/control.c
@@ -0,0 +1,2562 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Routines for driver control interface
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/threads.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/math64.h>
+#include <linux/sched/signal.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/info.h>
+#include <sound/control.h>
+
+// Max allocation size for user controls.
+static int max_user_ctl_alloc_size = 8 * 1024 * 1024;
+module_param_named(max_user_ctl_alloc_size, max_user_ctl_alloc_size, int, 0444);
+MODULE_PARM_DESC(max_user_ctl_alloc_size, "Max allocation size for user controls");
+
+#define MAX_CONTROL_COUNT	1028
+
+struct snd_kctl_ioctl {
+	struct list_head list;		/* list of all ioctls */
+	snd_kctl_ioctl_func_t fioctl;
+};
+
+static DECLARE_RWSEM(snd_ioctl_rwsem);
+static DECLARE_RWSEM(snd_ctl_layer_rwsem);
+static LIST_HEAD(snd_control_ioctls);
+#ifdef CONFIG_COMPAT
+static LIST_HEAD(snd_control_compat_ioctls);
+#endif
+static struct snd_ctl_layer_ops *snd_ctl_layer;
+
+static int snd_ctl_remove_locked(struct snd_card *card,
+				 struct snd_kcontrol *kcontrol);
+
+static int snd_ctl_open(struct inode *inode, struct file *file)
+{
+	unsigned long flags;
+	struct snd_card *card;
+	struct snd_ctl_file *ctl;
+	int i, err;
+
+	err = stream_open(inode, file);
+	if (err < 0)
+		return err;
+
+	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
+	if (!card) {
+		err = -ENODEV;
+		goto __error1;
+	}
+	err = snd_card_file_add(card, file);
+	if (err < 0) {
+		err = -ENODEV;
+		goto __error1;
+	}
+	if (!try_module_get(card->module)) {
+		err = -EFAULT;
+		goto __error2;
+	}
+	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+	if (ctl == NULL) {
+		err = -ENOMEM;
+		goto __error;
+	}
+	INIT_LIST_HEAD(&ctl->events);
+	init_waitqueue_head(&ctl->change_sleep);
+	spin_lock_init(&ctl->read_lock);
+	ctl->card = card;
+	for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
+		ctl->preferred_subdevice[i] = -1;
+	ctl->pid = get_pid(task_pid(current));
+	file->private_data = ctl;
+	write_lock_irqsave(&card->ctl_files_rwlock, flags);
+	list_add_tail(&ctl->list, &card->ctl_files);
+	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+	snd_card_unref(card);
+	return 0;
+
+      __error:
+	module_put(card->module);
+      __error2:
+	snd_card_file_remove(card, file);
+      __error1:
+	if (card)
+		snd_card_unref(card);
+      	return err;
+}
+
+static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
+{
+	unsigned long flags;
+	struct snd_kctl_event *cread;
+
+	spin_lock_irqsave(&ctl->read_lock, flags);
+	while (!list_empty(&ctl->events)) {
+		cread = snd_kctl_event(ctl->events.next);
+		list_del(&cread->list);
+		kfree(cread);
+	}
+	spin_unlock_irqrestore(&ctl->read_lock, flags);
+}
+
+static int snd_ctl_release(struct inode *inode, struct file *file)
+{
+	unsigned long flags;
+	struct snd_card *card;
+	struct snd_ctl_file *ctl;
+	struct snd_kcontrol *control;
+	unsigned int idx;
+
+	ctl = file->private_data;
+	file->private_data = NULL;
+	card = ctl->card;
+	write_lock_irqsave(&card->ctl_files_rwlock, flags);
+	list_del(&ctl->list);
+	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+	down_write(&card->controls_rwsem);
+	list_for_each_entry(control, &card->controls, list)
+		for (idx = 0; idx < control->count; idx++)
+			if (control->vd[idx].owner == ctl)
+				control->vd[idx].owner = NULL;
+	up_write(&card->controls_rwsem);
+	snd_fasync_free(ctl->fasync);
+	snd_ctl_empty_read_queue(ctl);
+	put_pid(ctl->pid);
+	kfree(ctl);
+	module_put(card->module);
+	snd_card_file_remove(card, file);
+	return 0;
+}
+
+/**
+ * snd_ctl_notify - Send notification to user-space for a control change
+ * @card: the card to send notification
+ * @mask: the event mask, SNDRV_CTL_EVENT_*
+ * @id: the ctl element id to send notification
+ *
+ * This function adds an event record with the given id and mask, appends
+ * to the list and wakes up the user-space for notification.  This can be
+ * called in the atomic context.
+ */
+void snd_ctl_notify(struct snd_card *card, unsigned int mask,
+		    struct snd_ctl_elem_id *id)
+{
+	unsigned long flags;
+	struct snd_ctl_file *ctl;
+	struct snd_kctl_event *ev;
+
+	if (snd_BUG_ON(!card || !id))
+		return;
+	if (card->shutdown)
+		return;
+	read_lock_irqsave(&card->ctl_files_rwlock, flags);
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
+	card->mixer_oss_change_count++;
+#endif
+	list_for_each_entry(ctl, &card->ctl_files, list) {
+		if (!ctl->subscribed)
+			continue;
+		spin_lock(&ctl->read_lock);
+		list_for_each_entry(ev, &ctl->events, list) {
+			if (ev->id.numid == id->numid) {
+				ev->mask |= mask;
+				goto _found;
+			}
+		}
+		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
+		if (ev) {
+			ev->id = *id;
+			ev->mask = mask;
+			list_add_tail(&ev->list, &ctl->events);
+		} else {
+			dev_err(card->dev, "No memory available to allocate event\n");
+		}
+	_found:
+		wake_up(&ctl->change_sleep);
+		spin_unlock(&ctl->read_lock);
+		snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN);
+	}
+	read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+}
+EXPORT_SYMBOL(snd_ctl_notify);
+
+/**
+ * snd_ctl_notify_one - Send notification to user-space for a control change
+ * @card: the card to send notification
+ * @mask: the event mask, SNDRV_CTL_EVENT_*
+ * @kctl: the pointer with the control instance
+ * @ioff: the additional offset to the control index
+ *
+ * This function calls snd_ctl_notify() and does additional jobs
+ * like LED state changes.
+ */
+void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
+			struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct snd_ctl_elem_id id = kctl->id;
+	struct snd_ctl_layer_ops *lops;
+
+	id.index += ioff;
+	id.numid += ioff;
+	snd_ctl_notify(card, mask, &id);
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		lops->lnotify(card, mask, kctl, ioff);
+	up_read(&snd_ctl_layer_rwsem);
+}
+EXPORT_SYMBOL(snd_ctl_notify_one);
+
+/**
+ * snd_ctl_new - create a new control instance with some elements
+ * @kctl: the pointer to store new control instance
+ * @count: the number of elements in this control
+ * @access: the default access flags for elements in this control
+ * @file: given when locking these elements
+ *
+ * Allocates a memory object for a new control instance. The instance has
+ * elements as many as the given number (@count). Each element has given
+ * access permissions (@access). Each element is locked when @file is given.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
+		       unsigned int access, struct snd_ctl_file *file)
+{
+	unsigned int idx;
+
+	if (count == 0 || count > MAX_CONTROL_COUNT)
+		return -EINVAL;
+
+	*kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
+	if (!*kctl)
+		return -ENOMEM;
+
+	for (idx = 0; idx < count; idx++) {
+		(*kctl)->vd[idx].access = access;
+		(*kctl)->vd[idx].owner = file;
+	}
+	(*kctl)->count = count;
+
+	return 0;
+}
+
+/**
+ * snd_ctl_new1 - create a control instance from the template
+ * @ncontrol: the initialization record
+ * @private_data: the private data to set
+ *
+ * Allocates a new struct snd_kcontrol instance and initialize from the given
+ * template.  When the access field of ncontrol is 0, it's assumed as
+ * READWRITE access. When the count field is 0, it's assumes as one.
+ *
+ * Return: The pointer of the newly generated instance, or %NULL on failure.
+ */
+struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
+				  void *private_data)
+{
+	struct snd_kcontrol *kctl;
+	unsigned int count;
+	unsigned int access;
+	int err;
+
+	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
+		return NULL;
+
+	count = ncontrol->count;
+	if (count == 0)
+		count = 1;
+
+	access = ncontrol->access;
+	if (access == 0)
+		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
+	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		   SNDRV_CTL_ELEM_ACCESS_VOLATILE |
+		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
+		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
+		   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
+		   SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK |
+		   SNDRV_CTL_ELEM_ACCESS_LED_MASK |
+		   SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
+
+	err = snd_ctl_new(&kctl, count, access, NULL);
+	if (err < 0)
+		return NULL;
+
+	/* The 'numid' member is decided when calling snd_ctl_add(). */
+	kctl->id.iface = ncontrol->iface;
+	kctl->id.device = ncontrol->device;
+	kctl->id.subdevice = ncontrol->subdevice;
+	if (ncontrol->name) {
+		strscpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
+		if (strcmp(ncontrol->name, kctl->id.name) != 0)
+			pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
+				ncontrol->name, kctl->id.name);
+	}
+	kctl->id.index = ncontrol->index;
+
+	kctl->info = ncontrol->info;
+	kctl->get = ncontrol->get;
+	kctl->put = ncontrol->put;
+	kctl->tlv.p = ncontrol->tlv.p;
+
+	kctl->private_value = ncontrol->private_value;
+	kctl->private_data = private_data;
+
+	return kctl;
+}
+EXPORT_SYMBOL(snd_ctl_new1);
+
+/**
+ * snd_ctl_free_one - release the control instance
+ * @kcontrol: the control instance
+ *
+ * Releases the control instance created via snd_ctl_new()
+ * or snd_ctl_new1().
+ * Don't call this after the control was added to the card.
+ */
+void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
+{
+	if (kcontrol) {
+		if (kcontrol->private_free)
+			kcontrol->private_free(kcontrol);
+		kfree(kcontrol);
+	}
+}
+EXPORT_SYMBOL(snd_ctl_free_one);
+
+static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
+					  unsigned int count)
+{
+	struct snd_kcontrol *kctl;
+
+	/* Make sure that the ids assigned to the control do not wrap around */
+	if (card->last_numid >= UINT_MAX - count)
+		card->last_numid = 0;
+
+	list_for_each_entry(kctl, &card->controls, list) {
+		if (kctl->id.numid < card->last_numid + 1 + count &&
+		    kctl->id.numid + kctl->count > card->last_numid + 1) {
+		    	card->last_numid = kctl->id.numid + kctl->count - 1;
+			return true;
+		}
+	}
+	return false;
+}
+
+static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
+{
+	unsigned int iter = 100000;
+
+	while (snd_ctl_remove_numid_conflict(card, count)) {
+		if (--iter == 0) {
+			/* this situation is very unlikely */
+			dev_err(card->dev, "unable to allocate new control numid\n");
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+/* check whether the given id is contained in the given kctl */
+static bool elem_id_matches(const struct snd_kcontrol *kctl,
+			    const struct snd_ctl_elem_id *id)
+{
+	return kctl->id.iface == id->iface &&
+		kctl->id.device == id->device &&
+		kctl->id.subdevice == id->subdevice &&
+		!strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)) &&
+		kctl->id.index <= id->index &&
+		kctl->id.index + kctl->count > id->index;
+}
+
+#ifdef CONFIG_SND_CTL_FAST_LOOKUP
+/* Compute a hash key for the corresponding ctl id
+ * It's for the name lookup, hence the numid is excluded.
+ * The hash key is bound in LONG_MAX to be used for Xarray key.
+ */
+#define MULTIPLIER	37
+static unsigned long get_ctl_id_hash(const struct snd_ctl_elem_id *id)
+{
+	int i;
+	unsigned long h;
+
+	h = id->iface;
+	h = MULTIPLIER * h + id->device;
+	h = MULTIPLIER * h + id->subdevice;
+	for (i = 0; i < SNDRV_CTL_ELEM_ID_NAME_MAXLEN && id->name[i]; i++)
+		h = MULTIPLIER * h + id->name[i];
+	h = MULTIPLIER * h + id->index;
+	h &= LONG_MAX;
+	return h;
+}
+
+/* add hash entries to numid and ctl xarray tables */
+static void add_hash_entries(struct snd_card *card,
+			     struct snd_kcontrol *kcontrol)
+{
+	struct snd_ctl_elem_id id = kcontrol->id;
+	int i;
+
+	xa_store_range(&card->ctl_numids, kcontrol->id.numid,
+		       kcontrol->id.numid + kcontrol->count - 1,
+		       kcontrol, GFP_KERNEL);
+
+	for (i = 0; i < kcontrol->count; i++) {
+		id.index = kcontrol->id.index + i;
+		if (xa_insert(&card->ctl_hash, get_ctl_id_hash(&id),
+			      kcontrol, GFP_KERNEL)) {
+			/* skip hash for this entry, noting we had collision */
+			card->ctl_hash_collision = true;
+			dev_dbg(card->dev, "ctl_hash collision %d:%s:%d\n",
+				id.iface, id.name, id.index);
+		}
+	}
+}
+
+/* remove hash entries that have been added */
+static void remove_hash_entries(struct snd_card *card,
+				struct snd_kcontrol *kcontrol)
+{
+	struct snd_ctl_elem_id id = kcontrol->id;
+	struct snd_kcontrol *matched;
+	unsigned long h;
+	int i;
+
+	for (i = 0; i < kcontrol->count; i++) {
+		xa_erase(&card->ctl_numids, id.numid);
+		h = get_ctl_id_hash(&id);
+		matched = xa_load(&card->ctl_hash, h);
+		if (matched && (matched == kcontrol ||
+				elem_id_matches(matched, &id)))
+			xa_erase(&card->ctl_hash, h);
+		id.index++;
+		id.numid++;
+	}
+}
+#else /* CONFIG_SND_CTL_FAST_LOOKUP */
+static inline void add_hash_entries(struct snd_card *card,
+				    struct snd_kcontrol *kcontrol)
+{
+}
+static inline void remove_hash_entries(struct snd_card *card,
+				       struct snd_kcontrol *kcontrol)
+{
+}
+#endif /* CONFIG_SND_CTL_FAST_LOOKUP */
+
+enum snd_ctl_add_mode {
+	CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
+};
+
+/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
+static int __snd_ctl_add_replace(struct snd_card *card,
+				 struct snd_kcontrol *kcontrol,
+				 enum snd_ctl_add_mode mode)
+{
+	struct snd_ctl_elem_id id;
+	unsigned int idx;
+	struct snd_kcontrol *old;
+	int err;
+
+	lockdep_assert_held_write(&card->controls_rwsem);
+
+	id = kcontrol->id;
+	if (id.index > UINT_MAX - kcontrol->count)
+		return -EINVAL;
+
+	old = snd_ctl_find_id_locked(card, &id);
+	if (!old) {
+		if (mode == CTL_REPLACE)
+			return -EINVAL;
+	} else {
+		if (mode == CTL_ADD_EXCLUSIVE) {
+			dev_err(card->dev,
+				"control %i:%i:%i:%s:%i is already present\n",
+				id.iface, id.device, id.subdevice, id.name,
+				id.index);
+			return -EBUSY;
+		}
+
+		err = snd_ctl_remove_locked(card, old);
+		if (err < 0)
+			return err;
+	}
+
+	if (snd_ctl_find_hole(card, kcontrol->count) < 0)
+		return -ENOMEM;
+
+	list_add_tail(&kcontrol->list, &card->controls);
+	card->controls_count += kcontrol->count;
+	kcontrol->id.numid = card->last_numid + 1;
+	card->last_numid += kcontrol->count;
+
+	add_hash_entries(card, kcontrol);
+
+	for (idx = 0; idx < kcontrol->count; idx++)
+		snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
+
+	return 0;
+}
+
+static int snd_ctl_add_replace(struct snd_card *card,
+			       struct snd_kcontrol *kcontrol,
+			       enum snd_ctl_add_mode mode)
+{
+	int err = -EINVAL;
+
+	if (! kcontrol)
+		return err;
+	if (snd_BUG_ON(!card || !kcontrol->info))
+		goto error;
+
+	down_write(&card->controls_rwsem);
+	err = __snd_ctl_add_replace(card, kcontrol, mode);
+	up_write(&card->controls_rwsem);
+	if (err < 0)
+		goto error;
+	return 0;
+
+ error:
+	snd_ctl_free_one(kcontrol);
+	return err;
+}
+
+/**
+ * snd_ctl_add - add the control instance to the card
+ * @card: the card instance
+ * @kcontrol: the control instance to add
+ *
+ * Adds the control instance created via snd_ctl_new() or
+ * snd_ctl_new1() to the given card. Assigns also an unique
+ * numid used for fast search.
+ *
+ * It frees automatically the control which cannot be added.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ *
+ */
+int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
+{
+	return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
+}
+EXPORT_SYMBOL(snd_ctl_add);
+
+/**
+ * snd_ctl_replace - replace the control instance of the card
+ * @card: the card instance
+ * @kcontrol: the control instance to replace
+ * @add_on_replace: add the control if not already added
+ *
+ * Replaces the given control.  If the given control does not exist
+ * and the add_on_replace flag is set, the control is added.  If the
+ * control exists, it is destroyed first.
+ *
+ * It frees automatically the control which cannot be added or replaced.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
+		    bool add_on_replace)
+{
+	return snd_ctl_add_replace(card, kcontrol,
+				   add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
+}
+EXPORT_SYMBOL(snd_ctl_replace);
+
+static int __snd_ctl_remove(struct snd_card *card,
+			    struct snd_kcontrol *kcontrol,
+			    bool remove_hash)
+{
+	unsigned int idx;
+
+	lockdep_assert_held_write(&card->controls_rwsem);
+
+	if (snd_BUG_ON(!card || !kcontrol))
+		return -EINVAL;
+	list_del(&kcontrol->list);
+
+	if (remove_hash)
+		remove_hash_entries(card, kcontrol);
+
+	card->controls_count -= kcontrol->count;
+	for (idx = 0; idx < kcontrol->count; idx++)
+		snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx);
+	snd_ctl_free_one(kcontrol);
+	return 0;
+}
+
+static inline int snd_ctl_remove_locked(struct snd_card *card,
+					struct snd_kcontrol *kcontrol)
+{
+	return __snd_ctl_remove(card, kcontrol, true);
+}
+
+/**
+ * snd_ctl_remove - remove the control from the card and release it
+ * @card: the card instance
+ * @kcontrol: the control instance to remove
+ *
+ * Removes the control from the card and then releases the instance.
+ * You don't need to call snd_ctl_free_one().
+ *
+ * Return: 0 if successful, or a negative error code on failure.
+ *
+ * Note that this function takes card->controls_rwsem lock internally.
+ */
+int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
+{
+	int ret;
+
+	down_write(&card->controls_rwsem);
+	ret = snd_ctl_remove_locked(card, kcontrol);
+	up_write(&card->controls_rwsem);
+	return ret;
+}
+EXPORT_SYMBOL(snd_ctl_remove);
+
+/**
+ * snd_ctl_remove_id - remove the control of the given id and release it
+ * @card: the card instance
+ * @id: the control id to remove
+ *
+ * Finds the control instance with the given id, removes it from the
+ * card list and releases it.
+ *
+ * Return: 0 if successful, or a negative error code on failure.
+ */
+int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
+{
+	struct snd_kcontrol *kctl;
+	int ret;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
+		return -ENOENT;
+	}
+	ret = snd_ctl_remove_locked(card, kctl);
+	up_write(&card->controls_rwsem);
+	return ret;
+}
+EXPORT_SYMBOL(snd_ctl_remove_id);
+
+/**
+ * snd_ctl_remove_user_ctl - remove and release the unlocked user control
+ * @file: active control handle
+ * @id: the control id to remove
+ *
+ * Finds the control instance with the given id, removes it from the
+ * card list and releases it.
+ *
+ * Return: 0 if successful, or a negative error code on failure.
+ */
+static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
+				   struct snd_ctl_elem_id *id)
+{
+	struct snd_card *card = file->card;
+	struct snd_kcontrol *kctl;
+	int idx, ret;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, id);
+	if (kctl == NULL) {
+		ret = -ENOENT;
+		goto error;
+	}
+	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
+		ret = -EINVAL;
+		goto error;
+	}
+	for (idx = 0; idx < kctl->count; idx++)
+		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
+			ret = -EBUSY;
+			goto error;
+		}
+	ret = snd_ctl_remove_locked(card, kctl);
+error:
+	up_write(&card->controls_rwsem);
+	return ret;
+}
+
+/**
+ * snd_ctl_activate_id - activate/inactivate the control of the given id
+ * @card: the card instance
+ * @id: the control id to activate/inactivate
+ * @active: non-zero to activate
+ *
+ * Finds the control instance with the given id, and activate or
+ * inactivate the control together with notification, if changed.
+ * The given ID data is filled with full information.
+ *
+ * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
+ */
+int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
+			int active)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_volatile *vd;
+	unsigned int index_offset;
+	int ret;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, id);
+	if (kctl == NULL) {
+		ret = -ENOENT;
+		goto unlock;
+	}
+	index_offset = snd_ctl_get_ioff(kctl, id);
+	vd = &kctl->vd[index_offset];
+	ret = 0;
+	if (active) {
+		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
+			goto unlock;
+		vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
+	} else {
+		if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
+			goto unlock;
+		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
+	}
+	snd_ctl_build_ioff(id, kctl, index_offset);
+	downgrade_write(&card->controls_rwsem);
+	snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset);
+	up_read(&card->controls_rwsem);
+	return 1;
+
+ unlock:
+	up_write(&card->controls_rwsem);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
+
+/**
+ * snd_ctl_rename_id - replace the id of a control on the card
+ * @card: the card instance
+ * @src_id: the old id
+ * @dst_id: the new id
+ *
+ * Finds the control with the old id from the card, and replaces the
+ * id with the new one.
+ *
+ * The function tries to keep the already assigned numid while replacing
+ * the rest.
+ *
+ * Note that this function should be used only in the card initialization
+ * phase.  Calling after the card instantiation may cause issues with
+ * user-space expecting persistent numids.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
+		      struct snd_ctl_elem_id *dst_id)
+{
+	struct snd_kcontrol *kctl;
+	int saved_numid;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, src_id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
+		return -ENOENT;
+	}
+	saved_numid = kctl->id.numid;
+	remove_hash_entries(card, kctl);
+	kctl->id = *dst_id;
+	kctl->id.numid = saved_numid;
+	add_hash_entries(card, kctl);
+	up_write(&card->controls_rwsem);
+	return 0;
+}
+EXPORT_SYMBOL(snd_ctl_rename_id);
+
+/**
+ * snd_ctl_rename - rename the control on the card
+ * @card: the card instance
+ * @kctl: the control to rename
+ * @name: the new name
+ *
+ * Renames the specified control on the card to the new name.
+ *
+ * Note that this function takes card->controls_rwsem lock internally.
+ */
+void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl,
+		    const char *name)
+{
+	down_write(&card->controls_rwsem);
+	remove_hash_entries(card, kctl);
+
+	if (strscpy(kctl->id.name, name, sizeof(kctl->id.name)) < 0)
+		pr_warn("ALSA: Renamed control new name '%s' truncated to '%s'\n",
+			name, kctl->id.name);
+
+	add_hash_entries(card, kctl);
+	up_write(&card->controls_rwsem);
+}
+EXPORT_SYMBOL(snd_ctl_rename);
+
+#ifndef CONFIG_SND_CTL_FAST_LOOKUP
+static struct snd_kcontrol *
+snd_ctl_find_numid_slow(struct snd_card *card, unsigned int numid)
+{
+	struct snd_kcontrol *kctl;
+
+	list_for_each_entry(kctl, &card->controls, list) {
+		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
+			return kctl;
+	}
+	return NULL;
+}
+#endif /* !CONFIG_SND_CTL_FAST_LOOKUP */
+
+/**
+ * snd_ctl_find_numid_locked - find the control instance with the given number-id
+ * @card: the card instance
+ * @numid: the number-id to search
+ *
+ * Finds the control instance with the given number-id from the card.
+ *
+ * The caller must down card->controls_rwsem before calling this function
+ * (if the race condition can happen).
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ */
+struct snd_kcontrol *
+snd_ctl_find_numid_locked(struct snd_card *card, unsigned int numid)
+{
+	if (snd_BUG_ON(!card || !numid))
+		return NULL;
+	lockdep_assert_held(&card->controls_rwsem);
+#ifdef CONFIG_SND_CTL_FAST_LOOKUP
+	return xa_load(&card->ctl_numids, numid);
+#else
+	return snd_ctl_find_numid_slow(card, numid);
+#endif
+}
+EXPORT_SYMBOL(snd_ctl_find_numid_locked);
+
+/**
+ * snd_ctl_find_numid - find the control instance with the given number-id
+ * @card: the card instance
+ * @numid: the number-id to search
+ *
+ * Finds the control instance with the given number-id from the card.
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ *
+ * Note that this function takes card->controls_rwsem lock internally.
+ */
+struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card,
+					unsigned int numid)
+{
+	struct snd_kcontrol *kctl;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_numid_locked(card, numid);
+	up_read(&card->controls_rwsem);
+	return kctl;
+}
+EXPORT_SYMBOL(snd_ctl_find_numid);
+
+/**
+ * snd_ctl_find_id_locked - find the control instance with the given id
+ * @card: the card instance
+ * @id: the id to search
+ *
+ * Finds the control instance with the given id from the card.
+ *
+ * The caller must down card->controls_rwsem before calling this function
+ * (if the race condition can happen).
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ */
+struct snd_kcontrol *snd_ctl_find_id_locked(struct snd_card *card,
+					    const struct snd_ctl_elem_id *id)
+{
+	struct snd_kcontrol *kctl;
+
+	if (snd_BUG_ON(!card || !id))
+		return NULL;
+	lockdep_assert_held(&card->controls_rwsem);
+	if (id->numid != 0)
+		return snd_ctl_find_numid_locked(card, id->numid);
+#ifdef CONFIG_SND_CTL_FAST_LOOKUP
+	kctl = xa_load(&card->ctl_hash, get_ctl_id_hash(id));
+	if (kctl && elem_id_matches(kctl, id))
+		return kctl;
+	if (!card->ctl_hash_collision)
+		return NULL; /* we can rely on only hash table */
+#endif
+	/* no matching in hash table - try all as the last resort */
+	list_for_each_entry(kctl, &card->controls, list)
+		if (elem_id_matches(kctl, id))
+			return kctl;
+
+	return NULL;
+}
+EXPORT_SYMBOL(snd_ctl_find_id_locked);
+
+/**
+ * snd_ctl_find_id - find the control instance with the given id
+ * @card: the card instance
+ * @id: the id to search
+ *
+ * Finds the control instance with the given id from the card.
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ *
+ * Note that this function takes card->controls_rwsem lock internally.
+ */
+struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
+				     const struct snd_ctl_elem_id *id)
+{
+	struct snd_kcontrol *kctl;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, id);
+	up_read(&card->controls_rwsem);
+	return kctl;
+}
+EXPORT_SYMBOL(snd_ctl_find_id);
+
+static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
+			     unsigned int cmd, void __user *arg)
+{
+	struct snd_ctl_card_info *info;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (! info)
+		return -ENOMEM;
+	down_read(&snd_ioctl_rwsem);
+	info->card = card->number;
+	strscpy(info->id, card->id, sizeof(info->id));
+	strscpy(info->driver, card->driver, sizeof(info->driver));
+	strscpy(info->name, card->shortname, sizeof(info->name));
+	strscpy(info->longname, card->longname, sizeof(info->longname));
+	strscpy(info->mixername, card->mixername, sizeof(info->mixername));
+	strscpy(info->components, card->components, sizeof(info->components));
+	up_read(&snd_ioctl_rwsem);
+	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
+		kfree(info);
+		return -EFAULT;
+	}
+	kfree(info);
+	return 0;
+}
+
+static int snd_ctl_elem_list(struct snd_card *card,
+			     struct snd_ctl_elem_list *list)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_ctl_elem_id id;
+	unsigned int offset, space, jidx;
+	int err = 0;
+
+	offset = list->offset;
+	space = list->space;
+
+	down_read(&card->controls_rwsem);
+	list->count = card->controls_count;
+	list->used = 0;
+	if (space > 0) {
+		list_for_each_entry(kctl, &card->controls, list) {
+			if (offset >= kctl->count) {
+				offset -= kctl->count;
+				continue;
+			}
+			for (jidx = offset; jidx < kctl->count; jidx++) {
+				snd_ctl_build_ioff(&id, kctl, jidx);
+				if (copy_to_user(list->pids + list->used, &id,
+						 sizeof(id))) {
+					err = -EFAULT;
+					goto out;
+				}
+				list->used++;
+				if (!--space)
+					goto out;
+			}
+			offset = 0;
+		}
+	}
+ out:
+	up_read(&card->controls_rwsem);
+	return err;
+}
+
+static int snd_ctl_elem_list_user(struct snd_card *card,
+				  struct snd_ctl_elem_list __user *_list)
+{
+	struct snd_ctl_elem_list list;
+	int err;
+
+	if (copy_from_user(&list, _list, sizeof(list)))
+		return -EFAULT;
+	err = snd_ctl_elem_list(card, &list);
+	if (err)
+		return err;
+	if (copy_to_user(_list, &list, sizeof(list)))
+		return -EFAULT;
+
+	return 0;
+}
+
+/* Check whether the given kctl info is valid */
+static int snd_ctl_check_elem_info(struct snd_card *card,
+				   const struct snd_ctl_elem_info *info)
+{
+	static const unsigned int max_value_counts[] = {
+		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= 128,
+		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= 128,
+		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
+		[SNDRV_CTL_ELEM_TYPE_BYTES]	= 512,
+		[SNDRV_CTL_ELEM_TYPE_IEC958]	= 1,
+		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
+	};
+
+	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) {
+		if (card)
+			dev_err(card->dev,
+				"control %i:%i:%i:%s:%i: invalid type %d\n",
+				info->id.iface, info->id.device,
+				info->id.subdevice, info->id.name,
+				info->id.index, info->type);
+		return -EINVAL;
+	}
+	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
+	    info->value.enumerated.items == 0) {
+		if (card)
+			dev_err(card->dev,
+				"control %i:%i:%i:%s:%i: zero enum items\n",
+				info->id.iface, info->id.device,
+				info->id.subdevice, info->id.name,
+				info->id.index);
+		return -EINVAL;
+	}
+	if (info->count > max_value_counts[info->type]) {
+		if (card)
+			dev_err(card->dev,
+				"control %i:%i:%i:%s:%i: invalid count %d\n",
+				info->id.iface, info->id.device,
+				info->id.subdevice, info->id.name,
+				info->id.index, info->count);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* The capacity of struct snd_ctl_elem_value.value.*/
+static const unsigned int value_sizes[] = {
+	[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= sizeof(long),
+	[SNDRV_CTL_ELEM_TYPE_INTEGER]	= sizeof(long),
+	[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
+	[SNDRV_CTL_ELEM_TYPE_BYTES]	= sizeof(unsigned char),
+	[SNDRV_CTL_ELEM_TYPE_IEC958]	= sizeof(struct snd_aes_iec958),
+	[SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
+};
+
+/* fill the remaining snd_ctl_elem_value data with the given pattern */
+static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
+				      struct snd_ctl_elem_info *info,
+				      u32 pattern)
+{
+	size_t offset = value_sizes[info->type] * info->count;
+
+	offset = DIV_ROUND_UP(offset, sizeof(u32));
+	memset32((u32 *)control->value.bytes.data + offset, pattern,
+		 sizeof(control->value) / sizeof(u32) - offset);
+}
+
+/* check whether the given integer ctl value is valid */
+static int sanity_check_int_value(struct snd_card *card,
+				  const struct snd_ctl_elem_value *control,
+				  const struct snd_ctl_elem_info *info,
+				  int i, bool print_error)
+{
+	long long lval, lmin, lmax, lstep;
+	u64 rem;
+
+	switch (info->type) {
+	default:
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+		lval = control->value.integer.value[i];
+		lmin = 0;
+		lmax = 1;
+		lstep = 0;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		lval = control->value.integer.value[i];
+		lmin = info->value.integer.min;
+		lmax = info->value.integer.max;
+		lstep = info->value.integer.step;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		lval = control->value.integer64.value[i];
+		lmin = info->value.integer64.min;
+		lmax = info->value.integer64.max;
+		lstep = info->value.integer64.step;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		lval = control->value.enumerated.item[i];
+		lmin = 0;
+		lmax = info->value.enumerated.items - 1;
+		lstep = 0;
+		break;
+	}
+
+	if (lval < lmin || lval > lmax) {
+		if (print_error)
+			dev_err(card->dev,
+				"control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n",
+				control->id.iface, control->id.device,
+				control->id.subdevice, control->id.name,
+				control->id.index, lval, lmin, lmax, i);
+		return -EINVAL;
+	}
+	if (lstep) {
+		div64_u64_rem(lval, lstep, &rem);
+		if (rem) {
+			if (print_error)
+				dev_err(card->dev,
+					"control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n",
+					control->id.iface, control->id.device,
+					control->id.subdevice, control->id.name,
+					control->id.index, lval, lstep, i);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/* check whether the all input values are valid for the given elem value */
+static int sanity_check_input_values(struct snd_card *card,
+				     const struct snd_ctl_elem_value *control,
+				     const struct snd_ctl_elem_info *info,
+				     bool print_error)
+{
+	int i, ret;
+
+	switch (info->type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		for (i = 0; i < info->count; i++) {
+			ret = sanity_check_int_value(card, control, info, i,
+						     print_error);
+			if (ret < 0)
+				return ret;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/* perform sanity checks to the given snd_ctl_elem_value object */
+static int sanity_check_elem_value(struct snd_card *card,
+				   const struct snd_ctl_elem_value *control,
+				   const struct snd_ctl_elem_info *info,
+				   u32 pattern)
+{
+	size_t offset;
+	int ret;
+	u32 *p;
+
+	ret = sanity_check_input_values(card, control, info, true);
+	if (ret < 0)
+		return ret;
+
+	/* check whether the remaining area kept untouched */
+	offset = value_sizes[info->type] * info->count;
+	offset = DIV_ROUND_UP(offset, sizeof(u32));
+	p = (u32 *)control->value.bytes.data + offset;
+	for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) {
+		if (*p != pattern) {
+			ret = -EINVAL;
+			break;
+		}
+		*p = 0; /* clear the checked area */
+	}
+
+	return ret;
+}
+
+static int __snd_ctl_elem_info(struct snd_card *card,
+			       struct snd_kcontrol *kctl,
+			       struct snd_ctl_elem_info *info,
+			       struct snd_ctl_file *ctl)
+{
+	struct snd_kcontrol_volatile *vd;
+	unsigned int index_offset;
+	int result;
+
+#ifdef CONFIG_SND_DEBUG
+	info->access = 0;
+#endif
+	result = snd_power_ref_and_wait(card);
+	if (!result)
+		result = kctl->info(kctl, info);
+	snd_power_unref(card);
+	if (result >= 0) {
+		snd_BUG_ON(info->access);
+		index_offset = snd_ctl_get_ioff(kctl, &info->id);
+		vd = &kctl->vd[index_offset];
+		snd_ctl_build_ioff(&info->id, kctl, index_offset);
+		info->access = vd->access;
+		if (vd->owner) {
+			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
+			if (vd->owner == ctl)
+				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
+			info->owner = pid_vnr(vd->owner->pid);
+		} else {
+			info->owner = -1;
+		}
+		if (!snd_ctl_skip_validation(info) &&
+		    snd_ctl_check_elem_info(card, info) < 0)
+			result = -EINVAL;
+	}
+	return result;
+}
+
+static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
+			     struct snd_ctl_elem_info *info)
+{
+	struct snd_card *card = ctl->card;
+	struct snd_kcontrol *kctl;
+	int result;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, &info->id);
+	if (kctl == NULL)
+		result = -ENOENT;
+	else
+		result = __snd_ctl_elem_info(card, kctl, info, ctl);
+	up_read(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
+				  struct snd_ctl_elem_info __user *_info)
+{
+	struct snd_ctl_elem_info info;
+	int result;
+
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	result = snd_ctl_elem_info(ctl, &info);
+	if (result < 0)
+		return result;
+	/* drop internal access flags */
+	info.access &= ~(SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK|
+			 SNDRV_CTL_ELEM_ACCESS_LED_MASK);
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return result;
+}
+
+static int snd_ctl_elem_read(struct snd_card *card,
+			     struct snd_ctl_elem_value *control)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_volatile *vd;
+	unsigned int index_offset;
+	struct snd_ctl_elem_info info;
+	const u32 pattern = 0xdeadbeef;
+	int ret;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, &control->id);
+	if (kctl == NULL) {
+		ret = -ENOENT;
+		goto unlock;
+	}
+
+	index_offset = snd_ctl_get_ioff(kctl, &control->id);
+	vd = &kctl->vd[index_offset];
+	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL) {
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	snd_ctl_build_ioff(&control->id, kctl, index_offset);
+
+#ifdef CONFIG_SND_CTL_DEBUG
+	/* info is needed only for validation */
+	memset(&info, 0, sizeof(info));
+	info.id = control->id;
+	ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
+	if (ret < 0)
+		goto unlock;
+#endif
+
+	if (!snd_ctl_skip_validation(&info))
+		fill_remaining_elem_value(control, &info, pattern);
+	ret = snd_power_ref_and_wait(card);
+	if (!ret)
+		ret = kctl->get(kctl, control);
+	snd_power_unref(card);
+	if (ret < 0)
+		goto unlock;
+	if (!snd_ctl_skip_validation(&info) &&
+	    sanity_check_elem_value(card, control, &info, pattern) < 0) {
+		dev_err(card->dev,
+			"control %i:%i:%i:%s:%i: access overflow\n",
+			control->id.iface, control->id.device,
+			control->id.subdevice, control->id.name,
+			control->id.index);
+		ret = -EINVAL;
+		goto unlock;
+	}
+unlock:
+	up_read(&card->controls_rwsem);
+	return ret;
+}
+
+static int snd_ctl_elem_read_user(struct snd_card *card,
+				  struct snd_ctl_elem_value __user *_control)
+{
+	struct snd_ctl_elem_value *control;
+	int result;
+
+	control = memdup_user(_control, sizeof(*control));
+	if (IS_ERR(control))
+		return PTR_ERR(control);
+
+	result = snd_ctl_elem_read(card, control);
+	if (result < 0)
+		goto error;
+
+	if (copy_to_user(_control, control, sizeof(*control)))
+		result = -EFAULT;
+ error:
+	kfree(control);
+	return result;
+}
+
+static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
+			      struct snd_ctl_elem_value *control)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_volatile *vd;
+	unsigned int index_offset;
+	int result;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, &control->id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
+		return -ENOENT;
+	}
+
+	index_offset = snd_ctl_get_ioff(kctl, &control->id);
+	vd = &kctl->vd[index_offset];
+	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
+	    (file && vd->owner && vd->owner != file)) {
+		up_write(&card->controls_rwsem);
+		return -EPERM;
+	}
+
+	snd_ctl_build_ioff(&control->id, kctl, index_offset);
+	result = snd_power_ref_and_wait(card);
+	/* validate input values */
+	if (IS_ENABLED(CONFIG_SND_CTL_INPUT_VALIDATION) && !result) {
+		struct snd_ctl_elem_info info;
+
+		memset(&info, 0, sizeof(info));
+		info.id = control->id;
+		result = __snd_ctl_elem_info(card, kctl, &info, NULL);
+		if (!result)
+			result = sanity_check_input_values(card, control, &info,
+							   false);
+	}
+	if (!result)
+		result = kctl->put(kctl, control);
+	snd_power_unref(card);
+	if (result < 0) {
+		up_write(&card->controls_rwsem);
+		return result;
+	}
+
+	if (result > 0) {
+		downgrade_write(&card->controls_rwsem);
+		snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
+		up_read(&card->controls_rwsem);
+	} else {
+		up_write(&card->controls_rwsem);
+	}
+
+	return 0;
+}
+
+static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
+				   struct snd_ctl_elem_value __user *_control)
+{
+	struct snd_ctl_elem_value *control;
+	struct snd_card *card;
+	int result;
+
+	control = memdup_user(_control, sizeof(*control));
+	if (IS_ERR(control))
+		return PTR_ERR(control);
+
+	card = file->card;
+	result = snd_ctl_elem_write(card, file, control);
+	if (result < 0)
+		goto error;
+
+	if (copy_to_user(_control, control, sizeof(*control)))
+		result = -EFAULT;
+ error:
+	kfree(control);
+	return result;
+}
+
+static int snd_ctl_elem_lock(struct snd_ctl_file *file,
+			     struct snd_ctl_elem_id __user *_id)
+{
+	struct snd_card *card = file->card;
+	struct snd_ctl_elem_id id;
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_volatile *vd;
+	int result;
+
+	if (copy_from_user(&id, _id, sizeof(id)))
+		return -EFAULT;
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, &id);
+	if (kctl == NULL) {
+		result = -ENOENT;
+	} else {
+		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
+		if (vd->owner != NULL)
+			result = -EBUSY;
+		else {
+			vd->owner = file;
+			result = 0;
+		}
+	}
+	up_write(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
+			       struct snd_ctl_elem_id __user *_id)
+{
+	struct snd_card *card = file->card;
+	struct snd_ctl_elem_id id;
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_volatile *vd;
+	int result;
+
+	if (copy_from_user(&id, _id, sizeof(id)))
+		return -EFAULT;
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, &id);
+	if (kctl == NULL) {
+		result = -ENOENT;
+	} else {
+		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
+		if (vd->owner == NULL)
+			result = -EINVAL;
+		else if (vd->owner != file)
+			result = -EPERM;
+		else {
+			vd->owner = NULL;
+			result = 0;
+		}
+	}
+	up_write(&card->controls_rwsem);
+	return result;
+}
+
+struct user_element {
+	struct snd_ctl_elem_info info;
+	struct snd_card *card;
+	char *elem_data;		/* element data */
+	unsigned long elem_data_size;	/* size of element data in bytes */
+	void *tlv_data;			/* TLV data */
+	unsigned long tlv_data_size;	/* TLV data size */
+	void *priv_data;		/* private data (like strings for enumerated type) */
+};
+
+// check whether the addition (in bytes) of user ctl element may overflow the limit.
+static bool check_user_elem_overflow(struct snd_card *card, ssize_t add)
+{
+	return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size;
+}
+
+static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_info *uinfo)
+{
+	struct user_element *ue = kcontrol->private_data;
+	unsigned int offset;
+
+	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
+	*uinfo = ue->info;
+	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
+
+	return 0;
+}
+
+static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
+				       struct snd_ctl_elem_info *uinfo)
+{
+	struct user_element *ue = kcontrol->private_data;
+	const char *names;
+	unsigned int item;
+	unsigned int offset;
+
+	item = uinfo->value.enumerated.item;
+
+	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
+	*uinfo = ue->info;
+	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
+
+	item = min(item, uinfo->value.enumerated.items - 1);
+	uinfo->value.enumerated.item = item;
+
+	names = ue->priv_data;
+	for (; item > 0; --item)
+		names += strlen(names) + 1;
+	strcpy(uinfo->value.enumerated.name, names);
+
+	return 0;
+}
+
+static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct user_element *ue = kcontrol->private_data;
+	unsigned int size = ue->elem_data_size;
+	char *src = ue->elem_data +
+			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
+
+	memcpy(&ucontrol->value, src, size);
+	return 0;
+}
+
+static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	int change;
+	struct user_element *ue = kcontrol->private_data;
+	unsigned int size = ue->elem_data_size;
+	char *dst = ue->elem_data +
+			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
+
+	change = memcmp(&ucontrol->value, dst, size) != 0;
+	if (change)
+		memcpy(dst, &ucontrol->value, size);
+	return change;
+}
+
+/* called in controls_rwsem write lock */
+static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
+			    unsigned int size)
+{
+	struct user_element *ue = kctl->private_data;
+	unsigned int *container;
+	unsigned int mask = 0;
+	int i;
+	int change;
+
+	lockdep_assert_held_write(&ue->card->controls_rwsem);
+
+	if (size > 1024 * 128)	/* sane value */
+		return -EINVAL;
+
+	// does the TLV size change cause overflow?
+	if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size)))
+		return -ENOMEM;
+
+	container = vmemdup_user(buf, size);
+	if (IS_ERR(container))
+		return PTR_ERR(container);
+
+	change = ue->tlv_data_size != size;
+	if (!change)
+		change = memcmp(ue->tlv_data, container, size) != 0;
+	if (!change) {
+		kvfree(container);
+		return 0;
+	}
+
+	if (ue->tlv_data == NULL) {
+		/* Now TLV data is available. */
+		for (i = 0; i < kctl->count; ++i)
+			kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
+		mask = SNDRV_CTL_EVENT_MASK_INFO;
+	} else {
+		ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
+		ue->tlv_data_size = 0;
+		kvfree(ue->tlv_data);
+	}
+
+	ue->tlv_data = container;
+	ue->tlv_data_size = size;
+	// decremented at private_free.
+	ue->card->user_ctl_alloc_size += size;
+
+	mask |= SNDRV_CTL_EVENT_MASK_TLV;
+	for (i = 0; i < kctl->count; ++i)
+		snd_ctl_notify_one(ue->card, mask, kctl, i);
+
+	return change;
+}
+
+static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
+			 unsigned int size)
+{
+	struct user_element *ue = kctl->private_data;
+
+	if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
+		return -ENXIO;
+
+	if (size < ue->tlv_data_size)
+		return -ENOSPC;
+
+	if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
+				 unsigned int size, unsigned int __user *buf)
+{
+	if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
+		return replace_user_tlv(kctl, buf, size);
+	else
+		return read_user_tlv(kctl, buf, size);
+}
+
+/* called in controls_rwsem write lock */
+static int snd_ctl_elem_init_enum_names(struct user_element *ue)
+{
+	char *names, *p;
+	size_t buf_len, name_len;
+	unsigned int i;
+	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
+
+	lockdep_assert_held_write(&ue->card->controls_rwsem);
+
+	buf_len = ue->info.value.enumerated.names_length;
+	if (buf_len > 64 * 1024)
+		return -EINVAL;
+
+	if (check_user_elem_overflow(ue->card, buf_len))
+		return -ENOMEM;
+	names = vmemdup_user((const void __user *)user_ptrval, buf_len);
+	if (IS_ERR(names))
+		return PTR_ERR(names);
+
+	/* check that there are enough valid names */
+	p = names;
+	for (i = 0; i < ue->info.value.enumerated.items; ++i) {
+		name_len = strnlen(p, buf_len);
+		if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
+			kvfree(names);
+			return -EINVAL;
+		}
+		p += name_len + 1;
+		buf_len -= name_len + 1;
+	}
+
+	ue->priv_data = names;
+	ue->info.value.enumerated.names_ptr = 0;
+	// increment the allocation size; decremented again at private_free.
+	ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length;
+
+	return 0;
+}
+
+static size_t compute_user_elem_size(size_t size, unsigned int count)
+{
+	return sizeof(struct user_element) + size * count;
+}
+
+static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
+{
+	struct user_element *ue = kcontrol->private_data;
+
+	// decrement the allocation size.
+	ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count);
+	ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
+	if (ue->priv_data)
+		ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length;
+
+	kvfree(ue->tlv_data);
+	kvfree(ue->priv_data);
+	kfree(ue);
+}
+
+static int snd_ctl_elem_add(struct snd_ctl_file *file,
+			    struct snd_ctl_elem_info *info, int replace)
+{
+	struct snd_card *card = file->card;
+	struct snd_kcontrol *kctl;
+	unsigned int count;
+	unsigned int access;
+	long private_size;
+	size_t alloc_size;
+	struct user_element *ue;
+	unsigned int offset;
+	int err;
+
+	if (!*info->id.name)
+		return -EINVAL;
+	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
+		return -EINVAL;
+
+	/* Delete a control to replace them if needed. */
+	if (replace) {
+		info->id.numid = 0;
+		err = snd_ctl_remove_user_ctl(file, &info->id);
+		if (err)
+			return err;
+	}
+
+	/* Check the number of elements for this userspace control. */
+	count = info->owner;
+	if (count == 0)
+		count = 1;
+
+	/* Arrange access permissions if needed. */
+	access = info->access;
+	if (access == 0)
+		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
+	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
+		   SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
+
+	/* In initial state, nothing is available as TLV container. */
+	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
+		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
+	access |= SNDRV_CTL_ELEM_ACCESS_USER;
+
+	/*
+	 * Check information and calculate the size of data specific to
+	 * this userspace control.
+	 */
+	/* pass NULL to card for suppressing error messages */
+	err = snd_ctl_check_elem_info(NULL, info);
+	if (err < 0)
+		return err;
+	/* user-space control doesn't allow zero-size data */
+	if (info->count < 1)
+		return -EINVAL;
+	private_size = value_sizes[info->type] * info->count;
+	alloc_size = compute_user_elem_size(private_size, count);
+
+	down_write(&card->controls_rwsem);
+	if (check_user_elem_overflow(card, alloc_size)) {
+		err = -ENOMEM;
+		goto unlock;
+	}
+
+	/*
+	 * Keep memory object for this userspace control. After passing this
+	 * code block, the instance should be freed by snd_ctl_free_one().
+	 *
+	 * Note that these elements in this control are locked.
+	 */
+	err = snd_ctl_new(&kctl, count, access, file);
+	if (err < 0)
+		goto unlock;
+	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
+	ue = kzalloc(alloc_size, GFP_KERNEL);
+	if (!ue) {
+		kfree(kctl);
+		err = -ENOMEM;
+		goto unlock;
+	}
+	kctl->private_data = ue;
+	kctl->private_free = snd_ctl_elem_user_free;
+
+	// increment the allocated size; decremented again at private_free.
+	card->user_ctl_alloc_size += alloc_size;
+
+	/* Set private data for this userspace control. */
+	ue->card = card;
+	ue->info = *info;
+	ue->info.access = 0;
+	ue->elem_data = (char *)ue + sizeof(*ue);
+	ue->elem_data_size = private_size;
+	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
+		err = snd_ctl_elem_init_enum_names(ue);
+		if (err < 0) {
+			snd_ctl_free_one(kctl);
+			goto unlock;
+		}
+	}
+
+	/* Set callback functions. */
+	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
+		kctl->info = snd_ctl_elem_user_enum_info;
+	else
+		kctl->info = snd_ctl_elem_user_info;
+	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
+		kctl->get = snd_ctl_elem_user_get;
+	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
+		kctl->put = snd_ctl_elem_user_put;
+	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
+		kctl->tlv.c = snd_ctl_elem_user_tlv;
+
+	/* This function manage to free the instance on failure. */
+	err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
+	if (err < 0) {
+		snd_ctl_free_one(kctl);
+		goto unlock;
+	}
+	offset = snd_ctl_get_ioff(kctl, &info->id);
+	snd_ctl_build_ioff(&info->id, kctl, offset);
+	/*
+	 * Here we cannot fill any field for the number of elements added by
+	 * this operation because there're no specific fields. The usage of
+	 * 'owner' field for this purpose may cause any bugs to userspace
+	 * applications because the field originally means PID of a process
+	 * which locks the element.
+	 */
+ unlock:
+	up_write(&card->controls_rwsem);
+	return err;
+}
+
+static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
+				 struct snd_ctl_elem_info __user *_info, int replace)
+{
+	struct snd_ctl_elem_info info;
+	int err;
+
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	err = snd_ctl_elem_add(file, &info, replace);
+	if (err < 0)
+		return err;
+	if (copy_to_user(_info, &info, sizeof(info))) {
+		snd_ctl_remove_user_ctl(file, &info.id);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static int snd_ctl_elem_remove(struct snd_ctl_file *file,
+			       struct snd_ctl_elem_id __user *_id)
+{
+	struct snd_ctl_elem_id id;
+
+	if (copy_from_user(&id, _id, sizeof(id)))
+		return -EFAULT;
+	return snd_ctl_remove_user_ctl(file, &id);
+}
+
+static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
+{
+	int subscribe;
+	if (get_user(subscribe, ptr))
+		return -EFAULT;
+	if (subscribe < 0) {
+		subscribe = file->subscribed;
+		if (put_user(subscribe, ptr))
+			return -EFAULT;
+		return 0;
+	}
+	if (subscribe) {
+		file->subscribed = 1;
+		return 0;
+	} else if (file->subscribed) {
+		snd_ctl_empty_read_queue(file);
+		file->subscribed = 0;
+	}
+	return 0;
+}
+
+static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
+			    struct snd_kcontrol *kctl,
+			    struct snd_ctl_elem_id *id,
+			    unsigned int __user *buf, unsigned int size)
+{
+	static const struct {
+		int op;
+		int perm;
+	} pairs[] = {
+		{SNDRV_CTL_TLV_OP_READ,  SNDRV_CTL_ELEM_ACCESS_TLV_READ},
+		{SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
+		{SNDRV_CTL_TLV_OP_CMD,   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
+	};
+	struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
+	int i, ret;
+
+	/* Check support of the request for this element. */
+	for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
+		if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
+			break;
+	}
+	if (i == ARRAY_SIZE(pairs))
+		return -ENXIO;
+
+	if (kctl->tlv.c == NULL)
+		return -ENXIO;
+
+	/* Write and command operations are not allowed for locked element. */
+	if (op_flag != SNDRV_CTL_TLV_OP_READ &&
+	    vd->owner != NULL && vd->owner != file)
+		return -EPERM;
+
+	ret = snd_power_ref_and_wait(file->card);
+	if (!ret)
+		ret = kctl->tlv.c(kctl, op_flag, size, buf);
+	snd_power_unref(file->card);
+	return ret;
+}
+
+static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
+			unsigned int __user *buf, unsigned int size)
+{
+	struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
+	unsigned int len;
+
+	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
+		return -ENXIO;
+
+	if (kctl->tlv.p == NULL)
+		return -ENXIO;
+
+	len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
+	if (size < len)
+		return -ENOMEM;
+
+	if (copy_to_user(buf, kctl->tlv.p, len))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
+			     struct snd_ctl_tlv __user *buf,
+                             int op_flag)
+{
+	struct snd_ctl_tlv header;
+	unsigned int __user *container;
+	unsigned int container_size;
+	struct snd_kcontrol *kctl;
+	struct snd_ctl_elem_id id;
+	struct snd_kcontrol_volatile *vd;
+
+	lockdep_assert_held(&file->card->controls_rwsem);
+
+	if (copy_from_user(&header, buf, sizeof(header)))
+		return -EFAULT;
+
+	/* In design of control core, numerical ID starts at 1. */
+	if (header.numid == 0)
+		return -EINVAL;
+
+	/* At least, container should include type and length fields.  */
+	if (header.length < sizeof(unsigned int) * 2)
+		return -EINVAL;
+	container_size = header.length;
+	container = buf->tlv;
+
+	kctl = snd_ctl_find_numid_locked(file->card, header.numid);
+	if (kctl == NULL)
+		return -ENOENT;
+
+	/* Calculate index of the element in this set. */
+	id = kctl->id;
+	snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
+	vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
+
+	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
+		return call_tlv_handler(file, op_flag, kctl, &id, container,
+					container_size);
+	} else {
+		if (op_flag == SNDRV_CTL_TLV_OP_READ) {
+			return read_tlv_buf(kctl, &id, container,
+					    container_size);
+		}
+	}
+
+	/* Not supported. */
+	return -ENXIO;
+}
+
+static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_ctl_file *ctl;
+	struct snd_card *card;
+	struct snd_kctl_ioctl *p;
+	void __user *argp = (void __user *)arg;
+	int __user *ip = argp;
+	int err;
+
+	ctl = file->private_data;
+	card = ctl->card;
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_PVERSION:
+		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
+	case SNDRV_CTL_IOCTL_CARD_INFO:
+		return snd_ctl_card_info(card, ctl, cmd, argp);
+	case SNDRV_CTL_IOCTL_ELEM_LIST:
+		return snd_ctl_elem_list_user(card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_INFO:
+		return snd_ctl_elem_info_user(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_READ:
+		return snd_ctl_elem_read_user(card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_WRITE:
+		return snd_ctl_elem_write_user(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_LOCK:
+		return snd_ctl_elem_lock(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
+		return snd_ctl_elem_unlock(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_ADD:
+		return snd_ctl_elem_add_user(ctl, argp, 0);
+	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
+		return snd_ctl_elem_add_user(ctl, argp, 1);
+	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
+		return snd_ctl_elem_remove(ctl, argp);
+	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
+		return snd_ctl_subscribe_events(ctl, ip);
+	case SNDRV_CTL_IOCTL_TLV_READ:
+		down_read(&ctl->card->controls_rwsem);
+		err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
+		up_read(&ctl->card->controls_rwsem);
+		return err;
+	case SNDRV_CTL_IOCTL_TLV_WRITE:
+		down_write(&ctl->card->controls_rwsem);
+		err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
+		up_write(&ctl->card->controls_rwsem);
+		return err;
+	case SNDRV_CTL_IOCTL_TLV_COMMAND:
+		down_write(&ctl->card->controls_rwsem);
+		err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
+		up_write(&ctl->card->controls_rwsem);
+		return err;
+	case SNDRV_CTL_IOCTL_POWER:
+		return -ENOPROTOOPT;
+	case SNDRV_CTL_IOCTL_POWER_STATE:
+		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
+	}
+	down_read(&snd_ioctl_rwsem);
+	list_for_each_entry(p, &snd_control_ioctls, list) {
+		err = p->fioctl(card, ctl, cmd, arg);
+		if (err != -ENOIOCTLCMD) {
+			up_read(&snd_ioctl_rwsem);
+			return err;
+		}
+	}
+	up_read(&snd_ioctl_rwsem);
+	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
+	return -ENOTTY;
+}
+
+static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
+			    size_t count, loff_t * offset)
+{
+	struct snd_ctl_file *ctl;
+	int err = 0;
+	ssize_t result = 0;
+
+	ctl = file->private_data;
+	if (snd_BUG_ON(!ctl || !ctl->card))
+		return -ENXIO;
+	if (!ctl->subscribed)
+		return -EBADFD;
+	if (count < sizeof(struct snd_ctl_event))
+		return -EINVAL;
+	spin_lock_irq(&ctl->read_lock);
+	while (count >= sizeof(struct snd_ctl_event)) {
+		struct snd_ctl_event ev;
+		struct snd_kctl_event *kev;
+		while (list_empty(&ctl->events)) {
+			wait_queue_entry_t wait;
+			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
+				err = -EAGAIN;
+				goto __end_lock;
+			}
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&ctl->change_sleep, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+			spin_unlock_irq(&ctl->read_lock);
+			schedule();
+			remove_wait_queue(&ctl->change_sleep, &wait);
+			if (ctl->card->shutdown)
+				return -ENODEV;
+			if (signal_pending(current))
+				return -ERESTARTSYS;
+			spin_lock_irq(&ctl->read_lock);
+		}
+		kev = snd_kctl_event(ctl->events.next);
+		ev.type = SNDRV_CTL_EVENT_ELEM;
+		ev.data.elem.mask = kev->mask;
+		ev.data.elem.id = kev->id;
+		list_del(&kev->list);
+		spin_unlock_irq(&ctl->read_lock);
+		kfree(kev);
+		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
+			err = -EFAULT;
+			goto __end;
+		}
+		spin_lock_irq(&ctl->read_lock);
+		buffer += sizeof(struct snd_ctl_event);
+		count -= sizeof(struct snd_ctl_event);
+		result += sizeof(struct snd_ctl_event);
+	}
+      __end_lock:
+	spin_unlock_irq(&ctl->read_lock);
+      __end:
+      	return result > 0 ? result : err;
+}
+
+static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
+{
+	__poll_t mask;
+	struct snd_ctl_file *ctl;
+
+	ctl = file->private_data;
+	if (!ctl->subscribed)
+		return 0;
+	poll_wait(file, &ctl->change_sleep, wait);
+
+	mask = 0;
+	if (!list_empty(&ctl->events))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	return mask;
+}
+
+/*
+ * register the device-specific control-ioctls.
+ * called from each device manager like pcm.c, hwdep.c, etc.
+ */
+static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
+{
+	struct snd_kctl_ioctl *pn;
+
+	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
+	if (pn == NULL)
+		return -ENOMEM;
+	pn->fioctl = fcn;
+	down_write(&snd_ioctl_rwsem);
+	list_add_tail(&pn->list, lists);
+	up_write(&snd_ioctl_rwsem);
+	return 0;
+}
+
+/**
+ * snd_ctl_register_ioctl - register the device-specific control-ioctls
+ * @fcn: ioctl callback function
+ *
+ * called from each device manager like pcm.c, hwdep.c, etc.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
+}
+EXPORT_SYMBOL(snd_ctl_register_ioctl);
+
+#ifdef CONFIG_COMPAT
+/**
+ * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
+ * control-ioctls
+ * @fcn: ioctl callback function
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
+}
+EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
+#endif
+
+/*
+ * de-register the device-specific control-ioctls.
+ */
+static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
+				     struct list_head *lists)
+{
+	struct snd_kctl_ioctl *p;
+
+	if (snd_BUG_ON(!fcn))
+		return -EINVAL;
+	down_write(&snd_ioctl_rwsem);
+	list_for_each_entry(p, lists, list) {
+		if (p->fioctl == fcn) {
+			list_del(&p->list);
+			up_write(&snd_ioctl_rwsem);
+			kfree(p);
+			return 0;
+		}
+	}
+	up_write(&snd_ioctl_rwsem);
+	snd_BUG();
+	return -EINVAL;
+}
+
+/**
+ * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
+ * @fcn: ioctl callback function to unregister
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
+}
+EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
+
+#ifdef CONFIG_COMPAT
+/**
+ * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat
+ * 32bit control-ioctls
+ * @fcn: ioctl callback function to unregister
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
+}
+EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
+#endif
+
+static int snd_ctl_fasync(int fd, struct file * file, int on)
+{
+	struct snd_ctl_file *ctl;
+
+	ctl = file->private_data;
+	return snd_fasync_helper(fd, file, on, &ctl->fasync);
+}
+
+/* return the preferred subdevice number if already assigned;
+ * otherwise return -1
+ */
+int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
+{
+	struct snd_ctl_file *kctl;
+	int subdevice = -1;
+	unsigned long flags;
+
+	read_lock_irqsave(&card->ctl_files_rwlock, flags);
+	list_for_each_entry(kctl, &card->ctl_files, list) {
+		if (kctl->pid == task_pid(current)) {
+			subdevice = kctl->preferred_subdevice[type];
+			if (subdevice != -1)
+				break;
+		}
+	}
+	read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+	return subdevice;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
+
+/*
+ * ioctl32 compat
+ */
+#ifdef CONFIG_COMPAT
+#include "control_compat.c"
+#else
+#define snd_ctl_ioctl_compat	NULL
+#endif
+
+/*
+ * control layers (audio LED etc.)
+ */
+
+/**
+ * snd_ctl_request_layer - request to use the layer
+ * @module_name: Name of the kernel module (NULL == build-in)
+ *
+ * Return: zero if successful, or an error code when the module cannot be loaded
+ */
+int snd_ctl_request_layer(const char *module_name)
+{
+	struct snd_ctl_layer_ops *lops;
+
+	if (module_name == NULL)
+		return 0;
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		if (strcmp(lops->module_name, module_name) == 0)
+			break;
+	up_read(&snd_ctl_layer_rwsem);
+	if (lops)
+		return 0;
+	return request_module(module_name);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_request_layer);
+
+/**
+ * snd_ctl_register_layer - register new control layer
+ * @lops: operation structure
+ *
+ * The new layer can track all control elements and do additional
+ * operations on top (like audio LED handling).
+ */
+void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
+{
+	struct snd_card *card;
+	int card_number;
+
+	down_write(&snd_ctl_layer_rwsem);
+	lops->next = snd_ctl_layer;
+	snd_ctl_layer = lops;
+	up_write(&snd_ctl_layer_rwsem);
+	for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
+		card = snd_card_ref(card_number);
+		if (card) {
+			down_read(&card->controls_rwsem);
+			lops->lregister(card);
+			up_read(&card->controls_rwsem);
+			snd_card_unref(card);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(snd_ctl_register_layer);
+
+/**
+ * snd_ctl_disconnect_layer - disconnect control layer
+ * @lops: operation structure
+ *
+ * It is expected that the information about tracked cards
+ * is freed before this call (the disconnect callback is
+ * not called here).
+ */
+void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
+{
+	struct snd_ctl_layer_ops *lops2, *prev_lops2;
+
+	down_write(&snd_ctl_layer_rwsem);
+	for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) {
+		if (lops2 == lops) {
+			if (!prev_lops2)
+				snd_ctl_layer = lops->next;
+			else
+				prev_lops2->next = lops->next;
+			break;
+		}
+		prev_lops2 = lops2;
+	}
+	up_write(&snd_ctl_layer_rwsem);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
+
+/*
+ *  INIT PART
+ */
+
+static const struct file_operations snd_ctl_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.read =		snd_ctl_read,
+	.open =		snd_ctl_open,
+	.release =	snd_ctl_release,
+	.llseek =	no_llseek,
+	.poll =		snd_ctl_poll,
+	.unlocked_ioctl =	snd_ctl_ioctl,
+	.compat_ioctl =	snd_ctl_ioctl_compat,
+	.fasync =	snd_ctl_fasync,
+};
+
+/*
+ * registration of the control device
+ */
+static int snd_ctl_dev_register(struct snd_device *device)
+{
+	struct snd_card *card = device->device_data;
+	struct snd_ctl_layer_ops *lops;
+	int err;
+
+	err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
+				  &snd_ctl_f_ops, card, card->ctl_dev);
+	if (err < 0)
+		return err;
+	down_read(&card->controls_rwsem);
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		lops->lregister(card);
+	up_read(&snd_ctl_layer_rwsem);
+	up_read(&card->controls_rwsem);
+	return 0;
+}
+
+/*
+ * disconnection of the control device
+ */
+static int snd_ctl_dev_disconnect(struct snd_device *device)
+{
+	struct snd_card *card = device->device_data;
+	struct snd_ctl_file *ctl;
+	struct snd_ctl_layer_ops *lops;
+	unsigned long flags;
+
+	read_lock_irqsave(&card->ctl_files_rwlock, flags);
+	list_for_each_entry(ctl, &card->ctl_files, list) {
+		wake_up(&ctl->change_sleep);
+		snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR);
+	}
+	read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+
+	down_read(&card->controls_rwsem);
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		lops->ldisconnect(card);
+	up_read(&snd_ctl_layer_rwsem);
+	up_read(&card->controls_rwsem);
+
+	return snd_unregister_device(card->ctl_dev);
+}
+
+/*
+ * free all controls
+ */
+static int snd_ctl_dev_free(struct snd_device *device)
+{
+	struct snd_card *card = device->device_data;
+	struct snd_kcontrol *control;
+
+	down_write(&card->controls_rwsem);
+	while (!list_empty(&card->controls)) {
+		control = snd_kcontrol(card->controls.next);
+		__snd_ctl_remove(card, control, false);
+	}
+
+#ifdef CONFIG_SND_CTL_FAST_LOOKUP
+	xa_destroy(&card->ctl_numids);
+	xa_destroy(&card->ctl_hash);
+#endif
+	up_write(&card->controls_rwsem);
+	put_device(card->ctl_dev);
+	return 0;
+}
+
+/*
+ * create control core:
+ * called from init.c
+ */
+int snd_ctl_create(struct snd_card *card)
+{
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_ctl_dev_free,
+		.dev_register =	snd_ctl_dev_register,
+		.dev_disconnect = snd_ctl_dev_disconnect,
+	};
+	int err;
+
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+	if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
+		return -ENXIO;
+
+	err = snd_device_alloc(&card->ctl_dev, card);
+	if (err < 0)
+		return err;
+	dev_set_name(card->ctl_dev, "controlC%d", card->number);
+
+	err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
+	if (err < 0)
+		put_device(card->ctl_dev);
+	return err;
+}
+
+/*
+ * Frequently used control callbacks/helpers
+ */
+
+/**
+ * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
+ * callback with a mono channel
+ * @kcontrol: the kcontrol instance
+ * @uinfo: info to store
+ *
+ * This is a function that can be used as info callback for a standard
+ * boolean control with a single mono channel.
+ *
+ * Return: Zero (always successful)
+ */
+int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	return 0;
+}
+EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
+
+/**
+ * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
+ * callback with stereo two channels
+ * @kcontrol: the kcontrol instance
+ * @uinfo: info to store
+ *
+ * This is a function that can be used as info callback for a standard
+ * boolean control with stereo two channels.
+ *
+ * Return: Zero (always successful)
+ */
+int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = 2;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	return 0;
+}
+EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
+
+/**
+ * snd_ctl_enum_info - fills the info structure for an enumerated control
+ * @info: the structure to be filled
+ * @channels: the number of the control's channels; often one
+ * @items: the number of control values; also the size of @names
+ * @names: an array containing the names of all control values
+ *
+ * Sets all required fields in @info to their appropriate values.
+ * If the control's accessibility is not the default (readable and writable),
+ * the caller has to fill @info->access.
+ *
+ * Return: Zero (always successful)
+ */
+int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
+		      unsigned int items, const char *const names[])
+{
+	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
+	info->count = channels;
+	info->value.enumerated.items = items;
+	if (!items)
+		return 0;
+	if (info->value.enumerated.item >= items)
+		info->value.enumerated.item = items - 1;
+	WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
+	     "ALSA: too long item name '%s'\n",
+	     names[info->value.enumerated.item]);
+	strscpy(info->value.enumerated.name,
+		names[info->value.enumerated.item],
+		sizeof(info->value.enumerated.name));
+	return 0;
+}
+EXPORT_SYMBOL(snd_ctl_enum_info);
diff --git a/sound/core/control_compat.c b/sound/core/control_compat.c
new file mode 100644
index 0000000000..0e8b1bfb04
--- /dev/null
+++ b/sound/core/control_compat.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * compat ioctls for control API
+ *
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ */
+
+/* this file included from control.c */
+
+#include <linux/compat.h>
+#include <linux/slab.h>
+
+struct snd_ctl_elem_list32 {
+	u32 offset;
+	u32 space;
+	u32 used;
+	u32 count;
+	u32 pids;
+	unsigned char reserved[50];
+} /* don't set packed attribute here */;
+
+static int snd_ctl_elem_list_compat(struct snd_card *card,
+				    struct snd_ctl_elem_list32 __user *data32)
+{
+	struct snd_ctl_elem_list data = {};
+	compat_caddr_t ptr;
+	int err;
+
+	/* offset, space, used, count */
+	if (copy_from_user(&data, data32, 4 * sizeof(u32)))
+		return -EFAULT;
+	/* pids */
+	if (get_user(ptr, &data32->pids))
+		return -EFAULT;
+	data.pids = compat_ptr(ptr);
+	err = snd_ctl_elem_list(card, &data);
+	if (err < 0)
+		return err;
+	/* copy the result */
+	if (copy_to_user(data32, &data, 4 * sizeof(u32)))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * control element info
+ * it uses union, so the things are not easy..
+ */
+
+struct snd_ctl_elem_info32 {
+	struct snd_ctl_elem_id id; // the size of struct is same
+	s32 type;
+	u32 access;
+	u32 count;
+	s32 owner;
+	union {
+		struct {
+			s32 min;
+			s32 max;
+			s32 step;
+		} integer;
+		struct {
+			u64 min;
+			u64 max;
+			u64 step;
+		} integer64;
+		struct {
+			u32 items;
+			u32 item;
+			char name[64];
+			u64 names_ptr;
+			u32 names_length;
+		} enumerated;
+		unsigned char reserved[128];
+	} value;
+	unsigned char reserved[64];
+} __attribute__((packed));
+
+static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
+				    struct snd_ctl_elem_info32 __user *data32)
+{
+	struct snd_ctl_elem_info *data;
+	int err;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (! data)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	/* copy id */
+	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
+		goto error;
+	/* we need to copy the item index.
+	 * hope this doesn't break anything..
+	 */
+	if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
+		goto error;
+
+	err = snd_ctl_elem_info(ctl, data);
+	if (err < 0)
+		goto error;
+	/* restore info to 32bit */
+	err = -EFAULT;
+	/* id, type, access, count */
+	if (copy_to_user(&data32->id, &data->id, sizeof(data->id)) ||
+	    copy_to_user(&data32->type, &data->type, 3 * sizeof(u32)))
+		goto error;
+	if (put_user(data->owner, &data32->owner))
+		goto error;
+	switch (data->type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		if (put_user(data->value.integer.min, &data32->value.integer.min) ||
+		    put_user(data->value.integer.max, &data32->value.integer.max) ||
+		    put_user(data->value.integer.step, &data32->value.integer.step))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		if (copy_to_user(&data32->value.integer64,
+				 &data->value.integer64,
+				 sizeof(data->value.integer64)))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		if (copy_to_user(&data32->value.enumerated,
+				 &data->value.enumerated,
+				 sizeof(data->value.enumerated)))
+			goto error;
+		break;
+	default:
+		break;
+	}
+	err = 0;
+ error:
+	kfree(data);
+	return err;
+}
+
+/* read / write */
+struct snd_ctl_elem_value32 {
+	struct snd_ctl_elem_id id;
+	unsigned int indirect;	/* bit-field causes misalignment */
+        union {
+		s32 integer[128];
+		unsigned char data[512];
+#ifndef CONFIG_X86_64
+		s64 integer64[64];
+#endif
+        } value;
+        unsigned char reserved[128];
+};
+
+#ifdef CONFIG_X86_X32_ABI
+/* x32 has a different alignment for 64bit values from ia32 */
+struct snd_ctl_elem_value_x32 {
+	struct snd_ctl_elem_id id;
+	unsigned int indirect;	/* bit-field causes misalignment */
+	union {
+		s32 integer[128];
+		unsigned char data[512];
+		s64 integer64[64];
+	} value;
+	unsigned char reserved[128];
+};
+#endif /* CONFIG_X86_X32_ABI */
+
+/* get the value type and count of the control */
+static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
+			int *countp)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_ctl_elem_info *info;
+	int err;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id_locked(card, id);
+	if (! kctl) {
+		up_read(&card->controls_rwsem);
+		return -ENOENT;
+	}
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (info == NULL) {
+		up_read(&card->controls_rwsem);
+		return -ENOMEM;
+	}
+	info->id = *id;
+	err = snd_power_ref_and_wait(card);
+	if (!err)
+		err = kctl->info(kctl, info);
+	snd_power_unref(card);
+	up_read(&card->controls_rwsem);
+	if (err >= 0) {
+		err = info->type;
+		*countp = info->count;
+	}
+	kfree(info);
+	return err;
+}
+
+static int get_elem_size(snd_ctl_elem_type_t type, int count)
+{
+	switch (type) {
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		return sizeof(s64) * count;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		return sizeof(int) * count;
+	case SNDRV_CTL_ELEM_TYPE_BYTES:
+		return 512;
+	case SNDRV_CTL_ELEM_TYPE_IEC958:
+		return sizeof(struct snd_aes_iec958);
+	default:
+		return -1;
+	}
+}
+
+static int copy_ctl_value_from_user(struct snd_card *card,
+				    struct snd_ctl_elem_value *data,
+				    void __user *userdata,
+				    void __user *valuep,
+				    int *typep, int *countp)
+{
+	struct snd_ctl_elem_value32 __user *data32 = userdata;
+	int i, type, size;
+	int count;
+	unsigned int indirect;
+
+	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
+		return -EFAULT;
+	if (get_user(indirect, &data32->indirect))
+		return -EFAULT;
+	if (indirect)
+		return -EINVAL;
+	type = get_ctl_type(card, &data->id, &count);
+	if (type < 0)
+		return type;
+
+	if (type == (__force int)SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    type == (__force int)SNDRV_CTL_ELEM_TYPE_INTEGER) {
+		for (i = 0; i < count; i++) {
+			s32 __user *intp = valuep;
+			int val;
+			if (get_user(val, &intp[i]))
+				return -EFAULT;
+			data->value.integer.value[i] = val;
+		}
+	} else {
+		size = get_elem_size((__force snd_ctl_elem_type_t)type, count);
+		if (size < 0) {
+			dev_err(card->dev, "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
+			return -EINVAL;
+		}
+		if (copy_from_user(data->value.bytes.data, valuep, size))
+			return -EFAULT;
+	}
+
+	*typep = type;
+	*countp = count;
+	return 0;
+}
+
+/* restore the value to 32bit */
+static int copy_ctl_value_to_user(void __user *userdata,
+				  void __user *valuep,
+				  struct snd_ctl_elem_value *data,
+				  int type, int count)
+{
+	struct snd_ctl_elem_value32 __user *data32 = userdata;
+	int i, size;
+
+	if (type == (__force int)SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    type == (__force int)SNDRV_CTL_ELEM_TYPE_INTEGER) {
+		for (i = 0; i < count; i++) {
+			s32 __user *intp = valuep;
+			int val;
+			val = data->value.integer.value[i];
+			if (put_user(val, &intp[i]))
+				return -EFAULT;
+		}
+	} else {
+		size = get_elem_size((__force snd_ctl_elem_type_t)type, count);
+		if (copy_to_user(valuep, data->value.bytes.data, size))
+			return -EFAULT;
+	}
+	if (copy_to_user(&data32->id, &data->id, sizeof(data32->id)))
+		return -EFAULT;
+	return 0;
+}
+
+static int ctl_elem_read_user(struct snd_card *card,
+			      void __user *userdata, void __user *valuep)
+{
+	struct snd_ctl_elem_value *data;
+	int err, type, count;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	err = copy_ctl_value_from_user(card, data, userdata, valuep,
+				       &type, &count);
+	if (err < 0)
+		goto error;
+
+	err = snd_ctl_elem_read(card, data);
+	if (err < 0)
+		goto error;
+	err = copy_ctl_value_to_user(userdata, valuep, data, type, count);
+ error:
+	kfree(data);
+	return err;
+}
+
+static int ctl_elem_write_user(struct snd_ctl_file *file,
+			       void __user *userdata, void __user *valuep)
+{
+	struct snd_ctl_elem_value *data;
+	struct snd_card *card = file->card;
+	int err, type, count;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	err = copy_ctl_value_from_user(card, data, userdata, valuep,
+				       &type, &count);
+	if (err < 0)
+		goto error;
+
+	err = snd_ctl_elem_write(card, file, data);
+	if (err < 0)
+		goto error;
+	err = copy_ctl_value_to_user(userdata, valuep, data, type, count);
+ error:
+	kfree(data);
+	return err;
+}
+
+static int snd_ctl_elem_read_user_compat(struct snd_card *card,
+					 struct snd_ctl_elem_value32 __user *data32)
+{
+	return ctl_elem_read_user(card, data32, &data32->value);
+}
+
+static int snd_ctl_elem_write_user_compat(struct snd_ctl_file *file,
+					  struct snd_ctl_elem_value32 __user *data32)
+{
+	return ctl_elem_write_user(file, data32, &data32->value);
+}
+
+#ifdef CONFIG_X86_X32_ABI
+static int snd_ctl_elem_read_user_x32(struct snd_card *card,
+				      struct snd_ctl_elem_value_x32 __user *data32)
+{
+	return ctl_elem_read_user(card, data32, &data32->value);
+}
+
+static int snd_ctl_elem_write_user_x32(struct snd_ctl_file *file,
+				       struct snd_ctl_elem_value_x32 __user *data32)
+{
+	return ctl_elem_write_user(file, data32, &data32->value);
+}
+#endif /* CONFIG_X86_X32_ABI */
+
+/* add or replace a user control */
+static int snd_ctl_elem_add_compat(struct snd_ctl_file *file,
+				   struct snd_ctl_elem_info32 __user *data32,
+				   int replace)
+{
+	struct snd_ctl_elem_info *data;
+	int err;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (! data)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	/* id, type, access, count */ \
+	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)) ||
+	    copy_from_user(&data->type, &data32->type, 3 * sizeof(u32)))
+		goto error;
+	if (get_user(data->owner, &data32->owner))
+		goto error;
+	switch (data->type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		if (get_user(data->value.integer.min, &data32->value.integer.min) ||
+		    get_user(data->value.integer.max, &data32->value.integer.max) ||
+		    get_user(data->value.integer.step, &data32->value.integer.step))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		if (copy_from_user(&data->value.integer64,
+				   &data32->value.integer64,
+				   sizeof(data->value.integer64)))
+			goto error;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		if (copy_from_user(&data->value.enumerated,
+				   &data32->value.enumerated,
+				   sizeof(data->value.enumerated)))
+			goto error;
+		data->value.enumerated.names_ptr =
+			(uintptr_t)compat_ptr(data->value.enumerated.names_ptr);
+		break;
+	default:
+		break;
+	}
+	err = snd_ctl_elem_add(file, data, replace);
+ error:
+	kfree(data);
+	return err;
+}  
+
+enum {
+	SNDRV_CTL_IOCTL_ELEM_LIST32 = _IOWR('U', 0x10, struct snd_ctl_elem_list32),
+	SNDRV_CTL_IOCTL_ELEM_INFO32 = _IOWR('U', 0x11, struct snd_ctl_elem_info32),
+	SNDRV_CTL_IOCTL_ELEM_READ32 = _IOWR('U', 0x12, struct snd_ctl_elem_value32),
+	SNDRV_CTL_IOCTL_ELEM_WRITE32 = _IOWR('U', 0x13, struct snd_ctl_elem_value32),
+	SNDRV_CTL_IOCTL_ELEM_ADD32 = _IOWR('U', 0x17, struct snd_ctl_elem_info32),
+	SNDRV_CTL_IOCTL_ELEM_REPLACE32 = _IOWR('U', 0x18, struct snd_ctl_elem_info32),
+#ifdef CONFIG_X86_X32_ABI
+	SNDRV_CTL_IOCTL_ELEM_READ_X32 = _IOWR('U', 0x12, struct snd_ctl_elem_value_x32),
+	SNDRV_CTL_IOCTL_ELEM_WRITE_X32 = _IOWR('U', 0x13, struct snd_ctl_elem_value_x32),
+#endif /* CONFIG_X86_X32_ABI */
+};
+
+static inline long snd_ctl_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_ctl_file *ctl;
+	struct snd_kctl_ioctl *p;
+	void __user *argp = compat_ptr(arg);
+	int err;
+
+	ctl = file->private_data;
+	if (snd_BUG_ON(!ctl || !ctl->card))
+		return -ENXIO;
+
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_PVERSION:
+	case SNDRV_CTL_IOCTL_CARD_INFO:
+	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
+	case SNDRV_CTL_IOCTL_POWER:
+	case SNDRV_CTL_IOCTL_POWER_STATE:
+	case SNDRV_CTL_IOCTL_ELEM_LOCK:
+	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
+	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
+	case SNDRV_CTL_IOCTL_TLV_READ:
+	case SNDRV_CTL_IOCTL_TLV_WRITE:
+	case SNDRV_CTL_IOCTL_TLV_COMMAND:
+		return snd_ctl_ioctl(file, cmd, (unsigned long)argp);
+	case SNDRV_CTL_IOCTL_ELEM_LIST32:
+		return snd_ctl_elem_list_compat(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_INFO32:
+		return snd_ctl_elem_info_compat(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_READ32:
+		return snd_ctl_elem_read_user_compat(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_WRITE32:
+		return snd_ctl_elem_write_user_compat(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_ADD32:
+		return snd_ctl_elem_add_compat(ctl, argp, 0);
+	case SNDRV_CTL_IOCTL_ELEM_REPLACE32:
+		return snd_ctl_elem_add_compat(ctl, argp, 1);
+#ifdef CONFIG_X86_X32_ABI
+	case SNDRV_CTL_IOCTL_ELEM_READ_X32:
+		return snd_ctl_elem_read_user_x32(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_WRITE_X32:
+		return snd_ctl_elem_write_user_x32(ctl, argp);
+#endif /* CONFIG_X86_X32_ABI */
+	}
+
+	down_read(&snd_ioctl_rwsem);
+	list_for_each_entry(p, &snd_control_compat_ioctls, list) {
+		if (p->fioctl) {
+			err = p->fioctl(ctl->card, ctl, cmd, arg);
+			if (err != -ENOIOCTLCMD) {
+				up_read(&snd_ioctl_rwsem);
+				return err;
+			}
+		}
+	}
+	up_read(&snd_ioctl_rwsem);
+	return -ENOIOCTLCMD;
+}
diff --git a/sound/core/control_led.c b/sound/core/control_led.c
new file mode 100644
index 0000000000..a78eb48927
--- /dev/null
+++ b/sound/core/control_led.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  LED state routines for driver control interface
+ *  Copyright (c) 2021 by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/leds.h>
+#include <sound/core.h>
+#include <sound/control.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("ALSA control interface to LED trigger code.");
+MODULE_LICENSE("GPL");
+
+#define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \
+			>> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1)
+
+#define to_led_card_dev(_dev) \
+	container_of(_dev, struct snd_ctl_led_card, dev)
+
+enum snd_ctl_led_mode {
+	 MODE_FOLLOW_MUTE = 0,
+	 MODE_FOLLOW_ROUTE,
+	 MODE_OFF,
+	 MODE_ON,
+};
+
+struct snd_ctl_led_card {
+	struct device dev;
+	int number;
+	struct snd_ctl_led *led;
+};
+
+struct snd_ctl_led {
+	struct device dev;
+	struct list_head controls;
+	const char *name;
+	unsigned int group;
+	enum led_audio trigger_type;
+	enum snd_ctl_led_mode mode;
+	struct snd_ctl_led_card *cards[SNDRV_CARDS];
+};
+
+struct snd_ctl_led_ctl {
+	struct list_head list;
+	struct snd_card *card;
+	unsigned int access;
+	struct snd_kcontrol *kctl;
+	unsigned int index_offset;
+};
+
+static DEFINE_MUTEX(snd_ctl_led_mutex);
+static bool snd_ctl_led_card_valid[SNDRV_CARDS];
+static struct snd_ctl_led snd_ctl_leds[MAX_LED] = {
+	{
+		.name = "speaker",
+		.group = (SNDRV_CTL_ELEM_ACCESS_SPK_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
+		.trigger_type = LED_AUDIO_MUTE,
+		.mode = MODE_FOLLOW_MUTE,
+	},
+	{
+		.name = "mic",
+		.group = (SNDRV_CTL_ELEM_ACCESS_MIC_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
+		.trigger_type = LED_AUDIO_MICMUTE,
+		.mode = MODE_FOLLOW_MUTE,
+	},
+};
+
+static void snd_ctl_led_sysfs_add(struct snd_card *card);
+static void snd_ctl_led_sysfs_remove(struct snd_card *card);
+
+#define UPDATE_ROUTE(route, cb) \
+	do { \
+		int route2 = (cb); \
+		if (route2 >= 0) \
+			route = route < 0 ? route2 : (route | route2); \
+	} while (0)
+
+static inline unsigned int access_to_group(unsigned int access)
+{
+	return ((access & SNDRV_CTL_ELEM_ACCESS_LED_MASK) >>
+				SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1;
+}
+
+static inline unsigned int group_to_access(unsigned int group)
+{
+	return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
+}
+
+static struct snd_ctl_led *snd_ctl_led_get_by_access(unsigned int access)
+{
+	unsigned int group = access_to_group(access);
+	if (group >= MAX_LED)
+		return NULL;
+	return &snd_ctl_leds[group];
+}
+
+/*
+ * A note for callers:
+ *   The two static variables info and value are protected using snd_ctl_led_mutex.
+ */
+static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
+{
+	static struct snd_ctl_elem_info info;
+	static struct snd_ctl_elem_value value;
+	struct snd_kcontrol *kctl = lctl->kctl;
+	unsigned int i;
+	int result;
+
+	memset(&info, 0, sizeof(info));
+	info.id = kctl->id;
+	info.id.index += lctl->index_offset;
+	info.id.numid += lctl->index_offset;
+	result = kctl->info(kctl, &info);
+	if (result < 0)
+		return -1;
+	memset(&value, 0, sizeof(value));
+	value.id = info.id;
+	result = kctl->get(kctl, &value);
+	if (result < 0)
+		return -1;
+	if (info.type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    info.type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
+		for (i = 0; i < info.count; i++)
+			if (value.value.integer.value[i] != info.value.integer.min)
+				return 1;
+	} else if (info.type == SNDRV_CTL_ELEM_TYPE_INTEGER64) {
+		for (i = 0; i < info.count; i++)
+			if (value.value.integer64.value[i] != info.value.integer64.min)
+				return 1;
+	}
+	return 0;
+}
+
+static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
+				  struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct snd_ctl_led *led;
+	struct snd_ctl_led_ctl *lctl;
+	int route;
+	bool found;
+
+	led = snd_ctl_led_get_by_access(access);
+	if (!led)
+		return;
+	route = -1;
+	found = false;
+	mutex_lock(&snd_ctl_led_mutex);
+	/* the card may not be registered (active) at this point */
+	if (card && !snd_ctl_led_card_valid[card->number]) {
+		mutex_unlock(&snd_ctl_led_mutex);
+		return;
+	}
+	list_for_each_entry(lctl, &led->controls, list) {
+		if (lctl->kctl == kctl && lctl->index_offset == ioff)
+			found = true;
+		UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
+	}
+	if (!found && kctl && card) {
+		lctl = kzalloc(sizeof(*lctl), GFP_KERNEL);
+		if (lctl) {
+			lctl->card = card;
+			lctl->access = access;
+			lctl->kctl = kctl;
+			lctl->index_offset = ioff;
+			list_add(&lctl->list, &led->controls);
+			UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
+		}
+	}
+	mutex_unlock(&snd_ctl_led_mutex);
+	switch (led->mode) {
+	case MODE_OFF:		route = 1; break;
+	case MODE_ON:		route = 0; break;
+	case MODE_FOLLOW_ROUTE:	if (route >= 0) route ^= 1; break;
+	case MODE_FOLLOW_MUTE:	/* noop */ break;
+	}
+	if (route >= 0)
+		ledtrig_audio_set(led->trigger_type, route ? LED_OFF : LED_ON);
+}
+
+static struct snd_ctl_led_ctl *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct list_head *controls;
+	struct snd_ctl_led_ctl *lctl;
+	unsigned int group;
+
+	for (group = 0; group < MAX_LED; group++) {
+		controls = &snd_ctl_leds[group].controls;
+		list_for_each_entry(lctl, controls, list)
+			if (lctl->kctl == kctl && lctl->index_offset == ioff)
+				return lctl;
+	}
+	return NULL;
+}
+
+static unsigned int snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff,
+				       unsigned int access)
+{
+	struct snd_ctl_led_ctl *lctl;
+	unsigned int ret = 0;
+
+	mutex_lock(&snd_ctl_led_mutex);
+	lctl = snd_ctl_led_find(kctl, ioff);
+	if (lctl && (access == 0 || access != lctl->access)) {
+		ret = lctl->access;
+		list_del(&lctl->list);
+		kfree(lctl);
+	}
+	mutex_unlock(&snd_ctl_led_mutex);
+	return ret;
+}
+
+static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask,
+			       struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct snd_kcontrol_volatile *vd;
+	unsigned int access, access2;
+
+	if (mask == SNDRV_CTL_EVENT_MASK_REMOVE) {
+		access = snd_ctl_led_remove(kctl, ioff, 0);
+		if (access)
+			snd_ctl_led_set_state(card, access, NULL, 0);
+	} else if (mask & SNDRV_CTL_EVENT_MASK_INFO) {
+		vd = &kctl->vd[ioff];
+		access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
+		access2 = snd_ctl_led_remove(kctl, ioff, access);
+		if (access2)
+			snd_ctl_led_set_state(card, access2, NULL, 0);
+		if (access)
+			snd_ctl_led_set_state(card, access, kctl, ioff);
+	} else if ((mask & (SNDRV_CTL_EVENT_MASK_ADD |
+			    SNDRV_CTL_EVENT_MASK_VALUE)) != 0) {
+		vd = &kctl->vd[ioff];
+		access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
+		if (access)
+			snd_ctl_led_set_state(card, access, kctl, ioff);
+	}
+}
+
+static int snd_ctl_led_set_id(int card_number, struct snd_ctl_elem_id *id,
+			      unsigned int group, bool set)
+{
+	struct snd_card *card;
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_volatile *vd;
+	unsigned int ioff, access, new_access;
+	int err = 0;
+
+	card = snd_card_ref(card_number);
+	if (card) {
+		down_write(&card->controls_rwsem);
+		kctl = snd_ctl_find_id_locked(card, id);
+		if (kctl) {
+			ioff = snd_ctl_get_ioff(kctl, id);
+			vd = &kctl->vd[ioff];
+			access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
+			if (access != 0 && access != group_to_access(group)) {
+				err = -EXDEV;
+				goto unlock;
+			}
+			new_access = vd->access & ~SNDRV_CTL_ELEM_ACCESS_LED_MASK;
+			if (set)
+				new_access |= group_to_access(group);
+			if (new_access != vd->access) {
+				vd->access = new_access;
+				snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, ioff);
+			}
+		} else {
+			err = -ENOENT;
+		}
+unlock:
+		up_write(&card->controls_rwsem);
+		snd_card_unref(card);
+	} else {
+		err = -ENXIO;
+	}
+	return err;
+}
+
+static void snd_ctl_led_refresh(void)
+{
+	unsigned int group;
+
+	for (group = 0; group < MAX_LED; group++)
+		snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
+}
+
+static void snd_ctl_led_ctl_destroy(struct snd_ctl_led_ctl *lctl)
+{
+	list_del(&lctl->list);
+	kfree(lctl);
+}
+
+static void snd_ctl_led_clean(struct snd_card *card)
+{
+	unsigned int group;
+	struct snd_ctl_led *led;
+	struct snd_ctl_led_ctl *lctl;
+
+	for (group = 0; group < MAX_LED; group++) {
+		led = &snd_ctl_leds[group];
+repeat:
+		list_for_each_entry(lctl, &led->controls, list)
+			if (!card || lctl->card == card) {
+				snd_ctl_led_ctl_destroy(lctl);
+				goto repeat;
+			}
+	}
+}
+
+static int snd_ctl_led_reset(int card_number, unsigned int group)
+{
+	struct snd_card *card;
+	struct snd_ctl_led *led;
+	struct snd_ctl_led_ctl *lctl;
+	struct snd_kcontrol_volatile *vd;
+	bool change = false;
+
+	card = snd_card_ref(card_number);
+	if (!card)
+		return -ENXIO;
+
+	mutex_lock(&snd_ctl_led_mutex);
+	if (!snd_ctl_led_card_valid[card_number]) {
+		mutex_unlock(&snd_ctl_led_mutex);
+		snd_card_unref(card);
+		return -ENXIO;
+	}
+	led = &snd_ctl_leds[group];
+repeat:
+	list_for_each_entry(lctl, &led->controls, list)
+		if (lctl->card == card) {
+			vd = &lctl->kctl->vd[lctl->index_offset];
+			vd->access &= ~group_to_access(group);
+			snd_ctl_led_ctl_destroy(lctl);
+			change = true;
+			goto repeat;
+		}
+	mutex_unlock(&snd_ctl_led_mutex);
+	if (change)
+		snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
+	snd_card_unref(card);
+	return 0;
+}
+
+static void snd_ctl_led_register(struct snd_card *card)
+{
+	struct snd_kcontrol *kctl;
+	unsigned int ioff;
+
+	if (snd_BUG_ON(card->number < 0 ||
+		       card->number >= ARRAY_SIZE(snd_ctl_led_card_valid)))
+		return;
+	mutex_lock(&snd_ctl_led_mutex);
+	snd_ctl_led_card_valid[card->number] = true;
+	mutex_unlock(&snd_ctl_led_mutex);
+	/* the register callback is already called with held card->controls_rwsem */
+	list_for_each_entry(kctl, &card->controls, list)
+		for (ioff = 0; ioff < kctl->count; ioff++)
+			snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
+	snd_ctl_led_refresh();
+	snd_ctl_led_sysfs_add(card);
+}
+
+static void snd_ctl_led_disconnect(struct snd_card *card)
+{
+	snd_ctl_led_sysfs_remove(card);
+	mutex_lock(&snd_ctl_led_mutex);
+	snd_ctl_led_card_valid[card->number] = false;
+	snd_ctl_led_clean(card);
+	mutex_unlock(&snd_ctl_led_mutex);
+	snd_ctl_led_refresh();
+}
+
+static void snd_ctl_led_card_release(struct device *dev)
+{
+	struct snd_ctl_led_card *led_card = to_led_card_dev(dev);
+
+	kfree(led_card);
+}
+
+static void snd_ctl_led_release(struct device *dev)
+{
+}
+
+static void snd_ctl_led_dev_release(struct device *dev)
+{
+}
+
+/*
+ * sysfs
+ */
+
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+	const char *str = NULL;
+
+	switch (led->mode) {
+	case MODE_FOLLOW_MUTE:	str = "follow-mute"; break;
+	case MODE_FOLLOW_ROUTE:	str = "follow-route"; break;
+	case MODE_ON:		str = "on"; break;
+	case MODE_OFF:		str = "off"; break;
+	}
+	return sysfs_emit(buf, "%s\n", str);
+}
+
+static ssize_t mode_store(struct device *dev,
+			  struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+	char _buf[16];
+	size_t l = min(count, sizeof(_buf) - 1);
+	enum snd_ctl_led_mode mode;
+
+	memcpy(_buf, buf, l);
+	_buf[l] = '\0';
+	if (strstr(_buf, "mute"))
+		mode = MODE_FOLLOW_MUTE;
+	else if (strstr(_buf, "route"))
+		mode = MODE_FOLLOW_ROUTE;
+	else if (strncmp(_buf, "off", 3) == 0 || strncmp(_buf, "0", 1) == 0)
+		mode = MODE_OFF;
+	else if (strncmp(_buf, "on", 2) == 0 || strncmp(_buf, "1", 1) == 0)
+		mode = MODE_ON;
+	else
+		return count;
+
+	mutex_lock(&snd_ctl_led_mutex);
+	led->mode = mode;
+	mutex_unlock(&snd_ctl_led_mutex);
+
+	snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
+	return count;
+}
+
+static ssize_t brightness_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+
+	return sysfs_emit(buf, "%u\n", ledtrig_audio_get(led->trigger_type));
+}
+
+static DEVICE_ATTR_RW(mode);
+static DEVICE_ATTR_RO(brightness);
+
+static struct attribute *snd_ctl_led_dev_attrs[] = {
+	&dev_attr_mode.attr,
+	&dev_attr_brightness.attr,
+	NULL,
+};
+
+static const struct attribute_group snd_ctl_led_dev_attr_group = {
+	.attrs = snd_ctl_led_dev_attrs,
+};
+
+static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = {
+	&snd_ctl_led_dev_attr_group,
+	NULL,
+};
+
+static char *find_eos(char *s)
+{
+	while (*s && *s != ',')
+		s++;
+	if (*s)
+		s++;
+	return s;
+}
+
+static char *parse_uint(char *s, unsigned int *val)
+{
+	unsigned long long res;
+	if (kstrtoull(s, 10, &res))
+		res = 0;
+	*val = res;
+	return find_eos(s);
+}
+
+static char *parse_string(char *s, char *val, size_t val_size)
+{
+	if (*s == '"' || *s == '\'') {
+		char c = *s;
+		s++;
+		while (*s && *s != c) {
+			if (val_size > 1) {
+				*val++ = *s;
+				val_size--;
+			}
+			s++;
+		}
+	} else {
+		while (*s && *s != ',') {
+			if (val_size > 1) {
+				*val++ = *s;
+				val_size--;
+			}
+			s++;
+		}
+	}
+	*val = '\0';
+	if (*s)
+		s++;
+	return s;
+}
+
+static char *parse_iface(char *s, snd_ctl_elem_iface_t *val)
+{
+	if (!strncasecmp(s, "card", 4))
+		*val = SNDRV_CTL_ELEM_IFACE_CARD;
+	else if (!strncasecmp(s, "mixer", 5))
+		*val = SNDRV_CTL_ELEM_IFACE_MIXER;
+	return find_eos(s);
+}
+
+/*
+ * These types of input strings are accepted:
+ *
+ *   unsigned integer - numid (equivaled to numid=UINT)
+ *   string - basic mixer name (equivalent to iface=MIXER,name=STR)
+ *   numid=UINT
+ *   [iface=MIXER,][device=UINT,][subdevice=UINT,]name=STR[,index=UINT]
+ */
+static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, size_t count,
+			  bool attach)
+{
+	char buf2[256], *s, *os;
+	struct snd_ctl_elem_id id;
+	int err;
+
+	if (strscpy(buf2, buf, sizeof(buf2)) < 0)
+		return -E2BIG;
+	memset(&id, 0, sizeof(id));
+	id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+	s = buf2;
+	while (*s) {
+		os = s;
+		if (!strncasecmp(s, "numid=", 6)) {
+			s = parse_uint(s + 6, &id.numid);
+		} else if (!strncasecmp(s, "iface=", 6)) {
+			s = parse_iface(s + 6, &id.iface);
+		} else if (!strncasecmp(s, "device=", 7)) {
+			s = parse_uint(s + 7, &id.device);
+		} else if (!strncasecmp(s, "subdevice=", 10)) {
+			s = parse_uint(s + 10, &id.subdevice);
+		} else if (!strncasecmp(s, "name=", 5)) {
+			s = parse_string(s + 5, id.name, sizeof(id.name));
+		} else if (!strncasecmp(s, "index=", 6)) {
+			s = parse_uint(s + 6, &id.index);
+		} else if (s == buf2) {
+			while (*s) {
+				if (*s < '0' || *s > '9')
+					break;
+				s++;
+			}
+			if (*s == '\0')
+				parse_uint(buf2, &id.numid);
+			else {
+				for (; *s >= ' '; s++);
+				*s = '\0';
+				strscpy(id.name, buf2, sizeof(id.name));
+			}
+			break;
+		}
+		if (*s == ',')
+			s++;
+		if (s == os)
+			break;
+	}
+
+	err = snd_ctl_led_set_id(led_card->number, &id, led_card->led->group, attach);
+	if (err < 0)
+		return err;
+
+	return count;
+}
+
+static ssize_t attach_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
+	return set_led_id(led_card, buf, count, true);
+}
+
+static ssize_t detach_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
+	return set_led_id(led_card, buf, count, false);
+}
+
+static ssize_t reset_store(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
+	int err;
+
+	if (count > 0 && buf[0] == '1') {
+		err = snd_ctl_led_reset(led_card->number, led_card->led->group);
+		if (err < 0)
+			return err;
+	}
+	return count;
+}
+
+static ssize_t list_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
+	struct snd_card *card;
+	struct snd_ctl_led_ctl *lctl;
+	size_t l = 0;
+
+	card = snd_card_ref(led_card->number);
+	if (!card)
+		return -ENXIO;
+	down_read(&card->controls_rwsem);
+	mutex_lock(&snd_ctl_led_mutex);
+	if (snd_ctl_led_card_valid[led_card->number]) {
+		list_for_each_entry(lctl, &led_card->led->controls, list) {
+			if (lctl->card != card)
+				continue;
+			if (l)
+				l += sysfs_emit_at(buf, l, " ");
+			l += sysfs_emit_at(buf, l, "%u",
+					   lctl->kctl->id.numid + lctl->index_offset);
+		}
+	}
+	mutex_unlock(&snd_ctl_led_mutex);
+	up_read(&card->controls_rwsem);
+	snd_card_unref(card);
+	return l;
+}
+
+static DEVICE_ATTR_WO(attach);
+static DEVICE_ATTR_WO(detach);
+static DEVICE_ATTR_WO(reset);
+static DEVICE_ATTR_RO(list);
+
+static struct attribute *snd_ctl_led_card_attrs[] = {
+	&dev_attr_attach.attr,
+	&dev_attr_detach.attr,
+	&dev_attr_reset.attr,
+	&dev_attr_list.attr,
+	NULL,
+};
+
+static const struct attribute_group snd_ctl_led_card_attr_group = {
+	.attrs = snd_ctl_led_card_attrs,
+};
+
+static const struct attribute_group *snd_ctl_led_card_attr_groups[] = {
+	&snd_ctl_led_card_attr_group,
+	NULL,
+};
+
+static struct device snd_ctl_led_dev;
+
+static void snd_ctl_led_sysfs_add(struct snd_card *card)
+{
+	unsigned int group;
+	struct snd_ctl_led_card *led_card;
+	struct snd_ctl_led *led;
+	char link_name[32];
+
+	for (group = 0; group < MAX_LED; group++) {
+		led = &snd_ctl_leds[group];
+		led_card = kzalloc(sizeof(*led_card), GFP_KERNEL);
+		if (!led_card)
+			goto cerr2;
+		led_card->number = card->number;
+		led_card->led = led;
+		device_initialize(&led_card->dev);
+		led_card->dev.release = snd_ctl_led_card_release;
+		if (dev_set_name(&led_card->dev, "card%d", card->number) < 0)
+			goto cerr;
+		led_card->dev.parent = &led->dev;
+		led_card->dev.groups = snd_ctl_led_card_attr_groups;
+		if (device_add(&led_card->dev))
+			goto cerr;
+		led->cards[card->number] = led_card;
+		snprintf(link_name, sizeof(link_name), "led-%s", led->name);
+		WARN(sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj, link_name),
+			"can't create symlink to controlC%i device\n", card->number);
+		WARN(sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj, "card"),
+			"can't create symlink to card%i\n", card->number);
+
+		continue;
+cerr:
+		put_device(&led_card->dev);
+cerr2:
+		printk(KERN_ERR "snd_ctl_led: unable to add card%d", card->number);
+	}
+}
+
+static void snd_ctl_led_sysfs_remove(struct snd_card *card)
+{
+	unsigned int group;
+	struct snd_ctl_led_card *led_card;
+	struct snd_ctl_led *led;
+	char link_name[32];
+
+	for (group = 0; group < MAX_LED; group++) {
+		led = &snd_ctl_leds[group];
+		led_card = led->cards[card->number];
+		if (!led_card)
+			continue;
+		snprintf(link_name, sizeof(link_name), "led-%s", led->name);
+		sysfs_remove_link(&card->ctl_dev->kobj, link_name);
+		sysfs_remove_link(&led_card->dev.kobj, "card");
+		device_unregister(&led_card->dev);
+		led->cards[card->number] = NULL;
+	}
+}
+
+/*
+ * Control layer registration
+ */
+static struct snd_ctl_layer_ops snd_ctl_led_lops = {
+	.module_name = SND_CTL_LAYER_MODULE_LED,
+	.lregister = snd_ctl_led_register,
+	.ldisconnect = snd_ctl_led_disconnect,
+	.lnotify = snd_ctl_led_notify,
+};
+
+static int __init snd_ctl_led_init(void)
+{
+	struct snd_ctl_led *led;
+	unsigned int group;
+
+	device_initialize(&snd_ctl_led_dev);
+	snd_ctl_led_dev.class = &sound_class;
+	snd_ctl_led_dev.release = snd_ctl_led_dev_release;
+	dev_set_name(&snd_ctl_led_dev, "ctl-led");
+	if (device_add(&snd_ctl_led_dev)) {
+		put_device(&snd_ctl_led_dev);
+		return -ENOMEM;
+	}
+	for (group = 0; group < MAX_LED; group++) {
+		led = &snd_ctl_leds[group];
+		INIT_LIST_HEAD(&led->controls);
+		device_initialize(&led->dev);
+		led->dev.parent = &snd_ctl_led_dev;
+		led->dev.release = snd_ctl_led_release;
+		led->dev.groups = snd_ctl_led_dev_attr_groups;
+		dev_set_name(&led->dev, led->name);
+		if (device_add(&led->dev)) {
+			put_device(&led->dev);
+			for (; group > 0; group--) {
+				led = &snd_ctl_leds[group - 1];
+				device_unregister(&led->dev);
+			}
+			device_unregister(&snd_ctl_led_dev);
+			return -ENOMEM;
+		}
+	}
+	snd_ctl_register_layer(&snd_ctl_led_lops);
+	return 0;
+}
+
+static void __exit snd_ctl_led_exit(void)
+{
+	struct snd_ctl_led *led;
+	struct snd_card *card;
+	unsigned int group, card_number;
+
+	snd_ctl_disconnect_layer(&snd_ctl_led_lops);
+	for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
+		if (!snd_ctl_led_card_valid[card_number])
+			continue;
+		card = snd_card_ref(card_number);
+		if (card) {
+			snd_ctl_led_sysfs_remove(card);
+			snd_card_unref(card);
+		}
+	}
+	for (group = 0; group < MAX_LED; group++) {
+		led = &snd_ctl_leds[group];
+		device_unregister(&led->dev);
+	}
+	device_unregister(&snd_ctl_led_dev);
+	snd_ctl_led_clean(NULL);
+}
+
+module_init(snd_ctl_led_init)
+module_exit(snd_ctl_led_exit)
diff --git a/sound/core/ctljack.c b/sound/core/ctljack.c
new file mode 100644
index 0000000000..709b1a9c2c
--- /dev/null
+++ b/sound/core/ctljack.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Helper functions for jack-detection kcontrols
+ *
+ * Copyright (c) 2011 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/control.h>
+
+#define jack_detect_kctl_info	snd_ctl_boolean_mono_info
+
+static int jack_detect_kctl_get(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.integer.value[0] = kcontrol->private_value;
+	return 0;
+}
+
+static const struct snd_kcontrol_new jack_detect_kctl = {
+	/* name is filled later */
+	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ,
+	.info = jack_detect_kctl_info,
+	.get = jack_detect_kctl_get,
+};
+
+static int get_available_index(struct snd_card *card, const char *name)
+{
+	struct snd_ctl_elem_id sid;
+
+	memset(&sid, 0, sizeof(sid));
+
+	sid.index = 0;
+	sid.iface = SNDRV_CTL_ELEM_IFACE_CARD;
+	strscpy(sid.name, name, sizeof(sid.name));
+
+	while (snd_ctl_find_id(card, &sid)) {
+		sid.index++;
+		/* reset numid; otherwise snd_ctl_find_id() hits this again */
+		sid.numid = 0;
+	}
+
+	return sid.index;
+}
+
+static void jack_kctl_name_gen(char *name, const char *src_name, int size)
+{
+	size_t count = strlen(src_name);
+	bool need_cat = true;
+
+	/* remove redundant " Jack" from src_name */
+	if (count >= 5)
+		need_cat = strncmp(&src_name[count - 5], " Jack", 5) ? true : false;
+
+	snprintf(name, size, need_cat ? "%s Jack" : "%s", src_name);
+
+}
+
+struct snd_kcontrol *
+snd_kctl_jack_new(const char *name, struct snd_card *card)
+{
+	struct snd_kcontrol *kctl;
+
+	kctl = snd_ctl_new1(&jack_detect_kctl, NULL);
+	if (!kctl)
+		return NULL;
+
+	jack_kctl_name_gen(kctl->id.name, name, sizeof(kctl->id.name));
+	kctl->id.index = get_available_index(card, kctl->id.name);
+	kctl->private_value = 0;
+	return kctl;
+}
+
+void snd_kctl_jack_report(struct snd_card *card,
+			  struct snd_kcontrol *kctl, bool status)
+{
+	if (kctl->private_value == status)
+		return;
+	kctl->private_value = status;
+	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
+}
diff --git a/sound/core/device.c b/sound/core/device.c
new file mode 100644
index 0000000000..b57d80a170
--- /dev/null
+++ b/sound/core/device.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Device management routines
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <sound/core.h>
+
+/**
+ * snd_device_new - create an ALSA device component
+ * @card: the card instance
+ * @type: the device type, SNDRV_DEV_XXX
+ * @device_data: the data pointer of this device
+ * @ops: the operator table
+ *
+ * Creates a new device component for the given data pointer.
+ * The device will be assigned to the card and managed together
+ * by the card.
+ *
+ * The data pointer plays a role as the identifier, too, so the
+ * pointer address must be unique and unchanged.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_device_new(struct snd_card *card, enum snd_device_type type,
+		   void *device_data, const struct snd_device_ops *ops)
+{
+	struct snd_device *dev;
+	struct list_head *p;
+
+	if (snd_BUG_ON(!card || !device_data || !ops))
+		return -ENXIO;
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&dev->list);
+	dev->card = card;
+	dev->type = type;
+	dev->state = SNDRV_DEV_BUILD;
+	dev->device_data = device_data;
+	dev->ops = ops;
+
+	/* insert the entry in an incrementally sorted list */
+	list_for_each_prev(p, &card->devices) {
+		struct snd_device *pdev = list_entry(p, struct snd_device, list);
+		if ((unsigned int)pdev->type <= (unsigned int)type)
+			break;
+	}
+
+	list_add(&dev->list, p);
+	return 0;
+}
+EXPORT_SYMBOL(snd_device_new);
+
+static void __snd_device_disconnect(struct snd_device *dev)
+{
+	if (dev->state == SNDRV_DEV_REGISTERED) {
+		if (dev->ops->dev_disconnect &&
+		    dev->ops->dev_disconnect(dev))
+			dev_err(dev->card->dev, "device disconnect failure\n");
+		dev->state = SNDRV_DEV_DISCONNECTED;
+	}
+}
+
+static void __snd_device_free(struct snd_device *dev)
+{
+	/* unlink */
+	list_del(&dev->list);
+
+	__snd_device_disconnect(dev);
+	if (dev->ops->dev_free) {
+		if (dev->ops->dev_free(dev))
+			dev_err(dev->card->dev, "device free failure\n");
+	}
+	kfree(dev);
+}
+
+static struct snd_device *look_for_dev(struct snd_card *card, void *device_data)
+{
+	struct snd_device *dev;
+
+	list_for_each_entry(dev, &card->devices, list)
+		if (dev->device_data == device_data)
+			return dev;
+
+	return NULL;
+}
+
+/**
+ * snd_device_disconnect - disconnect the device
+ * @card: the card instance
+ * @device_data: the data pointer to disconnect
+ *
+ * Turns the device into the disconnection state, invoking
+ * dev_disconnect callback, if the device was already registered.
+ *
+ * Usually called from snd_card_disconnect().
+ *
+ * Return: Zero if successful, or a negative error code on failure or if the
+ * device not found.
+ */
+void snd_device_disconnect(struct snd_card *card, void *device_data)
+{
+	struct snd_device *dev;
+
+	if (snd_BUG_ON(!card || !device_data))
+		return;
+	dev = look_for_dev(card, device_data);
+	if (dev)
+		__snd_device_disconnect(dev);
+	else
+		dev_dbg(card->dev, "device disconnect %p (from %pS), not found\n",
+			device_data, __builtin_return_address(0));
+}
+EXPORT_SYMBOL_GPL(snd_device_disconnect);
+
+/**
+ * snd_device_free - release the device from the card
+ * @card: the card instance
+ * @device_data: the data pointer to release
+ *
+ * Removes the device from the list on the card and invokes the
+ * callbacks, dev_disconnect and dev_free, corresponding to the state.
+ * Then release the device.
+ */
+void snd_device_free(struct snd_card *card, void *device_data)
+{
+	struct snd_device *dev;
+	
+	if (snd_BUG_ON(!card || !device_data))
+		return;
+	dev = look_for_dev(card, device_data);
+	if (dev)
+		__snd_device_free(dev);
+	else
+		dev_dbg(card->dev, "device free %p (from %pS), not found\n",
+			device_data, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(snd_device_free);
+
+static int __snd_device_register(struct snd_device *dev)
+{
+	if (dev->state == SNDRV_DEV_BUILD) {
+		if (dev->ops->dev_register) {
+			int err = dev->ops->dev_register(dev);
+			if (err < 0)
+				return err;
+		}
+		dev->state = SNDRV_DEV_REGISTERED;
+	}
+	return 0;
+}
+
+/**
+ * snd_device_register - register the device
+ * @card: the card instance
+ * @device_data: the data pointer to register
+ *
+ * Registers the device which was already created via
+ * snd_device_new().  Usually this is called from snd_card_register(),
+ * but it can be called later if any new devices are created after
+ * invocation of snd_card_register().
+ *
+ * Return: Zero if successful, or a negative error code on failure or if the
+ * device not found.
+ */
+int snd_device_register(struct snd_card *card, void *device_data)
+{
+	struct snd_device *dev;
+
+	if (snd_BUG_ON(!card || !device_data))
+		return -ENXIO;
+	dev = look_for_dev(card, device_data);
+	if (dev)
+		return __snd_device_register(dev);
+	snd_BUG();
+	return -ENXIO;
+}
+EXPORT_SYMBOL(snd_device_register);
+
+/*
+ * register all the devices on the card.
+ * called from init.c
+ */
+int snd_device_register_all(struct snd_card *card)
+{
+	struct snd_device *dev;
+	int err;
+	
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+	list_for_each_entry(dev, &card->devices, list) {
+		err = __snd_device_register(dev);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/*
+ * disconnect all the devices on the card.
+ * called from init.c
+ */
+void snd_device_disconnect_all(struct snd_card *card)
+{
+	struct snd_device *dev;
+
+	if (snd_BUG_ON(!card))
+		return;
+	list_for_each_entry_reverse(dev, &card->devices, list)
+		__snd_device_disconnect(dev);
+}
+
+/*
+ * release all the devices on the card.
+ * called from init.c
+ */
+void snd_device_free_all(struct snd_card *card)
+{
+	struct snd_device *dev, *next;
+
+	if (snd_BUG_ON(!card))
+		return;
+	list_for_each_entry_safe_reverse(dev, next, &card->devices, list) {
+		/* exception: free ctl and lowlevel stuff later */
+		if (dev->type == SNDRV_DEV_CONTROL ||
+		    dev->type == SNDRV_DEV_LOWLEVEL)
+			continue;
+		__snd_device_free(dev);
+	}
+
+	/* free all */
+	list_for_each_entry_safe_reverse(dev, next, &card->devices, list)
+		__snd_device_free(dev);
+}
+
+/**
+ * snd_device_get_state - Get the current state of the given device
+ * @card: the card instance
+ * @device_data: the data pointer to release
+ *
+ * Returns the current state of the given device object.  For the valid
+ * device, either @SNDRV_DEV_BUILD, @SNDRV_DEV_REGISTERED or
+ * @SNDRV_DEV_DISCONNECTED is returned.
+ * Or for a non-existing device, -1 is returned as an error.
+ *
+ * Return: the current state, or -1 if not found
+ */
+int snd_device_get_state(struct snd_card *card, void *device_data)
+{
+	struct snd_device *dev;
+
+	dev = look_for_dev(card, device_data);
+	if (dev)
+		return dev->state;
+	return -1;
+}
+EXPORT_SYMBOL_GPL(snd_device_get_state);
diff --git a/sound/core/hrtimer.c b/sound/core/hrtimer.c
new file mode 100644
index 0000000000..e97ff8cccb
--- /dev/null
+++ b/sound/core/hrtimer.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ALSA timer back-end using hrtimer
+ * Copyright (C) 2008 Takashi Iwai
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/hrtimer.h>
+#include <sound/core.h>
+#include <sound/timer.h>
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA hrtimer backend");
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_HRTIMER));
+
+#define NANO_SEC	1000000000UL	/* 10^9 in sec */
+static unsigned int resolution;
+
+struct snd_hrtimer {
+	struct snd_timer *timer;
+	struct hrtimer hrt;
+	bool in_callback;
+};
+
+static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
+{
+	struct snd_hrtimer *stime = container_of(hrt, struct snd_hrtimer, hrt);
+	struct snd_timer *t = stime->timer;
+	ktime_t delta;
+	unsigned long ticks;
+	enum hrtimer_restart ret = HRTIMER_NORESTART;
+
+	spin_lock(&t->lock);
+	if (!t->running)
+		goto out; /* fast path */
+	stime->in_callback = true;
+	ticks = t->sticks;
+	spin_unlock(&t->lock);
+
+	/* calculate the drift */
+	delta = ktime_sub(hrt->base->get_time(), hrtimer_get_expires(hrt));
+	if (delta > 0)
+		ticks += ktime_divns(delta, ticks * resolution);
+
+	snd_timer_interrupt(stime->timer, ticks);
+
+	spin_lock(&t->lock);
+	if (t->running) {
+		hrtimer_add_expires_ns(hrt, t->sticks * resolution);
+		ret = HRTIMER_RESTART;
+	}
+
+	stime->in_callback = false;
+ out:
+	spin_unlock(&t->lock);
+	return ret;
+}
+
+static int snd_hrtimer_open(struct snd_timer *t)
+{
+	struct snd_hrtimer *stime;
+
+	stime = kzalloc(sizeof(*stime), GFP_KERNEL);
+	if (!stime)
+		return -ENOMEM;
+	hrtimer_init(&stime->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	stime->timer = t;
+	stime->hrt.function = snd_hrtimer_callback;
+	t->private_data = stime;
+	return 0;
+}
+
+static int snd_hrtimer_close(struct snd_timer *t)
+{
+	struct snd_hrtimer *stime = t->private_data;
+
+	if (stime) {
+		spin_lock_irq(&t->lock);
+		t->running = 0; /* just to be sure */
+		stime->in_callback = 1; /* skip start/stop */
+		spin_unlock_irq(&t->lock);
+
+		hrtimer_cancel(&stime->hrt);
+		kfree(stime);
+		t->private_data = NULL;
+	}
+	return 0;
+}
+
+static int snd_hrtimer_start(struct snd_timer *t)
+{
+	struct snd_hrtimer *stime = t->private_data;
+
+	if (stime->in_callback)
+		return 0;
+	hrtimer_start(&stime->hrt, ns_to_ktime(t->sticks * resolution),
+		      HRTIMER_MODE_REL);
+	return 0;
+}
+
+static int snd_hrtimer_stop(struct snd_timer *t)
+{
+	struct snd_hrtimer *stime = t->private_data;
+
+	if (stime->in_callback)
+		return 0;
+	hrtimer_try_to_cancel(&stime->hrt);
+	return 0;
+}
+
+static const struct snd_timer_hardware hrtimer_hw __initconst = {
+	.flags =	SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_WORK,
+	.open =		snd_hrtimer_open,
+	.close =	snd_hrtimer_close,
+	.start =	snd_hrtimer_start,
+	.stop =		snd_hrtimer_stop,
+};
+
+/*
+ * entry functions
+ */
+
+static struct snd_timer *mytimer;
+
+static int __init snd_hrtimer_init(void)
+{
+	struct snd_timer *timer;
+	int err;
+
+	resolution = hrtimer_resolution;
+
+	/* Create a new timer and set up the fields */
+	err = snd_timer_global_new("hrtimer", SNDRV_TIMER_GLOBAL_HRTIMER,
+				   &timer);
+	if (err < 0)
+		return err;
+
+	timer->module = THIS_MODULE;
+	strcpy(timer->name, "HR timer");
+	timer->hw = hrtimer_hw;
+	timer->hw.resolution = resolution;
+	timer->hw.ticks = NANO_SEC / resolution;
+	timer->max_instances = 100; /* lower the limit */
+
+	err = snd_timer_global_register(timer);
+	if (err < 0) {
+		snd_timer_global_free(timer);
+		return err;
+	}
+	mytimer = timer; /* remember this */
+
+	return 0;
+}
+
+static void __exit snd_hrtimer_exit(void)
+{
+	if (mytimer) {
+		snd_timer_global_free(mytimer);
+		mytimer = NULL;
+	}
+}
+
+module_init(snd_hrtimer_init);
+module_exit(snd_hrtimer_exit);
diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
new file mode 100644
index 0000000000..de7476034f
--- /dev/null
+++ b/sound/core/hwdep.c
@@ -0,0 +1,549 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Hardware dependent layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/major.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/minors.h>
+#include <sound/hwdep.h>
+#include <sound/info.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Hardware dependent layer");
+MODULE_LICENSE("GPL");
+
+static LIST_HEAD(snd_hwdep_devices);
+static DEFINE_MUTEX(register_mutex);
+
+static int snd_hwdep_dev_free(struct snd_device *device);
+static int snd_hwdep_dev_register(struct snd_device *device);
+static int snd_hwdep_dev_disconnect(struct snd_device *device);
+
+
+static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
+{
+	struct snd_hwdep *hwdep;
+
+	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
+		if (hwdep->card == card && hwdep->device == device)
+			return hwdep;
+	return NULL;
+}
+
+static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
+{
+	struct snd_hwdep *hw = file->private_data;
+	if (hw->ops.llseek)
+		return hw->ops.llseek(hw, file, offset, orig);
+	return -ENXIO;
+}
+
+static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
+			      size_t count, loff_t *offset)
+{
+	struct snd_hwdep *hw = file->private_data;
+	if (hw->ops.read)
+		return hw->ops.read(hw, buf, count, offset);
+	return -ENXIO;	
+}
+
+static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
+			       size_t count, loff_t *offset)
+{
+	struct snd_hwdep *hw = file->private_data;
+	if (hw->ops.write)
+		return hw->ops.write(hw, buf, count, offset);
+	return -ENXIO;	
+}
+
+static int snd_hwdep_open(struct inode *inode, struct file * file)
+{
+	int major = imajor(inode);
+	struct snd_hwdep *hw;
+	int err;
+	wait_queue_entry_t wait;
+
+	if (major == snd_major) {
+		hw = snd_lookup_minor_data(iminor(inode),
+					   SNDRV_DEVICE_TYPE_HWDEP);
+#ifdef CONFIG_SND_OSSEMUL
+	} else if (major == SOUND_MAJOR) {
+		hw = snd_lookup_oss_minor_data(iminor(inode),
+					       SNDRV_OSS_DEVICE_TYPE_DMFM);
+#endif
+	} else
+		return -ENXIO;
+	if (hw == NULL)
+		return -ENODEV;
+
+	if (!try_module_get(hw->card->module)) {
+		snd_card_unref(hw->card);
+		return -EFAULT;
+	}
+
+	init_waitqueue_entry(&wait, current);
+	add_wait_queue(&hw->open_wait, &wait);
+	mutex_lock(&hw->open_mutex);
+	while (1) {
+		if (hw->exclusive && hw->used > 0) {
+			err = -EBUSY;
+			break;
+		}
+		if (!hw->ops.open) {
+			err = 0;
+			break;
+		}
+		err = hw->ops.open(hw, file);
+		if (err >= 0)
+			break;
+		if (err == -EAGAIN) {
+			if (file->f_flags & O_NONBLOCK) {
+				err = -EBUSY;
+				break;
+			}
+		} else
+			break;
+		set_current_state(TASK_INTERRUPTIBLE);
+		mutex_unlock(&hw->open_mutex);
+		schedule();
+		mutex_lock(&hw->open_mutex);
+		if (hw->card->shutdown) {
+			err = -ENODEV;
+			break;
+		}
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+	}
+	remove_wait_queue(&hw->open_wait, &wait);
+	if (err >= 0) {
+		err = snd_card_file_add(hw->card, file);
+		if (err >= 0) {
+			file->private_data = hw;
+			hw->used++;
+		} else {
+			if (hw->ops.release)
+				hw->ops.release(hw, file);
+		}
+	}
+	mutex_unlock(&hw->open_mutex);
+	if (err < 0)
+		module_put(hw->card->module);
+	snd_card_unref(hw->card);
+	return err;
+}
+
+static int snd_hwdep_release(struct inode *inode, struct file * file)
+{
+	int err = 0;
+	struct snd_hwdep *hw = file->private_data;
+	struct module *mod = hw->card->module;
+
+	mutex_lock(&hw->open_mutex);
+	if (hw->ops.release)
+		err = hw->ops.release(hw, file);
+	if (hw->used > 0)
+		hw->used--;
+	mutex_unlock(&hw->open_mutex);
+	wake_up(&hw->open_wait);
+
+	snd_card_file_remove(hw->card, file);
+	module_put(mod);
+	return err;
+}
+
+static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
+{
+	struct snd_hwdep *hw = file->private_data;
+	if (hw->ops.poll)
+		return hw->ops.poll(hw, file, wait);
+	return 0;
+}
+
+static int snd_hwdep_info(struct snd_hwdep *hw,
+			  struct snd_hwdep_info __user *_info)
+{
+	struct snd_hwdep_info info;
+	
+	memset(&info, 0, sizeof(info));
+	info.card = hw->card->number;
+	strscpy(info.id, hw->id, sizeof(info.id));
+	strscpy(info.name, hw->name, sizeof(info.name));
+	info.iface = hw->iface;
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
+				struct snd_hwdep_dsp_status __user *_info)
+{
+	struct snd_hwdep_dsp_status info;
+	int err;
+	
+	if (! hw->ops.dsp_status)
+		return -ENXIO;
+	memset(&info, 0, sizeof(info));
+	info.dsp_loaded = hw->dsp_loaded;
+	err = hw->ops.dsp_status(hw, &info);
+	if (err < 0)
+		return err;
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
+			      struct snd_hwdep_dsp_image *info)
+{
+	int err;
+	
+	if (! hw->ops.dsp_load)
+		return -ENXIO;
+	if (info->index >= 32)
+		return -EINVAL;
+	/* check whether the dsp was already loaded */
+	if (hw->dsp_loaded & (1u << info->index))
+		return -EBUSY;
+	err = hw->ops.dsp_load(hw, info);
+	if (err < 0)
+		return err;
+	hw->dsp_loaded |= (1u << info->index);
+	return 0;
+}
+
+static int snd_hwdep_dsp_load_user(struct snd_hwdep *hw,
+				   struct snd_hwdep_dsp_image __user *_info)
+{
+	struct snd_hwdep_dsp_image info = {};
+
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	return snd_hwdep_dsp_load(hw, &info);
+}
+
+
+static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
+			    unsigned long arg)
+{
+	struct snd_hwdep *hw = file->private_data;
+	void __user *argp = (void __user *)arg;
+	switch (cmd) {
+	case SNDRV_HWDEP_IOCTL_PVERSION:
+		return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
+	case SNDRV_HWDEP_IOCTL_INFO:
+		return snd_hwdep_info(hw, argp);
+	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
+		return snd_hwdep_dsp_status(hw, argp);
+	case SNDRV_HWDEP_IOCTL_DSP_LOAD:
+		return snd_hwdep_dsp_load_user(hw, argp);
+	}
+	if (hw->ops.ioctl)
+		return hw->ops.ioctl(hw, file, cmd, arg);
+	return -ENOTTY;
+}
+
+static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	struct snd_hwdep *hw = file->private_data;
+	if (hw->ops.mmap)
+		return hw->ops.mmap(hw, file, vma);
+	return -ENXIO;
+}
+
+static int snd_hwdep_control_ioctl(struct snd_card *card,
+				   struct snd_ctl_file * control,
+				   unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
+		{
+			int device;
+
+			if (get_user(device, (int __user *)arg))
+				return -EFAULT;
+			mutex_lock(&register_mutex);
+
+			if (device < 0)
+				device = 0;
+			else if (device < SNDRV_MINOR_HWDEPS)
+				device++;
+			else
+				device = SNDRV_MINOR_HWDEPS;
+
+			while (device < SNDRV_MINOR_HWDEPS) {
+				if (snd_hwdep_search(card, device))
+					break;
+				device++;
+			}
+			if (device >= SNDRV_MINOR_HWDEPS)
+				device = -1;
+			mutex_unlock(&register_mutex);
+			if (put_user(device, (int __user *)arg))
+				return -EFAULT;
+			return 0;
+		}
+	case SNDRV_CTL_IOCTL_HWDEP_INFO:
+		{
+			struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
+			int device, err;
+			struct snd_hwdep *hwdep;
+
+			if (get_user(device, &info->device))
+				return -EFAULT;
+			mutex_lock(&register_mutex);
+			hwdep = snd_hwdep_search(card, device);
+			if (hwdep)
+				err = snd_hwdep_info(hwdep, info);
+			else
+				err = -ENXIO;
+			mutex_unlock(&register_mutex);
+			return err;
+		}
+	}
+	return -ENOIOCTLCMD;
+}
+
+#ifdef CONFIG_COMPAT
+#include "hwdep_compat.c"
+#else
+#define snd_hwdep_ioctl_compat	NULL
+#endif
+
+/*
+
+ */
+
+static const struct file_operations snd_hwdep_f_ops =
+{
+	.owner = 	THIS_MODULE,
+	.llseek =	snd_hwdep_llseek,
+	.read = 	snd_hwdep_read,
+	.write =	snd_hwdep_write,
+	.open =		snd_hwdep_open,
+	.release =	snd_hwdep_release,
+	.poll =		snd_hwdep_poll,
+	.unlocked_ioctl =	snd_hwdep_ioctl,
+	.compat_ioctl =	snd_hwdep_ioctl_compat,
+	.mmap =		snd_hwdep_mmap,
+};
+
+static void snd_hwdep_free(struct snd_hwdep *hwdep)
+{
+	if (!hwdep)
+		return;
+	if (hwdep->private_free)
+		hwdep->private_free(hwdep);
+	put_device(hwdep->dev);
+	kfree(hwdep);
+}
+
+/**
+ * snd_hwdep_new - create a new hwdep instance
+ * @card: the card instance
+ * @id: the id string
+ * @device: the device index (zero-based)
+ * @rhwdep: the pointer to store the new hwdep instance
+ *
+ * Creates a new hwdep instance with the given index on the card.
+ * The callbacks (hwdep->ops) must be set on the returned instance
+ * after this call manually by the caller.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_hwdep_new(struct snd_card *card, char *id, int device,
+		  struct snd_hwdep **rhwdep)
+{
+	struct snd_hwdep *hwdep;
+	int err;
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_hwdep_dev_free,
+		.dev_register = snd_hwdep_dev_register,
+		.dev_disconnect = snd_hwdep_dev_disconnect,
+	};
+
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+	if (rhwdep)
+		*rhwdep = NULL;
+	hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
+	if (!hwdep)
+		return -ENOMEM;
+
+	init_waitqueue_head(&hwdep->open_wait);
+	mutex_init(&hwdep->open_mutex);
+	hwdep->card = card;
+	hwdep->device = device;
+	if (id)
+		strscpy(hwdep->id, id, sizeof(hwdep->id));
+
+	err = snd_device_alloc(&hwdep->dev, card);
+	if (err < 0) {
+		snd_hwdep_free(hwdep);
+		return err;
+	}
+
+	dev_set_name(hwdep->dev, "hwC%iD%i", card->number, device);
+#ifdef CONFIG_SND_OSSEMUL
+	hwdep->oss_type = -1;
+#endif
+
+	err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
+	if (err < 0) {
+		snd_hwdep_free(hwdep);
+		return err;
+	}
+
+	if (rhwdep)
+		*rhwdep = hwdep;
+	return 0;
+}
+EXPORT_SYMBOL(snd_hwdep_new);
+
+static int snd_hwdep_dev_free(struct snd_device *device)
+{
+	snd_hwdep_free(device->device_data);
+	return 0;
+}
+
+static int snd_hwdep_dev_register(struct snd_device *device)
+{
+	struct snd_hwdep *hwdep = device->device_data;
+	struct snd_card *card = hwdep->card;
+	int err;
+
+	mutex_lock(&register_mutex);
+	if (snd_hwdep_search(card, hwdep->device)) {
+		mutex_unlock(&register_mutex);
+		return -EBUSY;
+	}
+	list_add_tail(&hwdep->list, &snd_hwdep_devices);
+	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
+				  hwdep->card, hwdep->device,
+				  &snd_hwdep_f_ops, hwdep, hwdep->dev);
+	if (err < 0) {
+		dev_err(hwdep->dev, "unable to register\n");
+		list_del(&hwdep->list);
+		mutex_unlock(&register_mutex);
+		return err;
+	}
+
+#ifdef CONFIG_SND_OSSEMUL
+	hwdep->ossreg = 0;
+	if (hwdep->oss_type >= 0) {
+		if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
+		    hwdep->device)
+			dev_warn(hwdep->dev,
+				 "only hwdep device 0 can be registered as OSS direct FM device!\n");
+		else if (snd_register_oss_device(hwdep->oss_type,
+						 card, hwdep->device,
+						 &snd_hwdep_f_ops, hwdep) < 0)
+			dev_warn(hwdep->dev,
+				 "unable to register OSS compatibility device\n");
+		else
+			hwdep->ossreg = 1;
+	}
+#endif
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+static int snd_hwdep_dev_disconnect(struct snd_device *device)
+{
+	struct snd_hwdep *hwdep = device->device_data;
+
+	if (snd_BUG_ON(!hwdep))
+		return -ENXIO;
+	mutex_lock(&register_mutex);
+	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
+		mutex_unlock(&register_mutex);
+		return -EINVAL;
+	}
+	mutex_lock(&hwdep->open_mutex);
+	wake_up(&hwdep->open_wait);
+#ifdef CONFIG_SND_OSSEMUL
+	if (hwdep->ossreg)
+		snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
+#endif
+	snd_unregister_device(hwdep->dev);
+	list_del_init(&hwdep->list);
+	mutex_unlock(&hwdep->open_mutex);
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ *  Info interface
+ */
+
+static void snd_hwdep_proc_read(struct snd_info_entry *entry,
+				struct snd_info_buffer *buffer)
+{
+	struct snd_hwdep *hwdep;
+
+	mutex_lock(&register_mutex);
+	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
+		snd_iprintf(buffer, "%02i-%02i: %s\n",
+			    hwdep->card->number, hwdep->device, hwdep->name);
+	mutex_unlock(&register_mutex);
+}
+
+static struct snd_info_entry *snd_hwdep_proc_entry;
+
+static void __init snd_hwdep_proc_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL);
+	if (entry) {
+		entry->c.text.read = snd_hwdep_proc_read;
+		if (snd_info_register(entry) < 0) {
+			snd_info_free_entry(entry);
+			entry = NULL;
+		}
+	}
+	snd_hwdep_proc_entry = entry;
+}
+
+static void __exit snd_hwdep_proc_done(void)
+{
+	snd_info_free_entry(snd_hwdep_proc_entry);
+}
+#else /* !CONFIG_SND_PROC_FS */
+#define snd_hwdep_proc_init()
+#define snd_hwdep_proc_done()
+#endif /* CONFIG_SND_PROC_FS */
+
+
+/*
+ *  ENTRY functions
+ */
+
+static int __init alsa_hwdep_init(void)
+{
+	snd_hwdep_proc_init();
+	snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
+	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
+	return 0;
+}
+
+static void __exit alsa_hwdep_exit(void)
+{
+	snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
+	snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
+	snd_hwdep_proc_done();
+}
+
+module_init(alsa_hwdep_init)
+module_exit(alsa_hwdep_exit)
diff --git a/sound/core/hwdep_compat.c b/sound/core/hwdep_compat.c
new file mode 100644
index 0000000000..a0b76706c0
--- /dev/null
+++ b/sound/core/hwdep_compat.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   32bit -> 64bit ioctl wrapper for hwdep API
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ */
+
+/* This file is included from hwdep.c */
+
+#include <linux/compat.h>
+
+struct snd_hwdep_dsp_image32 {
+	u32 index;
+	unsigned char name[64];
+	u32 image;	/* pointer */
+	u32 length;
+	u32 driver_data;
+} /* don't set packed attribute here */;
+
+static int snd_hwdep_dsp_load_compat(struct snd_hwdep *hw,
+				     struct snd_hwdep_dsp_image32 __user *src)
+{
+	struct snd_hwdep_dsp_image info = {};
+	compat_caddr_t ptr;
+
+	if (copy_from_user(&info, src, 4 + 64) ||
+	    get_user(ptr, &src->image) ||
+	    get_user(info.length, &src->length) ||
+	    get_user(info.driver_data, &src->driver_data))
+		return -EFAULT;
+	info.image = compat_ptr(ptr);
+
+	return snd_hwdep_dsp_load(hw, &info);
+}
+
+enum {
+	SNDRV_HWDEP_IOCTL_DSP_LOAD32   = _IOW('H', 0x03, struct snd_hwdep_dsp_image32)
+};
+
+static long snd_hwdep_ioctl_compat(struct file * file, unsigned int cmd,
+				   unsigned long arg)
+{
+	struct snd_hwdep *hw = file->private_data;
+	void __user *argp = compat_ptr(arg);
+	switch (cmd) {
+	case SNDRV_HWDEP_IOCTL_PVERSION:
+	case SNDRV_HWDEP_IOCTL_INFO:
+	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
+		return snd_hwdep_ioctl(file, cmd, (unsigned long)argp);
+	case SNDRV_HWDEP_IOCTL_DSP_LOAD32:
+		return snd_hwdep_dsp_load_compat(hw, argp);
+	}
+	if (hw->ops.ioctl_compat)
+		return hw->ops.ioctl_compat(hw, file, cmd, arg);
+	return -ENOIOCTLCMD;
+}
diff --git a/sound/core/info.c b/sound/core/info.c
new file mode 100644
index 0000000000..e2f302e55b
--- /dev/null
+++ b/sound/core/info.c
@@ -0,0 +1,920 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Information interface for ALSA driver
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/info.h>
+#include <linux/utsname.h>
+#include <linux/proc_fs.h>
+#include <linux/mutex.h>
+
+int snd_info_check_reserved_words(const char *str)
+{
+	static const char * const reserved[] =
+	{
+		"version",
+		"meminfo",
+		"memdebug",
+		"detect",
+		"devices",
+		"oss",
+		"cards",
+		"timers",
+		"synth",
+		"pcm",
+		"seq",
+		NULL
+	};
+	const char * const *xstr = reserved;
+
+	while (*xstr) {
+		if (!strcmp(*xstr, str))
+			return 0;
+		xstr++;
+	}
+	if (!strncmp(str, "card", 4))
+		return 0;
+	return 1;
+}
+
+static DEFINE_MUTEX(info_mutex);
+
+struct snd_info_private_data {
+	struct snd_info_buffer *rbuffer;
+	struct snd_info_buffer *wbuffer;
+	struct snd_info_entry *entry;
+	void *file_private_data;
+};
+
+static int snd_info_version_init(void);
+static void snd_info_clear_entries(struct snd_info_entry *entry);
+
+/*
+
+ */
+
+static struct snd_info_entry *snd_proc_root;
+struct snd_info_entry *snd_seq_root;
+EXPORT_SYMBOL(snd_seq_root);
+
+#ifdef CONFIG_SND_OSSEMUL
+struct snd_info_entry *snd_oss_root;
+#endif
+
+static int alloc_info_private(struct snd_info_entry *entry,
+			      struct snd_info_private_data **ret)
+{
+	struct snd_info_private_data *data;
+
+	if (!entry || !entry->p)
+		return -ENODEV;
+	if (!try_module_get(entry->module))
+		return -EFAULT;
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		module_put(entry->module);
+		return -ENOMEM;
+	}
+	data->entry = entry;
+	*ret = data;
+	return 0;
+}
+
+static bool valid_pos(loff_t pos, size_t count)
+{
+	if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
+		return false;
+	if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
+		return false;
+	return true;
+}
+
+/*
+ * file ops for binary proc files
+ */
+static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
+{
+	struct snd_info_private_data *data;
+	struct snd_info_entry *entry;
+	loff_t ret = -EINVAL, size;
+
+	data = file->private_data;
+	entry = data->entry;
+	mutex_lock(&entry->access);
+	if (entry->c.ops->llseek) {
+		ret = entry->c.ops->llseek(entry,
+					   data->file_private_data,
+					   file, offset, orig);
+		goto out;
+	}
+
+	size = entry->size;
+	switch (orig) {
+	case SEEK_SET:
+		break;
+	case SEEK_CUR:
+		offset += file->f_pos;
+		break;
+	case SEEK_END:
+		if (!size)
+			goto out;
+		offset += size;
+		break;
+	default:
+		goto out;
+	}
+	if (offset < 0)
+		goto out;
+	if (size && offset > size)
+		offset = size;
+	file->f_pos = offset;
+	ret = offset;
+ out:
+	mutex_unlock(&entry->access);
+	return ret;
+}
+
+static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
+				   size_t count, loff_t * offset)
+{
+	struct snd_info_private_data *data = file->private_data;
+	struct snd_info_entry *entry = data->entry;
+	size_t size;
+	loff_t pos;
+
+	pos = *offset;
+	if (!valid_pos(pos, count))
+		return -EIO;
+	if (pos >= entry->size)
+		return 0;
+	size = entry->size - pos;
+	size = min(count, size);
+	size = entry->c.ops->read(entry, data->file_private_data,
+				  file, buffer, size, pos);
+	if ((ssize_t) size > 0)
+		*offset = pos + size;
+	return size;
+}
+
+static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
+				    size_t count, loff_t * offset)
+{
+	struct snd_info_private_data *data = file->private_data;
+	struct snd_info_entry *entry = data->entry;
+	ssize_t size = 0;
+	loff_t pos;
+
+	pos = *offset;
+	if (!valid_pos(pos, count))
+		return -EIO;
+	if (count > 0) {
+		size_t maxsize = entry->size - pos;
+		count = min(count, maxsize);
+		size = entry->c.ops->write(entry, data->file_private_data,
+					   file, buffer, count, pos);
+	}
+	if (size > 0)
+		*offset = pos + size;
+	return size;
+}
+
+static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
+{
+	struct snd_info_private_data *data = file->private_data;
+	struct snd_info_entry *entry = data->entry;
+	__poll_t mask = 0;
+
+	if (entry->c.ops->poll)
+		return entry->c.ops->poll(entry,
+					  data->file_private_data,
+					  file, wait);
+	if (entry->c.ops->read)
+		mask |= EPOLLIN | EPOLLRDNORM;
+	if (entry->c.ops->write)
+		mask |= EPOLLOUT | EPOLLWRNORM;
+	return mask;
+}
+
+static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	struct snd_info_private_data *data = file->private_data;
+	struct snd_info_entry *entry = data->entry;
+
+	if (!entry->c.ops->ioctl)
+		return -ENOTTY;
+	return entry->c.ops->ioctl(entry, data->file_private_data,
+				   file, cmd, arg);
+}
+
+static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct inode *inode = file_inode(file);
+	struct snd_info_private_data *data;
+	struct snd_info_entry *entry;
+
+	data = file->private_data;
+	if (data == NULL)
+		return 0;
+	entry = data->entry;
+	if (!entry->c.ops->mmap)
+		return -ENXIO;
+	return entry->c.ops->mmap(entry, data->file_private_data,
+				  inode, file, vma);
+}
+
+static int snd_info_entry_open(struct inode *inode, struct file *file)
+{
+	struct snd_info_entry *entry = pde_data(inode);
+	struct snd_info_private_data *data;
+	int mode, err;
+
+	mutex_lock(&info_mutex);
+	err = alloc_info_private(entry, &data);
+	if (err < 0)
+		goto unlock;
+
+	mode = file->f_flags & O_ACCMODE;
+	if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
+	    ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
+		err = -ENODEV;
+		goto error;
+	}
+
+	if (entry->c.ops->open) {
+		err = entry->c.ops->open(entry, mode, &data->file_private_data);
+		if (err < 0)
+			goto error;
+	}
+
+	file->private_data = data;
+	mutex_unlock(&info_mutex);
+	return 0;
+
+ error:
+	kfree(data);
+	module_put(entry->module);
+ unlock:
+	mutex_unlock(&info_mutex);
+	return err;
+}
+
+static int snd_info_entry_release(struct inode *inode, struct file *file)
+{
+	struct snd_info_private_data *data = file->private_data;
+	struct snd_info_entry *entry = data->entry;
+
+	if (entry->c.ops->release)
+		entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
+				      data->file_private_data);
+	module_put(entry->module);
+	kfree(data);
+	return 0;
+}
+
+static const struct proc_ops snd_info_entry_operations =
+{
+	.proc_lseek	= snd_info_entry_llseek,
+	.proc_read	= snd_info_entry_read,
+	.proc_write	= snd_info_entry_write,
+	.proc_poll	= snd_info_entry_poll,
+	.proc_ioctl	= snd_info_entry_ioctl,
+	.proc_mmap	= snd_info_entry_mmap,
+	.proc_open	= snd_info_entry_open,
+	.proc_release	= snd_info_entry_release,
+};
+
+/*
+ * file ops for text proc files
+ */
+static ssize_t snd_info_text_entry_write(struct file *file,
+					 const char __user *buffer,
+					 size_t count, loff_t *offset)
+{
+	struct seq_file *m = file->private_data;
+	struct snd_info_private_data *data = m->private;
+	struct snd_info_entry *entry = data->entry;
+	struct snd_info_buffer *buf;
+	loff_t pos;
+	size_t next;
+	int err = 0;
+
+	if (!entry->c.text.write)
+		return -EIO;
+	pos = *offset;
+	if (!valid_pos(pos, count))
+		return -EIO;
+	next = pos + count;
+	/* don't handle too large text inputs */
+	if (next > 16 * 1024)
+		return -EIO;
+	mutex_lock(&entry->access);
+	buf = data->wbuffer;
+	if (!buf) {
+		data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+		if (!buf) {
+			err = -ENOMEM;
+			goto error;
+		}
+	}
+	if (next > buf->len) {
+		char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
+		if (!nbuf) {
+			err = -ENOMEM;
+			goto error;
+		}
+		kvfree(buf->buffer);
+		buf->buffer = nbuf;
+		buf->len = PAGE_ALIGN(next);
+	}
+	if (copy_from_user(buf->buffer + pos, buffer, count)) {
+		err = -EFAULT;
+		goto error;
+	}
+	buf->size = next;
+ error:
+	mutex_unlock(&entry->access);
+	if (err < 0)
+		return err;
+	*offset = next;
+	return count;
+}
+
+static int snd_info_seq_show(struct seq_file *seq, void *p)
+{
+	struct snd_info_private_data *data = seq->private;
+	struct snd_info_entry *entry = data->entry;
+
+	if (!entry->c.text.read) {
+		return -EIO;
+	} else {
+		data->rbuffer->buffer = (char *)seq; /* XXX hack! */
+		entry->c.text.read(entry, data->rbuffer);
+	}
+	return 0;
+}
+
+static int snd_info_text_entry_open(struct inode *inode, struct file *file)
+{
+	struct snd_info_entry *entry = pde_data(inode);
+	struct snd_info_private_data *data;
+	int err;
+
+	mutex_lock(&info_mutex);
+	err = alloc_info_private(entry, &data);
+	if (err < 0)
+		goto unlock;
+
+	data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
+	if (!data->rbuffer) {
+		err = -ENOMEM;
+		goto error;
+	}
+	if (entry->size)
+		err = single_open_size(file, snd_info_seq_show, data,
+				       entry->size);
+	else
+		err = single_open(file, snd_info_seq_show, data);
+	if (err < 0)
+		goto error;
+	mutex_unlock(&info_mutex);
+	return 0;
+
+ error:
+	kfree(data->rbuffer);
+	kfree(data);
+	module_put(entry->module);
+ unlock:
+	mutex_unlock(&info_mutex);
+	return err;
+}
+
+static int snd_info_text_entry_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *m = file->private_data;
+	struct snd_info_private_data *data = m->private;
+	struct snd_info_entry *entry = data->entry;
+
+	if (data->wbuffer && entry->c.text.write)
+		entry->c.text.write(entry, data->wbuffer);
+
+	single_release(inode, file);
+	kfree(data->rbuffer);
+	if (data->wbuffer) {
+		kvfree(data->wbuffer->buffer);
+		kfree(data->wbuffer);
+	}
+
+	module_put(entry->module);
+	kfree(data);
+	return 0;
+}
+
+static const struct proc_ops snd_info_text_entry_ops =
+{
+	.proc_open	= snd_info_text_entry_open,
+	.proc_release	= snd_info_text_entry_release,
+	.proc_write	= snd_info_text_entry_write,
+	.proc_lseek	= seq_lseek,
+	.proc_read	= seq_read,
+};
+
+static struct snd_info_entry *create_subdir(struct module *mod,
+					    const char *name)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(mod, name, NULL);
+	if (!entry)
+		return NULL;
+	entry->mode = S_IFDIR | 0555;
+	if (snd_info_register(entry) < 0) {
+		snd_info_free_entry(entry);
+		return NULL;
+	}
+	return entry;
+}
+
+static struct snd_info_entry *
+snd_info_create_entry(const char *name, struct snd_info_entry *parent,
+		      struct module *module);
+
+int __init snd_info_init(void)
+{
+	snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
+	if (!snd_proc_root)
+		return -ENOMEM;
+	snd_proc_root->mode = S_IFDIR | 0555;
+	snd_proc_root->p = proc_mkdir("asound", NULL);
+	if (!snd_proc_root->p)
+		goto error;
+#ifdef CONFIG_SND_OSSEMUL
+	snd_oss_root = create_subdir(THIS_MODULE, "oss");
+	if (!snd_oss_root)
+		goto error;
+#endif
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+	snd_seq_root = create_subdir(THIS_MODULE, "seq");
+	if (!snd_seq_root)
+		goto error;
+#endif
+	if (snd_info_version_init() < 0 ||
+	    snd_minor_info_init() < 0 ||
+	    snd_minor_info_oss_init() < 0 ||
+	    snd_card_info_init() < 0 ||
+	    snd_info_minor_register() < 0)
+		goto error;
+	return 0;
+
+ error:
+	snd_info_free_entry(snd_proc_root);
+	return -ENOMEM;
+}
+
+int __exit snd_info_done(void)
+{
+	snd_info_free_entry(snd_proc_root);
+	return 0;
+}
+
+static void snd_card_id_read(struct snd_info_entry *entry,
+			     struct snd_info_buffer *buffer)
+{
+	struct snd_card *card = entry->private_data;
+
+	snd_iprintf(buffer, "%s\n", card->id);
+}
+
+/*
+ * create a card proc file
+ * called from init.c
+ */
+int snd_info_card_create(struct snd_card *card)
+{
+	char str[8];
+	struct snd_info_entry *entry;
+
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+
+	sprintf(str, "card%i", card->number);
+	entry = create_subdir(card->module, str);
+	if (!entry)
+		return -ENOMEM;
+	card->proc_root = entry;
+
+	return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
+}
+
+/*
+ * register the card proc file
+ * called from init.c
+ * can be called multiple times for reinitialization
+ */
+int snd_info_card_register(struct snd_card *card)
+{
+	struct proc_dir_entry *p;
+	int err;
+
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+
+	err = snd_info_register(card->proc_root);
+	if (err < 0)
+		return err;
+
+	if (!strcmp(card->id, card->proc_root->name))
+		return 0;
+
+	if (card->proc_root_link)
+		return 0;
+	p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
+	if (!p)
+		return -ENOMEM;
+	card->proc_root_link = p;
+	return 0;
+}
+
+/*
+ * called on card->id change
+ */
+void snd_info_card_id_change(struct snd_card *card)
+{
+	mutex_lock(&info_mutex);
+	if (card->proc_root_link) {
+		proc_remove(card->proc_root_link);
+		card->proc_root_link = NULL;
+	}
+	if (strcmp(card->id, card->proc_root->name))
+		card->proc_root_link = proc_symlink(card->id,
+						    snd_proc_root->p,
+						    card->proc_root->name);
+	mutex_unlock(&info_mutex);
+}
+
+/*
+ * de-register the card proc file
+ * called from init.c
+ */
+void snd_info_card_disconnect(struct snd_card *card)
+{
+	if (!card)
+		return;
+
+	proc_remove(card->proc_root_link);
+	if (card->proc_root)
+		proc_remove(card->proc_root->p);
+
+	mutex_lock(&info_mutex);
+	if (card->proc_root)
+		snd_info_clear_entries(card->proc_root);
+	card->proc_root_link = NULL;
+	card->proc_root = NULL;
+	mutex_unlock(&info_mutex);
+}
+
+/*
+ * release the card proc file resources
+ * called from init.c
+ */
+int snd_info_card_free(struct snd_card *card)
+{
+	if (!card)
+		return 0;
+	snd_info_free_entry(card->proc_root);
+	card->proc_root = NULL;
+	return 0;
+}
+
+
+/**
+ * snd_info_get_line - read one line from the procfs buffer
+ * @buffer: the procfs buffer
+ * @line: the buffer to store
+ * @len: the max. buffer size
+ *
+ * Reads one line from the buffer and stores the string.
+ *
+ * Return: Zero if successful, or 1 if error or EOF.
+ */
+int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
+{
+	int c;
+
+	if (snd_BUG_ON(!buffer))
+		return 1;
+	if (!buffer->buffer)
+		return 1;
+	if (len <= 0 || buffer->stop || buffer->error)
+		return 1;
+	while (!buffer->stop) {
+		c = buffer->buffer[buffer->curr++];
+		if (buffer->curr >= buffer->size)
+			buffer->stop = 1;
+		if (c == '\n')
+			break;
+		if (len > 1) {
+			len--;
+			*line++ = c;
+		}
+	}
+	*line = '\0';
+	return 0;
+}
+EXPORT_SYMBOL(snd_info_get_line);
+
+/**
+ * snd_info_get_str - parse a string token
+ * @dest: the buffer to store the string token
+ * @src: the original string
+ * @len: the max. length of token - 1
+ *
+ * Parses the original string and copy a token to the given
+ * string buffer.
+ *
+ * Return: The updated pointer of the original string so that
+ * it can be used for the next call.
+ */
+const char *snd_info_get_str(char *dest, const char *src, int len)
+{
+	int c;
+
+	while (*src == ' ' || *src == '\t')
+		src++;
+	if (*src == '"' || *src == '\'') {
+		c = *src++;
+		while (--len > 0 && *src && *src != c) {
+			*dest++ = *src++;
+		}
+		if (*src == c)
+			src++;
+	} else {
+		while (--len > 0 && *src && *src != ' ' && *src != '\t') {
+			*dest++ = *src++;
+		}
+	}
+	*dest = 0;
+	while (*src == ' ' || *src == '\t')
+		src++;
+	return src;
+}
+EXPORT_SYMBOL(snd_info_get_str);
+
+/*
+ * snd_info_create_entry - create an info entry
+ * @name: the proc file name
+ * @parent: the parent directory
+ *
+ * Creates an info entry with the given file name and initializes as
+ * the default state.
+ *
+ * Usually called from other functions such as
+ * snd_info_create_card_entry().
+ *
+ * Return: The pointer of the new instance, or %NULL on failure.
+ */
+static struct snd_info_entry *
+snd_info_create_entry(const char *name, struct snd_info_entry *parent,
+		      struct module *module)
+{
+	struct snd_info_entry *entry;
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (entry == NULL)
+		return NULL;
+	entry->name = kstrdup(name, GFP_KERNEL);
+	if (entry->name == NULL) {
+		kfree(entry);
+		return NULL;
+	}
+	entry->mode = S_IFREG | 0444;
+	entry->content = SNDRV_INFO_CONTENT_TEXT;
+	mutex_init(&entry->access);
+	INIT_LIST_HEAD(&entry->children);
+	INIT_LIST_HEAD(&entry->list);
+	entry->parent = parent;
+	entry->module = module;
+	if (parent) {
+		mutex_lock(&parent->access);
+		list_add_tail(&entry->list, &parent->children);
+		mutex_unlock(&parent->access);
+	}
+	return entry;
+}
+
+/**
+ * snd_info_create_module_entry - create an info entry for the given module
+ * @module: the module pointer
+ * @name: the file name
+ * @parent: the parent directory
+ *
+ * Creates a new info entry and assigns it to the given module.
+ *
+ * Return: The pointer of the new instance, or %NULL on failure.
+ */
+struct snd_info_entry *snd_info_create_module_entry(struct module * module,
+					       const char *name,
+					       struct snd_info_entry *parent)
+{
+	if (!parent)
+		parent = snd_proc_root;
+	return snd_info_create_entry(name, parent, module);
+}
+EXPORT_SYMBOL(snd_info_create_module_entry);
+
+/**
+ * snd_info_create_card_entry - create an info entry for the given card
+ * @card: the card instance
+ * @name: the file name
+ * @parent: the parent directory
+ *
+ * Creates a new info entry and assigns it to the given card.
+ *
+ * Return: The pointer of the new instance, or %NULL on failure.
+ */
+struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
+					     const char *name,
+					     struct snd_info_entry * parent)
+{
+	if (!parent)
+		parent = card->proc_root;
+	return snd_info_create_entry(name, parent, card->module);
+}
+EXPORT_SYMBOL(snd_info_create_card_entry);
+
+static void snd_info_clear_entries(struct snd_info_entry *entry)
+{
+	struct snd_info_entry *p;
+
+	if (!entry->p)
+		return;
+	list_for_each_entry(p, &entry->children, list)
+		snd_info_clear_entries(p);
+	entry->p = NULL;
+}
+
+/**
+ * snd_info_free_entry - release the info entry
+ * @entry: the info entry
+ *
+ * Releases the info entry.
+ */
+void snd_info_free_entry(struct snd_info_entry * entry)
+{
+	struct snd_info_entry *p, *n;
+
+	if (!entry)
+		return;
+	if (entry->p) {
+		proc_remove(entry->p);
+		mutex_lock(&info_mutex);
+		snd_info_clear_entries(entry);
+		mutex_unlock(&info_mutex);
+	}
+
+	/* free all children at first */
+	list_for_each_entry_safe(p, n, &entry->children, list)
+		snd_info_free_entry(p);
+
+	p = entry->parent;
+	if (p) {
+		mutex_lock(&p->access);
+		list_del(&entry->list);
+		mutex_unlock(&p->access);
+	}
+	kfree(entry->name);
+	if (entry->private_free)
+		entry->private_free(entry);
+	kfree(entry);
+}
+EXPORT_SYMBOL(snd_info_free_entry);
+
+static int __snd_info_register(struct snd_info_entry *entry)
+{
+	struct proc_dir_entry *root, *p = NULL;
+
+	if (snd_BUG_ON(!entry))
+		return -ENXIO;
+	root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
+	mutex_lock(&info_mutex);
+	if (entry->p || !root)
+		goto unlock;
+	if (S_ISDIR(entry->mode)) {
+		p = proc_mkdir_mode(entry->name, entry->mode, root);
+		if (!p) {
+			mutex_unlock(&info_mutex);
+			return -ENOMEM;
+		}
+	} else {
+		const struct proc_ops *ops;
+		if (entry->content == SNDRV_INFO_CONTENT_DATA)
+			ops = &snd_info_entry_operations;
+		else
+			ops = &snd_info_text_entry_ops;
+		p = proc_create_data(entry->name, entry->mode, root,
+				     ops, entry);
+		if (!p) {
+			mutex_unlock(&info_mutex);
+			return -ENOMEM;
+		}
+		proc_set_size(p, entry->size);
+	}
+	entry->p = p;
+ unlock:
+	mutex_unlock(&info_mutex);
+	return 0;
+}
+
+/**
+ * snd_info_register - register the info entry
+ * @entry: the info entry
+ *
+ * Registers the proc info entry.
+ * The all children entries are registered recursively.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_info_register(struct snd_info_entry *entry)
+{
+	struct snd_info_entry *p;
+	int err;
+
+	if (!entry->p) {
+		err = __snd_info_register(entry);
+		if (err < 0)
+			return err;
+	}
+
+	list_for_each_entry(p, &entry->children, list) {
+		err = snd_info_register(p);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(snd_info_register);
+
+/**
+ * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
+ * @card: the card instance
+ * @name: the file name
+ * @private_data: the arbitrary private data
+ * @read: the read callback
+ * @write: the write callback, NULL for read-only
+ *
+ * This proc file entry will be registered via snd_card_register() call, and
+ * it will be removed automatically at the card removal, too.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_card_rw_proc_new(struct snd_card *card, const char *name,
+			 void *private_data,
+			 void (*read)(struct snd_info_entry *,
+				      struct snd_info_buffer *),
+			 void (*write)(struct snd_info_entry *entry,
+				       struct snd_info_buffer *buffer))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(card, name, card->proc_root);
+	if (!entry)
+		return -ENOMEM;
+	snd_info_set_text_ops(entry, private_data, read);
+	if (write) {
+		entry->mode |= 0200;
+		entry->c.text.write = write;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
+
+/*
+
+ */
+
+static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
+{
+	snd_iprintf(buffer,
+		    "Advanced Linux Sound Architecture Driver Version k%s.\n",
+		    init_utsname()->release);
+}
+
+static int __init snd_info_version_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
+	if (entry == NULL)
+		return -ENOMEM;
+	entry->c.text.read = snd_info_version_read;
+	return snd_info_register(entry); /* freed in error path */
+}
diff --git a/sound/core/info_oss.c b/sound/core/info_oss.c
new file mode 100644
index 0000000000..ebc714b2f4
--- /dev/null
+++ b/sound/core/info_oss.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Information interface for ALSA driver
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/info.h>
+#include <linux/utsname.h>
+#include <linux/mutex.h>
+
+/*
+ *  OSS compatible part
+ */
+
+static DEFINE_MUTEX(strings);
+static char *snd_sndstat_strings[SNDRV_CARDS][SNDRV_OSS_INFO_DEV_COUNT];
+
+int snd_oss_info_register(int dev, int num, char *string)
+{
+	char *x;
+
+	if (snd_BUG_ON(dev < 0 || dev >= SNDRV_OSS_INFO_DEV_COUNT))
+		return -ENXIO;
+	if (snd_BUG_ON(num < 0 || num >= SNDRV_CARDS))
+		return -ENXIO;
+	mutex_lock(&strings);
+	if (string == NULL) {
+		x = snd_sndstat_strings[num][dev];
+		kfree(x);
+		x = NULL;
+	} else {
+		x = kstrdup(string, GFP_KERNEL);
+		if (x == NULL) {
+			mutex_unlock(&strings);
+			return -ENOMEM;
+		}
+	}
+	snd_sndstat_strings[num][dev] = x;
+	mutex_unlock(&strings);
+	return 0;
+}
+EXPORT_SYMBOL(snd_oss_info_register);
+
+static int snd_sndstat_show_strings(struct snd_info_buffer *buf, char *id, int dev)
+{
+	int idx, ok = -1;
+	char *str;
+
+	snd_iprintf(buf, "\n%s:", id);
+	mutex_lock(&strings);
+	for (idx = 0; idx < SNDRV_CARDS; idx++) {
+		str = snd_sndstat_strings[idx][dev];
+		if (str) {
+			if (ok < 0) {
+				snd_iprintf(buf, "\n");
+				ok++;
+			}
+			snd_iprintf(buf, "%i: %s\n", idx, str);
+		}
+	}
+	mutex_unlock(&strings);
+	if (ok < 0)
+		snd_iprintf(buf, " NOT ENABLED IN CONFIG\n");
+	return ok;
+}
+
+static void snd_sndstat_proc_read(struct snd_info_entry *entry,
+				  struct snd_info_buffer *buffer)
+{
+	snd_iprintf(buffer, "Sound Driver:3.8.1a-980706 (ALSA emulation code)\n");
+	snd_iprintf(buffer, "Kernel: %s %s %s %s %s\n",
+		    init_utsname()->sysname,
+		    init_utsname()->nodename,
+		    init_utsname()->release,
+		    init_utsname()->version,
+		    init_utsname()->machine);
+	snd_iprintf(buffer, "Config options: 0\n");
+	snd_iprintf(buffer, "\nInstalled drivers: \n");
+	snd_iprintf(buffer, "Type 10: ALSA emulation\n");
+	snd_iprintf(buffer, "\nCard config: \n");
+	snd_card_info_read_oss(buffer);
+	snd_sndstat_show_strings(buffer, "Audio devices", SNDRV_OSS_INFO_DEV_AUDIO);
+	snd_sndstat_show_strings(buffer, "Synth devices", SNDRV_OSS_INFO_DEV_SYNTH);
+	snd_sndstat_show_strings(buffer, "Midi devices", SNDRV_OSS_INFO_DEV_MIDI);
+	snd_sndstat_show_strings(buffer, "Timers", SNDRV_OSS_INFO_DEV_TIMERS);
+	snd_sndstat_show_strings(buffer, "Mixers", SNDRV_OSS_INFO_DEV_MIXERS);
+}
+
+int __init snd_info_minor_register(void)
+{
+	struct snd_info_entry *entry;
+
+	memset(snd_sndstat_strings, 0, sizeof(snd_sndstat_strings));
+	entry = snd_info_create_module_entry(THIS_MODULE, "sndstat",
+					     snd_oss_root);
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_sndstat_proc_read;
+	return snd_info_register(entry); /* freed in error path */
+}
diff --git a/sound/core/init.c b/sound/core/init.c
new file mode 100644
index 0000000000..22c0d217b8
--- /dev/null
+++ b/sound/core/init.c
@@ -0,0 +1,1177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Initialization routines
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/ctype.h>
+#include <linux/pm.h>
+#include <linux/debugfs.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/info.h>
+
+/* monitor files for graceful shutdown (hotplug) */
+struct snd_monitor_file {
+	struct file *file;
+	const struct file_operations *disconnected_f_op;
+	struct list_head shutdown_list;	/* still need to shutdown */
+	struct list_head list;	/* link of monitor files */
+};
+
+static DEFINE_SPINLOCK(shutdown_lock);
+static LIST_HEAD(shutdown_files);
+
+static const struct file_operations snd_shutdown_f_ops;
+
+/* locked for registering/using */
+static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
+static struct snd_card *snd_cards[SNDRV_CARDS];
+
+static DEFINE_MUTEX(snd_card_mutex);
+
+static char *slots[SNDRV_CARDS];
+module_param_array(slots, charp, NULL, 0444);
+MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
+
+/* return non-zero if the given index is reserved for the given
+ * module via slots option
+ */
+static int module_slot_match(struct module *module, int idx)
+{
+	int match = 1;
+#ifdef MODULE
+	const char *s1, *s2;
+
+	if (!module || !*module->name || !slots[idx])
+		return 0;
+
+	s1 = module->name;
+	s2 = slots[idx];
+	if (*s2 == '!') {
+		match = 0; /* negative match */
+		s2++;
+	}
+	/* compare module name strings
+	 * hyphens are handled as equivalent with underscore
+	 */
+	for (;;) {
+		char c1 = *s1++;
+		char c2 = *s2++;
+		if (c1 == '-')
+			c1 = '_';
+		if (c2 == '-')
+			c2 = '_';
+		if (c1 != c2)
+			return !match;
+		if (!c1)
+			break;
+	}
+#endif /* MODULE */
+	return match;
+}
+
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
+int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
+EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
+#endif
+
+static int check_empty_slot(struct module *module, int slot)
+{
+	return !slots[slot] || !*slots[slot];
+}
+
+/* return an empty slot number (>= 0) found in the given bitmask @mask.
+ * @mask == -1 == 0xffffffff means: take any free slot up to 32
+ * when no slot is available, return the original @mask as is.
+ */
+static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
+				 struct module *module)
+{
+	int slot;
+
+	for (slot = 0; slot < SNDRV_CARDS; slot++) {
+		if (slot < 32 && !(mask & (1U << slot)))
+			continue;
+		if (!test_bit(slot, snd_cards_lock)) {
+			if (check(module, slot))
+				return slot; /* found */
+		}
+	}
+	return mask; /* unchanged */
+}
+
+/* the default release callback set in snd_device_alloc() */
+static void default_release_alloc(struct device *dev)
+{
+	kfree(dev);
+}
+
+/**
+ * snd_device_alloc - Allocate and initialize struct device for sound devices
+ * @dev_p: pointer to store the allocated device
+ * @card: card to assign, optional
+ *
+ * For releasing the allocated device, call put_device().
+ */
+int snd_device_alloc(struct device **dev_p, struct snd_card *card)
+{
+	struct device *dev;
+
+	*dev_p = NULL;
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	device_initialize(dev);
+	if (card)
+		dev->parent = &card->card_dev;
+	dev->class = &sound_class;
+	dev->release = default_release_alloc;
+	*dev_p = dev;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_device_alloc);
+
+static int snd_card_init(struct snd_card *card, struct device *parent,
+			 int idx, const char *xid, struct module *module,
+			 size_t extra_size);
+static int snd_card_do_free(struct snd_card *card);
+static const struct attribute_group card_dev_attr_group;
+
+static void release_card_device(struct device *dev)
+{
+	snd_card_do_free(dev_to_snd_card(dev));
+}
+
+/**
+ *  snd_card_new - create and initialize a soundcard structure
+ *  @parent: the parent device object
+ *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
+ *  @xid: card identification (ASCII string)
+ *  @module: top level module for locking
+ *  @extra_size: allocate this extra size after the main soundcard structure
+ *  @card_ret: the pointer to store the created card instance
+ *
+ *  The function allocates snd_card instance via kzalloc with the given
+ *  space for the driver to use freely.  The allocated struct is stored
+ *  in the given card_ret pointer.
+ *
+ *  Return: Zero if successful or a negative error code.
+ */
+int snd_card_new(struct device *parent, int idx, const char *xid,
+		    struct module *module, int extra_size,
+		    struct snd_card **card_ret)
+{
+	struct snd_card *card;
+	int err;
+
+	if (snd_BUG_ON(!card_ret))
+		return -EINVAL;
+	*card_ret = NULL;
+
+	if (extra_size < 0)
+		extra_size = 0;
+	card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
+	if (!card)
+		return -ENOMEM;
+
+	err = snd_card_init(card, parent, idx, xid, module, extra_size);
+	if (err < 0)
+		return err; /* card is freed by error handler */
+
+	*card_ret = card;
+	return 0;
+}
+EXPORT_SYMBOL(snd_card_new);
+
+static void __snd_card_release(struct device *dev, void *data)
+{
+	snd_card_free(data);
+}
+
+/**
+ * snd_devm_card_new - managed snd_card object creation
+ * @parent: the parent device object
+ * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
+ * @xid: card identification (ASCII string)
+ * @module: top level module for locking
+ * @extra_size: allocate this extra size after the main soundcard structure
+ * @card_ret: the pointer to store the created card instance
+ *
+ * This function works like snd_card_new() but manages the allocated resource
+ * via devres, i.e. you don't need to free explicitly.
+ *
+ * When a snd_card object is created with this function and registered via
+ * snd_card_register(), the very first devres action to call snd_card_free()
+ * is added automatically.  In that way, the resource disconnection is assured
+ * at first, then released in the expected order.
+ *
+ * If an error happens at the probe before snd_card_register() is called and
+ * there have been other devres resources, you'd need to free the card manually
+ * via snd_card_free() call in the error; otherwise it may lead to UAF due to
+ * devres call orders.  You can use snd_card_free_on_error() helper for
+ * handling it more easily.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_devm_card_new(struct device *parent, int idx, const char *xid,
+		      struct module *module, size_t extra_size,
+		      struct snd_card **card_ret)
+{
+	struct snd_card *card;
+	int err;
+
+	*card_ret = NULL;
+	card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
+			    GFP_KERNEL);
+	if (!card)
+		return -ENOMEM;
+	card->managed = true;
+	err = snd_card_init(card, parent, idx, xid, module, extra_size);
+	if (err < 0) {
+		devres_free(card); /* in managed mode, we need to free manually */
+		return err;
+	}
+
+	devres_add(parent, card);
+	*card_ret = card;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_devm_card_new);
+
+/**
+ * snd_card_free_on_error - a small helper for handling devm probe errors
+ * @dev: the managed device object
+ * @ret: the return code from the probe callback
+ *
+ * This function handles the explicit snd_card_free() call at the error from
+ * the probe callback.  It's just a small helper for simplifying the error
+ * handling with the managed devices.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_card_free_on_error(struct device *dev, int ret)
+{
+	struct snd_card *card;
+
+	if (!ret)
+		return 0;
+	card = devres_find(dev, __snd_card_release, NULL, NULL);
+	if (card)
+		snd_card_free(card);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_card_free_on_error);
+
+static int snd_card_init(struct snd_card *card, struct device *parent,
+			 int idx, const char *xid, struct module *module,
+			 size_t extra_size)
+{
+	int err;
+
+	if (extra_size > 0)
+		card->private_data = (char *)card + sizeof(struct snd_card);
+	if (xid)
+		strscpy(card->id, xid, sizeof(card->id));
+	err = 0;
+	mutex_lock(&snd_card_mutex);
+	if (idx < 0) /* first check the matching module-name slot */
+		idx = get_slot_from_bitmask(idx, module_slot_match, module);
+	if (idx < 0) /* if not matched, assign an empty slot */
+		idx = get_slot_from_bitmask(idx, check_empty_slot, module);
+	if (idx < 0)
+		err = -ENODEV;
+	else if (idx < snd_ecards_limit) {
+		if (test_bit(idx, snd_cards_lock))
+			err = -EBUSY;	/* invalid */
+	} else if (idx >= SNDRV_CARDS)
+		err = -ENODEV;
+	if (err < 0) {
+		mutex_unlock(&snd_card_mutex);
+		dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
+			 idx, snd_ecards_limit - 1, err);
+		if (!card->managed)
+			kfree(card); /* manually free here, as no destructor called */
+		return err;
+	}
+	set_bit(idx, snd_cards_lock);		/* lock it */
+	if (idx >= snd_ecards_limit)
+		snd_ecards_limit = idx + 1; /* increase the limit */
+	mutex_unlock(&snd_card_mutex);
+	card->dev = parent;
+	card->number = idx;
+#ifdef MODULE
+	WARN_ON(!module);
+	card->module = module;
+#endif
+	INIT_LIST_HEAD(&card->devices);
+	init_rwsem(&card->controls_rwsem);
+	rwlock_init(&card->ctl_files_rwlock);
+	INIT_LIST_HEAD(&card->controls);
+	INIT_LIST_HEAD(&card->ctl_files);
+#ifdef CONFIG_SND_CTL_FAST_LOOKUP
+	xa_init(&card->ctl_numids);
+	xa_init(&card->ctl_hash);
+#endif
+	spin_lock_init(&card->files_lock);
+	INIT_LIST_HEAD(&card->files_list);
+	mutex_init(&card->memory_mutex);
+#ifdef CONFIG_PM
+	init_waitqueue_head(&card->power_sleep);
+	init_waitqueue_head(&card->power_ref_sleep);
+	atomic_set(&card->power_ref, 0);
+#endif
+	init_waitqueue_head(&card->remove_sleep);
+	card->sync_irq = -1;
+
+	device_initialize(&card->card_dev);
+	card->card_dev.parent = parent;
+	card->card_dev.class = &sound_class;
+	card->card_dev.release = release_card_device;
+	card->card_dev.groups = card->dev_groups;
+	card->dev_groups[0] = &card_dev_attr_group;
+	err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
+	if (err < 0)
+		goto __error;
+
+	snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
+		 dev_driver_string(card->dev), dev_name(&card->card_dev));
+
+	/* the control interface cannot be accessed from the user space until */
+	/* snd_cards_bitmask and snd_cards are set with snd_card_register */
+	err = snd_ctl_create(card);
+	if (err < 0) {
+		dev_err(parent, "unable to register control minors\n");
+		goto __error;
+	}
+	err = snd_info_card_create(card);
+	if (err < 0) {
+		dev_err(parent, "unable to create card info\n");
+		goto __error_ctl;
+	}
+
+#ifdef CONFIG_SND_DEBUG
+	card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),
+						sound_debugfs_root);
+#endif
+	return 0;
+
+      __error_ctl:
+	snd_device_free_all(card);
+      __error:
+	put_device(&card->card_dev);
+  	return err;
+}
+
+/**
+ * snd_card_ref - Get the card object from the index
+ * @idx: the card index
+ *
+ * Returns a card object corresponding to the given index or NULL if not found.
+ * Release the object via snd_card_unref().
+ *
+ * Return: a card object or NULL
+ */
+struct snd_card *snd_card_ref(int idx)
+{
+	struct snd_card *card;
+
+	mutex_lock(&snd_card_mutex);
+	card = snd_cards[idx];
+	if (card)
+		get_device(&card->card_dev);
+	mutex_unlock(&snd_card_mutex);
+	return card;
+}
+EXPORT_SYMBOL_GPL(snd_card_ref);
+
+/* return non-zero if a card is already locked */
+int snd_card_locked(int card)
+{
+	int locked;
+
+	mutex_lock(&snd_card_mutex);
+	locked = test_bit(card, snd_cards_lock);
+	mutex_unlock(&snd_card_mutex);
+	return locked;
+}
+
+static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
+{
+	return -ENODEV;
+}
+
+static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
+				   size_t count, loff_t *offset)
+{
+	return -ENODEV;
+}
+
+static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
+				    size_t count, loff_t *offset)
+{
+	return -ENODEV;
+}
+
+static int snd_disconnect_release(struct inode *inode, struct file *file)
+{
+	struct snd_monitor_file *df = NULL, *_df;
+
+	spin_lock(&shutdown_lock);
+	list_for_each_entry(_df, &shutdown_files, shutdown_list) {
+		if (_df->file == file) {
+			df = _df;
+			list_del_init(&df->shutdown_list);
+			break;
+		}
+	}
+	spin_unlock(&shutdown_lock);
+
+	if (likely(df)) {
+		if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
+			df->disconnected_f_op->fasync(-1, file, 0);
+		return df->disconnected_f_op->release(inode, file);
+	}
+
+	panic("%s(%p, %p) failed!", __func__, inode, file);
+}
+
+static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
+{
+	return EPOLLERR | EPOLLNVAL;
+}
+
+static long snd_disconnect_ioctl(struct file *file,
+				 unsigned int cmd, unsigned long arg)
+{
+	return -ENODEV;
+}
+
+static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	return -ENODEV;
+}
+
+static int snd_disconnect_fasync(int fd, struct file *file, int on)
+{
+	return -ENODEV;
+}
+
+static const struct file_operations snd_shutdown_f_ops =
+{
+	.owner = 	THIS_MODULE,
+	.llseek =	snd_disconnect_llseek,
+	.read = 	snd_disconnect_read,
+	.write =	snd_disconnect_write,
+	.release =	snd_disconnect_release,
+	.poll =		snd_disconnect_poll,
+	.unlocked_ioctl = snd_disconnect_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = snd_disconnect_ioctl,
+#endif
+	.mmap =		snd_disconnect_mmap,
+	.fasync =	snd_disconnect_fasync
+};
+
+/**
+ *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
+ *  @card: soundcard structure
+ *
+ *  Disconnects all APIs from the file-operations (user space).
+ *
+ *  Return: Zero, otherwise a negative error code.
+ *
+ *  Note: The current implementation replaces all active file->f_op with special
+ *        dummy file operations (they do nothing except release).
+ */
+void snd_card_disconnect(struct snd_card *card)
+{
+	struct snd_monitor_file *mfile;
+
+	if (!card)
+		return;
+
+	spin_lock(&card->files_lock);
+	if (card->shutdown) {
+		spin_unlock(&card->files_lock);
+		return;
+	}
+	card->shutdown = 1;
+
+	/* replace file->f_op with special dummy operations */
+	list_for_each_entry(mfile, &card->files_list, list) {
+		/* it's critical part, use endless loop */
+		/* we have no room to fail */
+		mfile->disconnected_f_op = mfile->file->f_op;
+
+		spin_lock(&shutdown_lock);
+		list_add(&mfile->shutdown_list, &shutdown_files);
+		spin_unlock(&shutdown_lock);
+
+		mfile->file->f_op = &snd_shutdown_f_ops;
+		fops_get(mfile->file->f_op);
+	}
+	spin_unlock(&card->files_lock);	
+
+	/* notify all connected devices about disconnection */
+	/* at this point, they cannot respond to any calls except release() */
+
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
+	if (snd_mixer_oss_notify_callback)
+		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
+#endif
+
+	/* notify all devices that we are disconnected */
+	snd_device_disconnect_all(card);
+
+	if (card->sync_irq > 0)
+		synchronize_irq(card->sync_irq);
+
+	snd_info_card_disconnect(card);
+	if (card->registered) {
+		device_del(&card->card_dev);
+		card->registered = false;
+	}
+
+	/* disable fops (user space) operations for ALSA API */
+	mutex_lock(&snd_card_mutex);
+	snd_cards[card->number] = NULL;
+	clear_bit(card->number, snd_cards_lock);
+	mutex_unlock(&snd_card_mutex);
+
+#ifdef CONFIG_PM
+	wake_up(&card->power_sleep);
+	snd_power_sync_ref(card);
+#endif
+}
+EXPORT_SYMBOL(snd_card_disconnect);
+
+/**
+ * snd_card_disconnect_sync - disconnect card and wait until files get closed
+ * @card: card object to disconnect
+ *
+ * This calls snd_card_disconnect() for disconnecting all belonging components
+ * and waits until all pending files get closed.
+ * It assures that all accesses from user-space finished so that the driver
+ * can release its resources gracefully.
+ */
+void snd_card_disconnect_sync(struct snd_card *card)
+{
+	snd_card_disconnect(card);
+
+	spin_lock_irq(&card->files_lock);
+	wait_event_lock_irq(card->remove_sleep,
+			    list_empty(&card->files_list),
+			    card->files_lock);
+	spin_unlock_irq(&card->files_lock);
+}
+EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
+
+static int snd_card_do_free(struct snd_card *card)
+{
+	card->releasing = true;
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
+	if (snd_mixer_oss_notify_callback)
+		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
+#endif
+	snd_device_free_all(card);
+	if (card->private_free)
+		card->private_free(card);
+	if (snd_info_card_free(card) < 0) {
+		dev_warn(card->dev, "unable to free card info\n");
+		/* Not fatal error */
+	}
+#ifdef CONFIG_SND_DEBUG
+	debugfs_remove(card->debugfs_root);
+	card->debugfs_root = NULL;
+#endif
+	if (card->release_completion)
+		complete(card->release_completion);
+	if (!card->managed)
+		kfree(card);
+	return 0;
+}
+
+/**
+ * snd_card_free_when_closed - Disconnect the card, free it later eventually
+ * @card: soundcard structure
+ *
+ * Unlike snd_card_free(), this function doesn't try to release the card
+ * resource immediately, but tries to disconnect at first.  When the card
+ * is still in use, the function returns before freeing the resources.
+ * The card resources will be freed when the refcount gets to zero.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+void snd_card_free_when_closed(struct snd_card *card)
+{
+	if (!card)
+		return;
+
+	snd_card_disconnect(card);
+	put_device(&card->card_dev);
+	return;
+}
+EXPORT_SYMBOL(snd_card_free_when_closed);
+
+/**
+ * snd_card_free - frees given soundcard structure
+ * @card: soundcard structure
+ *
+ * This function releases the soundcard structure and the all assigned
+ * devices automatically.  That is, you don't have to release the devices
+ * by yourself.
+ *
+ * This function waits until the all resources are properly released.
+ *
+ * Return: Zero. Frees all associated devices and frees the control
+ * interface associated to given soundcard.
+ */
+void snd_card_free(struct snd_card *card)
+{
+	DECLARE_COMPLETION_ONSTACK(released);
+
+	/* The call of snd_card_free() is allowed from various code paths;
+	 * a manual call from the driver and the call via devres_free, and
+	 * we need to avoid double-free. Moreover, the release via devres
+	 * may call snd_card_free() twice due to its nature, we need to have
+	 * the check here at the beginning.
+	 */
+	if (card->releasing)
+		return;
+
+	card->release_completion = &released;
+	snd_card_free_when_closed(card);
+
+	/* wait, until all devices are ready for the free operation */
+	wait_for_completion(&released);
+}
+EXPORT_SYMBOL(snd_card_free);
+
+/* retrieve the last word of shortname or longname */
+static const char *retrieve_id_from_card_name(const char *name)
+{
+	const char *spos = name;
+
+	while (*name) {
+		if (isspace(*name) && isalnum(name[1]))
+			spos = name + 1;
+		name++;
+	}
+	return spos;
+}
+
+/* return true if the given id string doesn't conflict any other card ids */
+static bool card_id_ok(struct snd_card *card, const char *id)
+{
+	int i;
+	if (!snd_info_check_reserved_words(id))
+		return false;
+	for (i = 0; i < snd_ecards_limit; i++) {
+		if (snd_cards[i] && snd_cards[i] != card &&
+		    !strcmp(snd_cards[i]->id, id))
+			return false;
+	}
+	return true;
+}
+
+/* copy to card->id only with valid letters from nid */
+static void copy_valid_id_string(struct snd_card *card, const char *src,
+				 const char *nid)
+{
+	char *id = card->id;
+
+	while (*nid && !isalnum(*nid))
+		nid++;
+	if (isdigit(*nid))
+		*id++ = isalpha(*src) ? *src : 'D';
+	while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
+		if (isalnum(*nid))
+			*id++ = *nid;
+		nid++;
+	}
+	*id = 0;
+}
+
+/* Set card->id from the given string
+ * If the string conflicts with other ids, add a suffix to make it unique.
+ */
+static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
+				    const char *nid)
+{
+	int len, loops;
+	bool is_default = false;
+	char *id;
+	
+	copy_valid_id_string(card, src, nid);
+	id = card->id;
+
+ again:
+	/* use "Default" for obviously invalid strings
+	 * ("card" conflicts with proc directories)
+	 */
+	if (!*id || !strncmp(id, "card", 4)) {
+		strcpy(id, "Default");
+		is_default = true;
+	}
+
+	len = strlen(id);
+	for (loops = 0; loops < SNDRV_CARDS; loops++) {
+		char *spos;
+		char sfxstr[5]; /* "_012" */
+		int sfxlen;
+
+		if (card_id_ok(card, id))
+			return; /* OK */
+
+		/* Add _XYZ suffix */
+		sprintf(sfxstr, "_%X", loops + 1);
+		sfxlen = strlen(sfxstr);
+		if (len + sfxlen >= sizeof(card->id))
+			spos = id + sizeof(card->id) - sfxlen - 1;
+		else
+			spos = id + len;
+		strcpy(spos, sfxstr);
+	}
+	/* fallback to the default id */
+	if (!is_default) {
+		*id = 0;
+		goto again;
+	}
+	/* last resort... */
+	dev_err(card->dev, "unable to set card id (%s)\n", id);
+	if (card->proc_root->name)
+		strscpy(card->id, card->proc_root->name, sizeof(card->id));
+}
+
+/**
+ *  snd_card_set_id - set card identification name
+ *  @card: soundcard structure
+ *  @nid: new identification string
+ *
+ *  This function sets the card identification and checks for name
+ *  collisions.
+ */
+void snd_card_set_id(struct snd_card *card, const char *nid)
+{
+	/* check if user specified own card->id */
+	if (card->id[0] != '\0')
+		return;
+	mutex_lock(&snd_card_mutex);
+	snd_card_set_id_no_lock(card, nid, nid);
+	mutex_unlock(&snd_card_mutex);
+}
+EXPORT_SYMBOL(snd_card_set_id);
+
+static ssize_t id_show(struct device *dev,
+		       struct device_attribute *attr, char *buf)
+{
+	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+	return sysfs_emit(buf, "%s\n", card->id);
+}
+
+static ssize_t id_store(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+	char buf1[sizeof(card->id)];
+	size_t copy = count > sizeof(card->id) - 1 ?
+					sizeof(card->id) - 1 : count;
+	size_t idx;
+	int c;
+
+	for (idx = 0; idx < copy; idx++) {
+		c = buf[idx];
+		if (!isalnum(c) && c != '_' && c != '-')
+			return -EINVAL;
+	}
+	memcpy(buf1, buf, copy);
+	buf1[copy] = '\0';
+	mutex_lock(&snd_card_mutex);
+	if (!card_id_ok(NULL, buf1)) {
+		mutex_unlock(&snd_card_mutex);
+		return -EEXIST;
+	}
+	strcpy(card->id, buf1);
+	snd_info_card_id_change(card);
+	mutex_unlock(&snd_card_mutex);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(id);
+
+static ssize_t number_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+	return sysfs_emit(buf, "%i\n", card->number);
+}
+
+static DEVICE_ATTR_RO(number);
+
+static struct attribute *card_dev_attrs[] = {
+	&dev_attr_id.attr,
+	&dev_attr_number.attr,
+	NULL
+};
+
+static const struct attribute_group card_dev_attr_group = {
+	.attrs	= card_dev_attrs,
+};
+
+/**
+ * snd_card_add_dev_attr - Append a new sysfs attribute group to card
+ * @card: card instance
+ * @group: attribute group to append
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_card_add_dev_attr(struct snd_card *card,
+			  const struct attribute_group *group)
+{
+	int i;
+
+	/* loop for (arraysize-1) here to keep NULL at the last entry */
+	for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
+		if (!card->dev_groups[i]) {
+			card->dev_groups[i] = group;
+			return 0;
+		}
+	}
+
+	dev_err(card->dev, "Too many groups assigned\n");
+	return -ENOSPC;
+}
+EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
+
+static void trigger_card_free(void *data)
+{
+	snd_card_free(data);
+}
+
+/**
+ *  snd_card_register - register the soundcard
+ *  @card: soundcard structure
+ *
+ *  This function registers all the devices assigned to the soundcard.
+ *  Until calling this, the ALSA control interface is blocked from the
+ *  external accesses.  Thus, you should call this function at the end
+ *  of the initialization of the card.
+ *
+ *  Return: Zero otherwise a negative error code if the registration failed.
+ */
+int snd_card_register(struct snd_card *card)
+{
+	int err;
+
+	if (snd_BUG_ON(!card))
+		return -EINVAL;
+
+	if (!card->registered) {
+		err = device_add(&card->card_dev);
+		if (err < 0)
+			return err;
+		card->registered = true;
+	} else {
+		if (card->managed)
+			devm_remove_action(card->dev, trigger_card_free, card);
+	}
+
+	if (card->managed) {
+		err = devm_add_action(card->dev, trigger_card_free, card);
+		if (err < 0)
+			return err;
+	}
+
+	err = snd_device_register_all(card);
+	if (err < 0)
+		return err;
+	mutex_lock(&snd_card_mutex);
+	if (snd_cards[card->number]) {
+		/* already registered */
+		mutex_unlock(&snd_card_mutex);
+		return snd_info_card_register(card); /* register pending info */
+	}
+	if (*card->id) {
+		/* make a unique id name from the given string */
+		char tmpid[sizeof(card->id)];
+		memcpy(tmpid, card->id, sizeof(card->id));
+		snd_card_set_id_no_lock(card, tmpid, tmpid);
+	} else {
+		/* create an id from either shortname or longname */
+		const char *src;
+		src = *card->shortname ? card->shortname : card->longname;
+		snd_card_set_id_no_lock(card, src,
+					retrieve_id_from_card_name(src));
+	}
+	snd_cards[card->number] = card;
+	mutex_unlock(&snd_card_mutex);
+	err = snd_info_card_register(card);
+	if (err < 0)
+		return err;
+
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
+	if (snd_mixer_oss_notify_callback)
+		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
+#endif
+	return 0;
+}
+EXPORT_SYMBOL(snd_card_register);
+
+#ifdef CONFIG_SND_PROC_FS
+static void snd_card_info_read(struct snd_info_entry *entry,
+			       struct snd_info_buffer *buffer)
+{
+	int idx, count;
+	struct snd_card *card;
+
+	for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
+		mutex_lock(&snd_card_mutex);
+		card = snd_cards[idx];
+		if (card) {
+			count++;
+			snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
+					idx,
+					card->id,
+					card->driver,
+					card->shortname);
+			snd_iprintf(buffer, "                      %s\n",
+					card->longname);
+		}
+		mutex_unlock(&snd_card_mutex);
+	}
+	if (!count)
+		snd_iprintf(buffer, "--- no soundcards ---\n");
+}
+
+#ifdef CONFIG_SND_OSSEMUL
+void snd_card_info_read_oss(struct snd_info_buffer *buffer)
+{
+	int idx, count;
+	struct snd_card *card;
+
+	for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
+		mutex_lock(&snd_card_mutex);
+		card = snd_cards[idx];
+		if (card) {
+			count++;
+			snd_iprintf(buffer, "%s\n", card->longname);
+		}
+		mutex_unlock(&snd_card_mutex);
+	}
+	if (!count) {
+		snd_iprintf(buffer, "--- no soundcards ---\n");
+	}
+}
+
+#endif
+
+#ifdef MODULE
+static void snd_card_module_info_read(struct snd_info_entry *entry,
+				      struct snd_info_buffer *buffer)
+{
+	int idx;
+	struct snd_card *card;
+
+	for (idx = 0; idx < SNDRV_CARDS; idx++) {
+		mutex_lock(&snd_card_mutex);
+		card = snd_cards[idx];
+		if (card)
+			snd_iprintf(buffer, "%2i %s\n",
+				    idx, card->module->name);
+		mutex_unlock(&snd_card_mutex);
+	}
+}
+#endif
+
+int __init snd_card_info_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
+	if (! entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_card_info_read;
+	if (snd_info_register(entry) < 0)
+		return -ENOMEM; /* freed in error path */
+
+#ifdef MODULE
+	entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_card_module_info_read;
+	if (snd_info_register(entry) < 0)
+		return -ENOMEM; /* freed in error path */
+#endif
+
+	return 0;
+}
+#endif /* CONFIG_SND_PROC_FS */
+
+/**
+ *  snd_component_add - add a component string
+ *  @card: soundcard structure
+ *  @component: the component id string
+ *
+ *  This function adds the component id string to the supported list.
+ *  The component can be referred from the alsa-lib.
+ *
+ *  Return: Zero otherwise a negative error code.
+ */
+  
+int snd_component_add(struct snd_card *card, const char *component)
+{
+	char *ptr;
+	int len = strlen(component);
+
+	ptr = strstr(card->components, component);
+	if (ptr != NULL) {
+		if (ptr[len] == '\0' || ptr[len] == ' ')	/* already there */
+			return 1;
+	}
+	if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
+		snd_BUG();
+		return -ENOMEM;
+	}
+	if (card->components[0] != '\0')
+		strcat(card->components, " ");
+	strcat(card->components, component);
+	return 0;
+}
+EXPORT_SYMBOL(snd_component_add);
+
+/**
+ *  snd_card_file_add - add the file to the file list of the card
+ *  @card: soundcard structure
+ *  @file: file pointer
+ *
+ *  This function adds the file to the file linked-list of the card.
+ *  This linked-list is used to keep tracking the connection state,
+ *  and to avoid the release of busy resources by hotplug.
+ *
+ *  Return: zero or a negative error code.
+ */
+int snd_card_file_add(struct snd_card *card, struct file *file)
+{
+	struct snd_monitor_file *mfile;
+
+	mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
+	if (mfile == NULL)
+		return -ENOMEM;
+	mfile->file = file;
+	mfile->disconnected_f_op = NULL;
+	INIT_LIST_HEAD(&mfile->shutdown_list);
+	spin_lock(&card->files_lock);
+	if (card->shutdown) {
+		spin_unlock(&card->files_lock);
+		kfree(mfile);
+		return -ENODEV;
+	}
+	list_add(&mfile->list, &card->files_list);
+	get_device(&card->card_dev);
+	spin_unlock(&card->files_lock);
+	return 0;
+}
+EXPORT_SYMBOL(snd_card_file_add);
+
+/**
+ *  snd_card_file_remove - remove the file from the file list
+ *  @card: soundcard structure
+ *  @file: file pointer
+ *
+ *  This function removes the file formerly added to the card via
+ *  snd_card_file_add() function.
+ *  If all files are removed and snd_card_free_when_closed() was
+ *  called beforehand, it processes the pending release of
+ *  resources.
+ *
+ *  Return: Zero or a negative error code.
+ */
+int snd_card_file_remove(struct snd_card *card, struct file *file)
+{
+	struct snd_monitor_file *mfile, *found = NULL;
+
+	spin_lock(&card->files_lock);
+	list_for_each_entry(mfile, &card->files_list, list) {
+		if (mfile->file == file) {
+			list_del(&mfile->list);
+			spin_lock(&shutdown_lock);
+			list_del(&mfile->shutdown_list);
+			spin_unlock(&shutdown_lock);
+			if (mfile->disconnected_f_op)
+				fops_put(mfile->disconnected_f_op);
+			found = mfile;
+			break;
+		}
+	}
+	if (list_empty(&card->files_list))
+		wake_up_all(&card->remove_sleep);
+	spin_unlock(&card->files_lock);
+	if (!found) {
+		dev_err(card->dev, "card file remove problem (%p)\n", file);
+		return -ENOENT;
+	}
+	kfree(found);
+	put_device(&card->card_dev);
+	return 0;
+}
+EXPORT_SYMBOL(snd_card_file_remove);
+
+#ifdef CONFIG_PM
+/**
+ * snd_power_ref_and_wait - wait until the card gets powered up
+ * @card: soundcard structure
+ *
+ * Take the power_ref reference count of the given card, and
+ * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
+ * The refcount is down again while sleeping until power-up, hence this
+ * function can be used for syncing the floating control ops accesses,
+ * typically around calling control ops.
+ *
+ * The caller needs to pull down the refcount via snd_power_unref() later
+ * no matter whether the error is returned from this function or not.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_power_ref_and_wait(struct snd_card *card)
+{
+	snd_power_ref(card);
+	if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
+		return 0;
+	wait_event_cmd(card->power_sleep,
+		       card->shutdown ||
+		       snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
+		       snd_power_unref(card), snd_power_ref(card));
+	return card->shutdown ? -ENODEV : 0;
+}
+EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
+
+/**
+ * snd_power_wait - wait until the card gets powered up (old form)
+ * @card: soundcard structure
+ *
+ * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_power_wait(struct snd_card *card)
+{
+	int ret;
+
+	ret = snd_power_ref_and_wait(card);
+	snd_power_unref(card);
+	return ret;
+}
+EXPORT_SYMBOL(snd_power_wait);
+#endif /* CONFIG_PM */
diff --git a/sound/core/isadma.c b/sound/core/isadma.c
new file mode 100644
index 0000000000..28768061d7
--- /dev/null
+++ b/sound/core/isadma.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  ISA DMA support functions
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+/*
+ * Defining following add some delay. Maybe this helps for some broken
+ * ISA DMA controllers.
+ */
+
+#undef HAVE_REALLY_SLOW_DMA_CONTROLLER
+
+#include <linux/export.h>
+#include <linux/isa-dma.h>
+#include <sound/core.h>
+
+/**
+ * snd_dma_program - program an ISA DMA transfer
+ * @dma: the dma number
+ * @addr: the physical address of the buffer
+ * @size: the DMA transfer size
+ * @mode: the DMA transfer mode, DMA_MODE_XXX
+ *
+ * Programs an ISA DMA transfer for the given buffer.
+ */
+void snd_dma_program(unsigned long dma,
+		     unsigned long addr, unsigned int size,
+                     unsigned short mode)
+{
+	unsigned long flags;
+
+	flags = claim_dma_lock();
+	disable_dma(dma);
+	clear_dma_ff(dma);
+	set_dma_mode(dma, mode);
+	set_dma_addr(dma, addr);
+	set_dma_count(dma, size);
+	if (!(mode & DMA_MODE_NO_ENABLE))
+		enable_dma(dma);
+	release_dma_lock(flags);
+}
+EXPORT_SYMBOL(snd_dma_program);
+
+/**
+ * snd_dma_disable - stop the ISA DMA transfer
+ * @dma: the dma number
+ *
+ * Stops the ISA DMA transfer.
+ */
+void snd_dma_disable(unsigned long dma)
+{
+	unsigned long flags;
+
+	flags = claim_dma_lock();
+	clear_dma_ff(dma);
+	disable_dma(dma);
+	release_dma_lock(flags);
+}
+EXPORT_SYMBOL(snd_dma_disable);
+
+/**
+ * snd_dma_pointer - return the current pointer to DMA transfer buffer in bytes
+ * @dma: the dma number
+ * @size: the dma transfer size
+ *
+ * Return: The current pointer in DMA transfer buffer in bytes.
+ */
+unsigned int snd_dma_pointer(unsigned long dma, unsigned int size)
+{
+	unsigned long flags;
+	unsigned int result, result1;
+
+	flags = claim_dma_lock();
+	clear_dma_ff(dma);
+	if (!isa_dma_bridge_buggy)
+		disable_dma(dma);
+	result = get_dma_residue(dma);
+	/*
+	 * HACK - read the counter again and choose higher value in order to
+	 * avoid reading during counter lower byte roll over if the
+	 * isa_dma_bridge_buggy is set.
+	 */
+	result1 = get_dma_residue(dma);
+	if (!isa_dma_bridge_buggy)
+		enable_dma(dma);
+	release_dma_lock(flags);
+	if (unlikely(result < result1))
+		result = result1;
+#ifdef CONFIG_SND_DEBUG
+	if (result > size)
+		pr_err("ALSA: pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size);
+#endif
+	if (result >= size || result == 0)
+		return 0;
+	else
+		return size - result;
+}
+EXPORT_SYMBOL(snd_dma_pointer);
+
+struct snd_dma_data {
+	int dma;
+};
+
+static void __snd_release_dma(struct device *dev, void *data)
+{
+	struct snd_dma_data *p = data;
+
+	snd_dma_disable(p->dma);
+	free_dma(p->dma);
+}
+
+/**
+ * snd_devm_request_dma - the managed version of request_dma()
+ * @dev: the device pointer
+ * @dma: the dma number
+ * @name: the name string of the requester
+ *
+ * The requested DMA will be automatically released at unbinding via devres.
+ *
+ * Return: zero on success, or a negative error code
+ */
+int snd_devm_request_dma(struct device *dev, int dma, const char *name)
+{
+	struct snd_dma_data *p;
+
+	if (request_dma(dma, name))
+		return -EBUSY;
+	p = devres_alloc(__snd_release_dma, sizeof(*p), GFP_KERNEL);
+	if (!p) {
+		free_dma(dma);
+		return -ENOMEM;
+	}
+	p->dma = dma;
+	devres_add(dev, p);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_devm_request_dma);
diff --git a/sound/core/jack.c b/sound/core/jack.c
new file mode 100644
index 0000000000..e0f034e727
--- /dev/null
+++ b/sound/core/jack.c
@@ -0,0 +1,697 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Jack abstraction layer
+ *
+ *  Copyright 2008 Wolfson Microelectronics
+ */
+
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/debugfs.h>
+#include <sound/jack.h>
+#include <sound/core.h>
+#include <sound/control.h>
+
+struct snd_jack_kctl {
+	struct snd_kcontrol *kctl;
+	struct list_head list;  /* list of controls belong to the same jack */
+	unsigned int mask_bits; /* only masked status bits are reported via kctl */
+	struct snd_jack *jack;  /* pointer to struct snd_jack */
+	bool sw_inject_enable;  /* allow to inject plug event via debugfs */
+#ifdef CONFIG_SND_JACK_INJECTION_DEBUG
+	struct dentry *jack_debugfs_root; /* jack_kctl debugfs root */
+#endif
+};
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+static const int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
+	SW_HEADPHONE_INSERT,
+	SW_MICROPHONE_INSERT,
+	SW_LINEOUT_INSERT,
+	SW_JACK_PHYSICAL_INSERT,
+	SW_VIDEOOUT_INSERT,
+	SW_LINEIN_INSERT,
+};
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+
+static int snd_jack_dev_disconnect(struct snd_device *device)
+{
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	struct snd_jack *jack = device->device_data;
+
+	mutex_lock(&jack->input_dev_lock);
+	if (!jack->input_dev) {
+		mutex_unlock(&jack->input_dev_lock);
+		return 0;
+	}
+
+	/* If the input device is registered with the input subsystem
+	 * then we need to use a different deallocator. */
+	if (jack->registered)
+		input_unregister_device(jack->input_dev);
+	else
+		input_free_device(jack->input_dev);
+	jack->input_dev = NULL;
+	mutex_unlock(&jack->input_dev_lock);
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+	return 0;
+}
+
+static int snd_jack_dev_free(struct snd_device *device)
+{
+	struct snd_jack *jack = device->device_data;
+	struct snd_card *card = device->card;
+	struct snd_jack_kctl *jack_kctl, *tmp_jack_kctl;
+
+	list_for_each_entry_safe(jack_kctl, tmp_jack_kctl, &jack->kctl_list, list) {
+		list_del_init(&jack_kctl->list);
+		snd_ctl_remove(card, jack_kctl->kctl);
+	}
+
+	if (jack->private_free)
+		jack->private_free(jack);
+
+	snd_jack_dev_disconnect(device);
+
+	kfree(jack->id);
+	kfree(jack);
+
+	return 0;
+}
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+static int snd_jack_dev_register(struct snd_device *device)
+{
+	struct snd_jack *jack = device->device_data;
+	struct snd_card *card = device->card;
+	int err, i;
+
+	snprintf(jack->name, sizeof(jack->name), "%s %s",
+		 card->shortname, jack->id);
+
+	mutex_lock(&jack->input_dev_lock);
+	if (!jack->input_dev) {
+		mutex_unlock(&jack->input_dev_lock);
+		return 0;
+	}
+
+	jack->input_dev->name = jack->name;
+
+	/* Default to the sound card device. */
+	if (!jack->input_dev->dev.parent)
+		jack->input_dev->dev.parent = snd_card_get_device_link(card);
+
+	/* Add capabilities for any keys that are enabled */
+	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
+		int testbit = SND_JACK_BTN_0 >> i;
+
+		if (!(jack->type & testbit))
+			continue;
+
+		if (!jack->key[i])
+			jack->key[i] = BTN_0 + i;
+
+		input_set_capability(jack->input_dev, EV_KEY, jack->key[i]);
+	}
+
+	err = input_register_device(jack->input_dev);
+	if (err == 0)
+		jack->registered = 1;
+
+	mutex_unlock(&jack->input_dev_lock);
+	return err;
+}
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+
+#ifdef CONFIG_SND_JACK_INJECTION_DEBUG
+static void snd_jack_inject_report(struct snd_jack_kctl *jack_kctl, int status)
+{
+	struct snd_jack *jack;
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	int i;
+#endif
+	if (!jack_kctl)
+		return;
+
+	jack = jack_kctl->jack;
+
+	if (jack_kctl->sw_inject_enable)
+		snd_kctl_jack_report(jack->card, jack_kctl->kctl,
+				     status & jack_kctl->mask_bits);
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	if (!jack->input_dev)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
+		int testbit = ((SND_JACK_BTN_0 >> i) & jack_kctl->mask_bits);
+
+		if (jack->type & testbit)
+			input_report_key(jack->input_dev, jack->key[i],
+					 status & testbit);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
+		int testbit = ((1 << i) & jack_kctl->mask_bits);
+
+		if (jack->type & testbit)
+			input_report_switch(jack->input_dev,
+					    jack_switch_types[i],
+					    status & testbit);
+	}
+
+	input_sync(jack->input_dev);
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+}
+
+static ssize_t sw_inject_enable_read(struct file *file,
+				     char __user *to, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	int len, ret;
+	char buf[128];
+
+	len = scnprintf(buf, sizeof(buf), "%s: %s\t\t%s: %i\n", "Jack", jack_kctl->kctl->id.name,
+			"Inject Enabled", jack_kctl->sw_inject_enable);
+	ret = simple_read_from_buffer(to, count, ppos, buf, len);
+
+	return ret;
+}
+
+static ssize_t sw_inject_enable_write(struct file *file,
+				      const char __user *from, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	int ret, err;
+	unsigned long enable;
+	char buf[8] = { 0 };
+
+	ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, from, count);
+	err = kstrtoul(buf, 0, &enable);
+	if (err)
+		return err;
+
+	if (jack_kctl->sw_inject_enable == (!!enable))
+		return ret;
+
+	jack_kctl->sw_inject_enable = !!enable;
+
+	if (!jack_kctl->sw_inject_enable)
+		snd_jack_report(jack_kctl->jack, jack_kctl->jack->hw_status_cache);
+
+	return ret;
+}
+
+static ssize_t jackin_inject_write(struct file *file,
+				   const char __user *from, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	int ret, err;
+	unsigned long enable;
+	char buf[8] = { 0 };
+
+	if (!jack_kctl->sw_inject_enable)
+		return -EINVAL;
+
+	ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, from, count);
+	err = kstrtoul(buf, 0, &enable);
+	if (err)
+		return err;
+
+	snd_jack_inject_report(jack_kctl, !!enable ? jack_kctl->mask_bits : 0);
+
+	return ret;
+}
+
+static ssize_t jack_kctl_id_read(struct file *file,
+				 char __user *to, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	char buf[64];
+	int len, ret;
+
+	len = scnprintf(buf, sizeof(buf), "%s\n", jack_kctl->kctl->id.name);
+	ret = simple_read_from_buffer(to, count, ppos, buf, len);
+
+	return ret;
+}
+
+/* the bit definition is aligned with snd_jack_types in jack.h */
+static const char * const jack_events_name[] = {
+	"HEADPHONE(0x0001)", "MICROPHONE(0x0002)", "LINEOUT(0x0004)",
+	"MECHANICAL(0x0008)", "VIDEOOUT(0x0010)", "LINEIN(0x0020)",
+	"", "", "", "BTN_5(0x0200)", "BTN_4(0x0400)", "BTN_3(0x0800)",
+	"BTN_2(0x1000)", "BTN_1(0x2000)", "BTN_0(0x4000)", "",
+};
+
+/* the recommended buffer size is 256 */
+static int parse_mask_bits(unsigned int mask_bits, char *buf, size_t buf_size)
+{
+	int i;
+
+	scnprintf(buf, buf_size, "0x%04x", mask_bits);
+
+	for (i = 0; i < ARRAY_SIZE(jack_events_name); i++)
+		if (mask_bits & (1 << i)) {
+			strlcat(buf, " ", buf_size);
+			strlcat(buf, jack_events_name[i], buf_size);
+		}
+	strlcat(buf, "\n", buf_size);
+
+	return strlen(buf);
+}
+
+static ssize_t jack_kctl_mask_bits_read(struct file *file,
+					char __user *to, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	char buf[256];
+	int len, ret;
+
+	len = parse_mask_bits(jack_kctl->mask_bits, buf, sizeof(buf));
+	ret = simple_read_from_buffer(to, count, ppos, buf, len);
+
+	return ret;
+}
+
+static ssize_t jack_kctl_status_read(struct file *file,
+				     char __user *to, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	char buf[16];
+	int len, ret;
+
+	len = scnprintf(buf, sizeof(buf), "%s\n", jack_kctl->kctl->private_value ?
+			"Plugged" : "Unplugged");
+	ret = simple_read_from_buffer(to, count, ppos, buf, len);
+
+	return ret;
+}
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+static ssize_t jack_type_read(struct file *file,
+			      char __user *to, size_t count, loff_t *ppos)
+{
+	struct snd_jack_kctl *jack_kctl = file->private_data;
+	char buf[256];
+	int len, ret;
+
+	len = parse_mask_bits(jack_kctl->jack->type, buf, sizeof(buf));
+	ret = simple_read_from_buffer(to, count, ppos, buf, len);
+
+	return ret;
+}
+
+static const struct file_operations jack_type_fops = {
+	.open = simple_open,
+	.read = jack_type_read,
+	.llseek = default_llseek,
+};
+#endif
+
+static const struct file_operations sw_inject_enable_fops = {
+	.open = simple_open,
+	.read = sw_inject_enable_read,
+	.write = sw_inject_enable_write,
+	.llseek = default_llseek,
+};
+
+static const struct file_operations jackin_inject_fops = {
+	.open = simple_open,
+	.write = jackin_inject_write,
+	.llseek = default_llseek,
+};
+
+static const struct file_operations jack_kctl_id_fops = {
+	.open = simple_open,
+	.read = jack_kctl_id_read,
+	.llseek = default_llseek,
+};
+
+static const struct file_operations jack_kctl_mask_bits_fops = {
+	.open = simple_open,
+	.read = jack_kctl_mask_bits_read,
+	.llseek = default_llseek,
+};
+
+static const struct file_operations jack_kctl_status_fops = {
+	.open = simple_open,
+	.read = jack_kctl_status_read,
+	.llseek = default_llseek,
+};
+
+static int snd_jack_debugfs_add_inject_node(struct snd_jack *jack,
+					    struct snd_jack_kctl *jack_kctl)
+{
+	char *tname;
+	int i;
+
+	/* Don't create injection interface for Phantom jacks */
+	if (strstr(jack_kctl->kctl->id.name, "Phantom"))
+		return 0;
+
+	tname = kstrdup(jack_kctl->kctl->id.name, GFP_KERNEL);
+	if (!tname)
+		return -ENOMEM;
+
+	/* replace the chars which are not suitable for folder's name with _ */
+	for (i = 0; tname[i]; i++)
+		if (!isalnum(tname[i]))
+			tname[i] = '_';
+
+	jack_kctl->jack_debugfs_root = debugfs_create_dir(tname, jack->card->debugfs_root);
+	kfree(tname);
+
+	debugfs_create_file("sw_inject_enable", 0644, jack_kctl->jack_debugfs_root, jack_kctl,
+			    &sw_inject_enable_fops);
+
+	debugfs_create_file("jackin_inject", 0200, jack_kctl->jack_debugfs_root, jack_kctl,
+			    &jackin_inject_fops);
+
+	debugfs_create_file("kctl_id", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
+			    &jack_kctl_id_fops);
+
+	debugfs_create_file("mask_bits", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
+			    &jack_kctl_mask_bits_fops);
+
+	debugfs_create_file("status", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
+			    &jack_kctl_status_fops);
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	debugfs_create_file("type", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
+			    &jack_type_fops);
+#endif
+	return 0;
+}
+
+static void snd_jack_debugfs_clear_inject_node(struct snd_jack_kctl *jack_kctl)
+{
+	debugfs_remove(jack_kctl->jack_debugfs_root);
+	jack_kctl->jack_debugfs_root = NULL;
+}
+#else /* CONFIG_SND_JACK_INJECTION_DEBUG */
+static int snd_jack_debugfs_add_inject_node(struct snd_jack *jack,
+					    struct snd_jack_kctl *jack_kctl)
+{
+	return 0;
+}
+
+static void snd_jack_debugfs_clear_inject_node(struct snd_jack_kctl *jack_kctl)
+{
+}
+#endif /* CONFIG_SND_JACK_INJECTION_DEBUG */
+
+static void snd_jack_kctl_private_free(struct snd_kcontrol *kctl)
+{
+	struct snd_jack_kctl *jack_kctl;
+
+	jack_kctl = kctl->private_data;
+	if (jack_kctl) {
+		snd_jack_debugfs_clear_inject_node(jack_kctl);
+		list_del(&jack_kctl->list);
+		kfree(jack_kctl);
+	}
+}
+
+static void snd_jack_kctl_add(struct snd_jack *jack, struct snd_jack_kctl *jack_kctl)
+{
+	jack_kctl->jack = jack;
+	list_add_tail(&jack_kctl->list, &jack->kctl_list);
+	snd_jack_debugfs_add_inject_node(jack, jack_kctl);
+}
+
+static struct snd_jack_kctl * snd_jack_kctl_new(struct snd_card *card, const char *name, unsigned int mask)
+{
+	struct snd_kcontrol *kctl;
+	struct snd_jack_kctl *jack_kctl;
+	int err;
+
+	kctl = snd_kctl_jack_new(name, card);
+	if (!kctl)
+		return NULL;
+
+	err = snd_ctl_add(card, kctl);
+	if (err < 0)
+		return NULL;
+
+	jack_kctl = kzalloc(sizeof(*jack_kctl), GFP_KERNEL);
+
+	if (!jack_kctl)
+		goto error;
+
+	jack_kctl->kctl = kctl;
+	jack_kctl->mask_bits = mask;
+
+	kctl->private_data = jack_kctl;
+	kctl->private_free = snd_jack_kctl_private_free;
+
+	return jack_kctl;
+error:
+	snd_ctl_free_one(kctl);
+	return NULL;
+}
+
+/**
+ * snd_jack_add_new_kctl - Create a new snd_jack_kctl and add it to jack
+ * @jack:  the jack instance which the kctl will attaching to
+ * @name:  the name for the snd_kcontrol object
+ * @mask:  a bitmask of enum snd_jack_type values that can be detected
+ *         by this snd_jack_kctl object.
+ *
+ * Creates a new snd_kcontrol object and adds it to the jack kctl_list.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_jack_add_new_kctl(struct snd_jack *jack, const char * name, int mask)
+{
+	struct snd_jack_kctl *jack_kctl;
+
+	jack_kctl = snd_jack_kctl_new(jack->card, name, mask);
+	if (!jack_kctl)
+		return -ENOMEM;
+
+	snd_jack_kctl_add(jack, jack_kctl);
+	return 0;
+}
+EXPORT_SYMBOL(snd_jack_add_new_kctl);
+
+/**
+ * snd_jack_new - Create a new jack
+ * @card:  the card instance
+ * @id:    an identifying string for this jack
+ * @type:  a bitmask of enum snd_jack_type values that can be detected by
+ *         this jack
+ * @jjack: Used to provide the allocated jack object to the caller.
+ * @initial_kctl: if true, create a kcontrol and add it to the jack list.
+ * @phantom_jack: Don't create a input device for phantom jacks.
+ *
+ * Creates a new jack object.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ * On success @jjack will be initialised.
+ */
+int snd_jack_new(struct snd_card *card, const char *id, int type,
+		 struct snd_jack **jjack, bool initial_kctl, bool phantom_jack)
+{
+	struct snd_jack *jack;
+	struct snd_jack_kctl *jack_kctl = NULL;
+	int err;
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_jack_dev_free,
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+		.dev_register = snd_jack_dev_register,
+		.dev_disconnect = snd_jack_dev_disconnect,
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+	};
+
+	if (initial_kctl) {
+		jack_kctl = snd_jack_kctl_new(card, id, type);
+		if (!jack_kctl)
+			return -ENOMEM;
+	}
+
+	jack = kzalloc(sizeof(struct snd_jack), GFP_KERNEL);
+	if (jack == NULL)
+		return -ENOMEM;
+
+	jack->id = kstrdup(id, GFP_KERNEL);
+	if (jack->id == NULL) {
+		kfree(jack);
+		return -ENOMEM;
+	}
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	mutex_init(&jack->input_dev_lock);
+
+	/* don't create input device for phantom jack */
+	if (!phantom_jack) {
+		int i;
+
+		jack->input_dev = input_allocate_device();
+		if (jack->input_dev == NULL) {
+			err = -ENOMEM;
+			goto fail_input;
+		}
+
+		jack->input_dev->phys = "ALSA";
+
+		jack->type = type;
+
+		for (i = 0; i < SND_JACK_SWITCH_TYPES; i++)
+			if (type & (1 << i))
+				input_set_capability(jack->input_dev, EV_SW,
+						     jack_switch_types[i]);
+
+	}
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+
+	err = snd_device_new(card, SNDRV_DEV_JACK, jack, &ops);
+	if (err < 0)
+		goto fail_input;
+
+	jack->card = card;
+	INIT_LIST_HEAD(&jack->kctl_list);
+
+	if (initial_kctl)
+		snd_jack_kctl_add(jack, jack_kctl);
+
+	*jjack = jack;
+
+	return 0;
+
+fail_input:
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	input_free_device(jack->input_dev);
+#endif
+	kfree(jack->id);
+	kfree(jack);
+	return err;
+}
+EXPORT_SYMBOL(snd_jack_new);
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+/**
+ * snd_jack_set_parent - Set the parent device for a jack
+ *
+ * @jack:   The jack to configure
+ * @parent: The device to set as parent for the jack.
+ *
+ * Set the parent for the jack devices in the device tree.  This
+ * function is only valid prior to registration of the jack.  If no
+ * parent is configured then the parent device will be the sound card.
+ */
+void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
+{
+	WARN_ON(jack->registered);
+	mutex_lock(&jack->input_dev_lock);
+	if (!jack->input_dev) {
+		mutex_unlock(&jack->input_dev_lock);
+		return;
+	}
+
+	jack->input_dev->dev.parent = parent;
+	mutex_unlock(&jack->input_dev_lock);
+}
+EXPORT_SYMBOL(snd_jack_set_parent);
+
+/**
+ * snd_jack_set_key - Set a key mapping on a jack
+ *
+ * @jack:    The jack to configure
+ * @type:    Jack report type for this key
+ * @keytype: Input layer key type to be reported
+ *
+ * Map a SND_JACK_BTN_* button type to an input layer key, allowing
+ * reporting of keys on accessories via the jack abstraction.  If no
+ * mapping is provided but keys are enabled in the jack type then
+ * BTN_n numeric buttons will be reported.
+ *
+ * If jacks are not reporting via the input API this call will have no
+ * effect.
+ *
+ * Note that this is intended to be use by simple devices with small
+ * numbers of keys that can be reported.  It is also possible to
+ * access the input device directly - devices with complex input
+ * capabilities on accessories should consider doing this rather than
+ * using this abstraction.
+ *
+ * This function may only be called prior to registration of the jack.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
+		     int keytype)
+{
+	int key = fls(SND_JACK_BTN_0) - fls(type);
+
+	WARN_ON(jack->registered);
+
+	if (!keytype || key >= ARRAY_SIZE(jack->key))
+		return -EINVAL;
+
+	jack->type |= type;
+	jack->key[key] = keytype;
+	return 0;
+}
+EXPORT_SYMBOL(snd_jack_set_key);
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+
+/**
+ * snd_jack_report - Report the current status of a jack
+ * Note: This function uses mutexes and should be called from a
+ * context which can sleep (such as a workqueue).
+ *
+ * @jack:   The jack to report status for
+ * @status: The current status of the jack
+ */
+void snd_jack_report(struct snd_jack *jack, int status)
+{
+	struct snd_jack_kctl *jack_kctl;
+	unsigned int mask_bits = 0;
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	struct input_dev *idev;
+	int i;
+#endif
+
+	if (!jack)
+		return;
+
+	jack->hw_status_cache = status;
+
+	list_for_each_entry(jack_kctl, &jack->kctl_list, list)
+		if (jack_kctl->sw_inject_enable)
+			mask_bits |= jack_kctl->mask_bits;
+		else
+			snd_kctl_jack_report(jack->card, jack_kctl->kctl,
+					     status & jack_kctl->mask_bits);
+
+#ifdef CONFIG_SND_JACK_INPUT_DEV
+	idev = input_get_device(jack->input_dev);
+	if (!idev)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
+		int testbit = ((SND_JACK_BTN_0 >> i) & ~mask_bits);
+
+		if (jack->type & testbit)
+			input_report_key(idev, jack->key[i],
+					 status & testbit);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
+		int testbit = ((1 << i) & ~mask_bits);
+
+		if (jack->type & testbit)
+			input_report_switch(idev,
+					    jack_switch_types[i],
+					    status & testbit);
+	}
+
+	input_sync(idev);
+	input_put_device(idev);
+#endif /* CONFIG_SND_JACK_INPUT_DEV */
+}
+EXPORT_SYMBOL(snd_jack_report);
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
new file mode 100644
index 0000000000..f901504b5a
--- /dev/null
+++ b/sound/core/memalloc.c
@@ -0,0 +1,950 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *                   Takashi Iwai <tiwai@suse.de>
+ * 
+ *  Generic memory allocators
+ */
+
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
+#include <linux/genalloc.h>
+#include <linux/highmem.h>
+#include <linux/vmalloc.h>
+#ifdef CONFIG_X86
+#include <asm/set_memory.h>
+#endif
+#include <sound/memalloc.h>
+#include "memalloc_local.h"
+
+#define DEFAULT_GFP \
+	(GFP_KERNEL | \
+	 __GFP_RETRY_MAYFAIL | /* don't trigger OOM-killer */ \
+	 __GFP_NOWARN)   /* no stack trace print - this call is non-critical */
+
+static const struct snd_malloc_ops *snd_dma_get_ops(struct snd_dma_buffer *dmab);
+
+#ifdef CONFIG_SND_DMA_SGBUF
+static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size);
+#endif
+
+static void *__snd_dma_alloc_pages(struct snd_dma_buffer *dmab, size_t size)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (WARN_ON_ONCE(!ops || !ops->alloc))
+		return NULL;
+	return ops->alloc(dmab, size);
+}
+
+/**
+ * snd_dma_alloc_dir_pages - allocate the buffer area according to the given
+ *	type and direction
+ * @type: the DMA buffer type
+ * @device: the device pointer
+ * @dir: DMA direction
+ * @size: the buffer size to allocate
+ * @dmab: buffer allocation record to store the allocated data
+ *
+ * Calls the memory-allocator function for the corresponding
+ * buffer type.
+ *
+ * Return: Zero if the buffer with the given size is allocated successfully,
+ * otherwise a negative value on error.
+ */
+int snd_dma_alloc_dir_pages(int type, struct device *device,
+			    enum dma_data_direction dir, size_t size,
+			    struct snd_dma_buffer *dmab)
+{
+	if (WARN_ON(!size))
+		return -ENXIO;
+	if (WARN_ON(!dmab))
+		return -ENXIO;
+
+	size = PAGE_ALIGN(size);
+	dmab->dev.type = type;
+	dmab->dev.dev = device;
+	dmab->dev.dir = dir;
+	dmab->bytes = 0;
+	dmab->addr = 0;
+	dmab->private_data = NULL;
+	dmab->area = __snd_dma_alloc_pages(dmab, size);
+	if (!dmab->area)
+		return -ENOMEM;
+	dmab->bytes = size;
+	return 0;
+}
+EXPORT_SYMBOL(snd_dma_alloc_dir_pages);
+
+/**
+ * snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
+ * @type: the DMA buffer type
+ * @device: the device pointer
+ * @size: the buffer size to allocate
+ * @dmab: buffer allocation record to store the allocated data
+ *
+ * Calls the memory-allocator function for the corresponding
+ * buffer type.  When no space is left, this function reduces the size and
+ * tries to allocate again.  The size actually allocated is stored in
+ * res_size argument.
+ *
+ * Return: Zero if the buffer with the given size is allocated successfully,
+ * otherwise a negative value on error.
+ */
+int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
+				 struct snd_dma_buffer *dmab)
+{
+	int err;
+
+	while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
+		if (err != -ENOMEM)
+			return err;
+		if (size <= PAGE_SIZE)
+			return -ENOMEM;
+		size >>= 1;
+		size = PAGE_SIZE << get_order(size);
+	}
+	if (! dmab->area)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
+
+/**
+ * snd_dma_free_pages - release the allocated buffer
+ * @dmab: the buffer allocation record to release
+ *
+ * Releases the allocated buffer via snd_dma_alloc_pages().
+ */
+void snd_dma_free_pages(struct snd_dma_buffer *dmab)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->free)
+		ops->free(dmab);
+}
+EXPORT_SYMBOL(snd_dma_free_pages);
+
+/* called by devres */
+static void __snd_release_pages(struct device *dev, void *res)
+{
+	snd_dma_free_pages(res);
+}
+
+/**
+ * snd_devm_alloc_dir_pages - allocate the buffer and manage with devres
+ * @dev: the device pointer
+ * @type: the DMA buffer type
+ * @dir: DMA direction
+ * @size: the buffer size to allocate
+ *
+ * Allocate buffer pages depending on the given type and manage using devres.
+ * The pages will be released automatically at the device removal.
+ *
+ * Unlike snd_dma_alloc_pages(), this function requires the real device pointer,
+ * hence it can't work with SNDRV_DMA_TYPE_CONTINUOUS or
+ * SNDRV_DMA_TYPE_VMALLOC type.
+ *
+ * Return: the snd_dma_buffer object at success, or NULL if failed
+ */
+struct snd_dma_buffer *
+snd_devm_alloc_dir_pages(struct device *dev, int type,
+			 enum dma_data_direction dir, size_t size)
+{
+	struct snd_dma_buffer *dmab;
+	int err;
+
+	if (WARN_ON(type == SNDRV_DMA_TYPE_CONTINUOUS ||
+		    type == SNDRV_DMA_TYPE_VMALLOC))
+		return NULL;
+
+	dmab = devres_alloc(__snd_release_pages, sizeof(*dmab), GFP_KERNEL);
+	if (!dmab)
+		return NULL;
+
+	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
+	if (err < 0) {
+		devres_free(dmab);
+		return NULL;
+	}
+
+	devres_add(dev, dmab);
+	return dmab;
+}
+EXPORT_SYMBOL_GPL(snd_devm_alloc_dir_pages);
+
+/**
+ * snd_dma_buffer_mmap - perform mmap of the given DMA buffer
+ * @dmab: buffer allocation information
+ * @area: VM area information
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_dma_buffer_mmap(struct snd_dma_buffer *dmab,
+			struct vm_area_struct *area)
+{
+	const struct snd_malloc_ops *ops;
+
+	if (!dmab)
+		return -ENOENT;
+	ops = snd_dma_get_ops(dmab);
+	if (ops && ops->mmap)
+		return ops->mmap(dmab, area);
+	else
+		return -ENOENT;
+}
+EXPORT_SYMBOL(snd_dma_buffer_mmap);
+
+#ifdef CONFIG_HAS_DMA
+/**
+ * snd_dma_buffer_sync - sync DMA buffer between CPU and device
+ * @dmab: buffer allocation information
+ * @mode: sync mode
+ */
+void snd_dma_buffer_sync(struct snd_dma_buffer *dmab,
+			 enum snd_dma_sync_mode mode)
+{
+	const struct snd_malloc_ops *ops;
+
+	if (!dmab || !dmab->dev.need_sync)
+		return;
+	ops = snd_dma_get_ops(dmab);
+	if (ops && ops->sync)
+		ops->sync(dmab, mode);
+}
+EXPORT_SYMBOL_GPL(snd_dma_buffer_sync);
+#endif /* CONFIG_HAS_DMA */
+
+/**
+ * snd_sgbuf_get_addr - return the physical address at the corresponding offset
+ * @dmab: buffer allocation information
+ * @offset: offset in the ring buffer
+ *
+ * Return: the physical address
+ */
+dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->get_addr)
+		return ops->get_addr(dmab, offset);
+	else
+		return dmab->addr + offset;
+}
+EXPORT_SYMBOL(snd_sgbuf_get_addr);
+
+/**
+ * snd_sgbuf_get_page - return the physical page at the corresponding offset
+ * @dmab: buffer allocation information
+ * @offset: offset in the ring buffer
+ *
+ * Return: the page pointer
+ */
+struct page *snd_sgbuf_get_page(struct snd_dma_buffer *dmab, size_t offset)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->get_page)
+		return ops->get_page(dmab, offset);
+	else
+		return virt_to_page(dmab->area + offset);
+}
+EXPORT_SYMBOL(snd_sgbuf_get_page);
+
+/**
+ * snd_sgbuf_get_chunk_size - compute the max chunk size with continuous pages
+ *	on sg-buffer
+ * @dmab: buffer allocation information
+ * @ofs: offset in the ring buffer
+ * @size: the requested size
+ *
+ * Return: the chunk size
+ */
+unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
+				      unsigned int ofs, unsigned int size)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->get_chunk_size)
+		return ops->get_chunk_size(dmab, ofs, size);
+	else
+		return size;
+}
+EXPORT_SYMBOL(snd_sgbuf_get_chunk_size);
+
+/*
+ * Continuous pages allocator
+ */
+static void *do_alloc_pages(struct device *dev, size_t size, dma_addr_t *addr,
+			    bool wc)
+{
+	void *p;
+	gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
+
+ again:
+	p = alloc_pages_exact(size, gfp);
+	if (!p)
+		return NULL;
+	*addr = page_to_phys(virt_to_page(p));
+	if (!dev)
+		return p;
+	if ((*addr + size - 1) & ~dev->coherent_dma_mask) {
+		if (IS_ENABLED(CONFIG_ZONE_DMA32) && !(gfp & GFP_DMA32)) {
+			gfp |= GFP_DMA32;
+			goto again;
+		}
+		if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) {
+			gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
+			goto again;
+		}
+	}
+#ifdef CONFIG_X86
+	if (wc)
+		set_memory_wc((unsigned long)(p), size >> PAGE_SHIFT);
+#endif
+	return p;
+}
+
+static void do_free_pages(void *p, size_t size, bool wc)
+{
+#ifdef CONFIG_X86
+	if (wc)
+		set_memory_wb((unsigned long)(p), size >> PAGE_SHIFT);
+#endif
+	free_pages_exact(p, size);
+}
+
+
+static void *snd_dma_continuous_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return do_alloc_pages(dmab->dev.dev, size, &dmab->addr, false);
+}
+
+static void snd_dma_continuous_free(struct snd_dma_buffer *dmab)
+{
+	do_free_pages(dmab->area, dmab->bytes, false);
+}
+
+static int snd_dma_continuous_mmap(struct snd_dma_buffer *dmab,
+				   struct vm_area_struct *area)
+{
+	return remap_pfn_range(area, area->vm_start,
+			       dmab->addr >> PAGE_SHIFT,
+			       area->vm_end - area->vm_start,
+			       area->vm_page_prot);
+}
+
+static const struct snd_malloc_ops snd_dma_continuous_ops = {
+	.alloc = snd_dma_continuous_alloc,
+	.free = snd_dma_continuous_free,
+	.mmap = snd_dma_continuous_mmap,
+};
+
+/*
+ * VMALLOC allocator
+ */
+static void *snd_dma_vmalloc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return vmalloc(size);
+}
+
+static void snd_dma_vmalloc_free(struct snd_dma_buffer *dmab)
+{
+	vfree(dmab->area);
+}
+
+static int snd_dma_vmalloc_mmap(struct snd_dma_buffer *dmab,
+				struct vm_area_struct *area)
+{
+	return remap_vmalloc_range(area, dmab->area, 0);
+}
+
+#define get_vmalloc_page_addr(dmab, offset) \
+	page_to_phys(vmalloc_to_page((dmab)->area + (offset)))
+
+static dma_addr_t snd_dma_vmalloc_get_addr(struct snd_dma_buffer *dmab,
+					   size_t offset)
+{
+	return get_vmalloc_page_addr(dmab, offset) + offset % PAGE_SIZE;
+}
+
+static struct page *snd_dma_vmalloc_get_page(struct snd_dma_buffer *dmab,
+					     size_t offset)
+{
+	return vmalloc_to_page(dmab->area + offset);
+}
+
+static unsigned int
+snd_dma_vmalloc_get_chunk_size(struct snd_dma_buffer *dmab,
+			       unsigned int ofs, unsigned int size)
+{
+	unsigned int start, end;
+	unsigned long addr;
+
+	start = ALIGN_DOWN(ofs, PAGE_SIZE);
+	end = ofs + size - 1; /* the last byte address */
+	/* check page continuity */
+	addr = get_vmalloc_page_addr(dmab, start);
+	for (;;) {
+		start += PAGE_SIZE;
+		if (start > end)
+			break;
+		addr += PAGE_SIZE;
+		if (get_vmalloc_page_addr(dmab, start) != addr)
+			return start - ofs;
+	}
+	/* ok, all on continuous pages */
+	return size;
+}
+
+static const struct snd_malloc_ops snd_dma_vmalloc_ops = {
+	.alloc = snd_dma_vmalloc_alloc,
+	.free = snd_dma_vmalloc_free,
+	.mmap = snd_dma_vmalloc_mmap,
+	.get_addr = snd_dma_vmalloc_get_addr,
+	.get_page = snd_dma_vmalloc_get_page,
+	.get_chunk_size = snd_dma_vmalloc_get_chunk_size,
+};
+
+#ifdef CONFIG_HAS_DMA
+/*
+ * IRAM allocator
+ */
+#ifdef CONFIG_GENERIC_ALLOCATOR
+static void *snd_dma_iram_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	struct device *dev = dmab->dev.dev;
+	struct gen_pool *pool;
+	void *p;
+
+	if (dev->of_node) {
+		pool = of_gen_pool_get(dev->of_node, "iram", 0);
+		/* Assign the pool into private_data field */
+		dmab->private_data = pool;
+
+		p = gen_pool_dma_alloc_align(pool, size, &dmab->addr, PAGE_SIZE);
+		if (p)
+			return p;
+	}
+
+	/* Internal memory might have limited size and no enough space,
+	 * so if we fail to malloc, try to fetch memory traditionally.
+	 */
+	dmab->dev.type = SNDRV_DMA_TYPE_DEV;
+	return __snd_dma_alloc_pages(dmab, size);
+}
+
+static void snd_dma_iram_free(struct snd_dma_buffer *dmab)
+{
+	struct gen_pool *pool = dmab->private_data;
+
+	if (pool && dmab->area)
+		gen_pool_free(pool, (unsigned long)dmab->area, dmab->bytes);
+}
+
+static int snd_dma_iram_mmap(struct snd_dma_buffer *dmab,
+			     struct vm_area_struct *area)
+{
+	area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return remap_pfn_range(area, area->vm_start,
+			       dmab->addr >> PAGE_SHIFT,
+			       area->vm_end - area->vm_start,
+			       area->vm_page_prot);
+}
+
+static const struct snd_malloc_ops snd_dma_iram_ops = {
+	.alloc = snd_dma_iram_alloc,
+	.free = snd_dma_iram_free,
+	.mmap = snd_dma_iram_mmap,
+};
+#endif /* CONFIG_GENERIC_ALLOCATOR */
+
+/*
+ * Coherent device pages allocator
+ */
+static void *snd_dma_dev_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return dma_alloc_coherent(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
+}
+
+static void snd_dma_dev_free(struct snd_dma_buffer *dmab)
+{
+	dma_free_coherent(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
+}
+
+static int snd_dma_dev_mmap(struct snd_dma_buffer *dmab,
+			    struct vm_area_struct *area)
+{
+	return dma_mmap_coherent(dmab->dev.dev, area,
+				 dmab->area, dmab->addr, dmab->bytes);
+}
+
+static const struct snd_malloc_ops snd_dma_dev_ops = {
+	.alloc = snd_dma_dev_alloc,
+	.free = snd_dma_dev_free,
+	.mmap = snd_dma_dev_mmap,
+};
+
+/*
+ * Write-combined pages
+ */
+/* x86-specific allocations */
+#ifdef CONFIG_SND_DMA_SGBUF
+static void *snd_dma_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return do_alloc_pages(dmab->dev.dev, size, &dmab->addr, true);
+}
+
+static void snd_dma_wc_free(struct snd_dma_buffer *dmab)
+{
+	do_free_pages(dmab->area, dmab->bytes, true);
+}
+
+static int snd_dma_wc_mmap(struct snd_dma_buffer *dmab,
+			   struct vm_area_struct *area)
+{
+	area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return snd_dma_continuous_mmap(dmab, area);
+}
+#else
+static void *snd_dma_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return dma_alloc_wc(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
+}
+
+static void snd_dma_wc_free(struct snd_dma_buffer *dmab)
+{
+	dma_free_wc(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
+}
+
+static int snd_dma_wc_mmap(struct snd_dma_buffer *dmab,
+			   struct vm_area_struct *area)
+{
+	return dma_mmap_wc(dmab->dev.dev, area,
+			   dmab->area, dmab->addr, dmab->bytes);
+}
+#endif /* CONFIG_SND_DMA_SGBUF */
+
+static const struct snd_malloc_ops snd_dma_wc_ops = {
+	.alloc = snd_dma_wc_alloc,
+	.free = snd_dma_wc_free,
+	.mmap = snd_dma_wc_mmap,
+};
+
+/*
+ * Non-contiguous pages allocator
+ */
+static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	struct sg_table *sgt;
+	void *p;
+
+#ifdef CONFIG_SND_DMA_SGBUF
+	if (cpu_feature_enabled(X86_FEATURE_XENPV))
+		return snd_dma_sg_fallback_alloc(dmab, size);
+#endif
+	sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir,
+				      DEFAULT_GFP, 0);
+#ifdef CONFIG_SND_DMA_SGBUF
+	if (!sgt && !get_dma_ops(dmab->dev.dev))
+		return snd_dma_sg_fallback_alloc(dmab, size);
+#endif
+	if (!sgt)
+		return NULL;
+
+	dmab->dev.need_sync = dma_need_sync(dmab->dev.dev,
+					    sg_dma_address(sgt->sgl));
+	p = dma_vmap_noncontiguous(dmab->dev.dev, size, sgt);
+	if (p) {
+		dmab->private_data = sgt;
+		/* store the first page address for convenience */
+		dmab->addr = snd_sgbuf_get_addr(dmab, 0);
+	} else {
+		dma_free_noncontiguous(dmab->dev.dev, size, sgt, dmab->dev.dir);
+	}
+	return p;
+}
+
+static void snd_dma_noncontig_free(struct snd_dma_buffer *dmab)
+{
+	dma_vunmap_noncontiguous(dmab->dev.dev, dmab->area);
+	dma_free_noncontiguous(dmab->dev.dev, dmab->bytes, dmab->private_data,
+			       dmab->dev.dir);
+}
+
+static int snd_dma_noncontig_mmap(struct snd_dma_buffer *dmab,
+				  struct vm_area_struct *area)
+{
+	return dma_mmap_noncontiguous(dmab->dev.dev, area,
+				      dmab->bytes, dmab->private_data);
+}
+
+static void snd_dma_noncontig_sync(struct snd_dma_buffer *dmab,
+				   enum snd_dma_sync_mode mode)
+{
+	if (mode == SNDRV_DMA_SYNC_CPU) {
+		if (dmab->dev.dir == DMA_TO_DEVICE)
+			return;
+		invalidate_kernel_vmap_range(dmab->area, dmab->bytes);
+		dma_sync_sgtable_for_cpu(dmab->dev.dev, dmab->private_data,
+					 dmab->dev.dir);
+	} else {
+		if (dmab->dev.dir == DMA_FROM_DEVICE)
+			return;
+		flush_kernel_vmap_range(dmab->area, dmab->bytes);
+		dma_sync_sgtable_for_device(dmab->dev.dev, dmab->private_data,
+					    dmab->dev.dir);
+	}
+}
+
+static inline void snd_dma_noncontig_iter_set(struct snd_dma_buffer *dmab,
+					      struct sg_page_iter *piter,
+					      size_t offset)
+{
+	struct sg_table *sgt = dmab->private_data;
+
+	__sg_page_iter_start(piter, sgt->sgl, sgt->orig_nents,
+			     offset >> PAGE_SHIFT);
+}
+
+static dma_addr_t snd_dma_noncontig_get_addr(struct snd_dma_buffer *dmab,
+					     size_t offset)
+{
+	struct sg_dma_page_iter iter;
+
+	snd_dma_noncontig_iter_set(dmab, &iter.base, offset);
+	__sg_page_iter_dma_next(&iter);
+	return sg_page_iter_dma_address(&iter) + offset % PAGE_SIZE;
+}
+
+static struct page *snd_dma_noncontig_get_page(struct snd_dma_buffer *dmab,
+					       size_t offset)
+{
+	struct sg_page_iter iter;
+
+	snd_dma_noncontig_iter_set(dmab, &iter, offset);
+	__sg_page_iter_next(&iter);
+	return sg_page_iter_page(&iter);
+}
+
+static unsigned int
+snd_dma_noncontig_get_chunk_size(struct snd_dma_buffer *dmab,
+				 unsigned int ofs, unsigned int size)
+{
+	struct sg_dma_page_iter iter;
+	unsigned int start, end;
+	unsigned long addr;
+
+	start = ALIGN_DOWN(ofs, PAGE_SIZE);
+	end = ofs + size - 1; /* the last byte address */
+	snd_dma_noncontig_iter_set(dmab, &iter.base, start);
+	if (!__sg_page_iter_dma_next(&iter))
+		return 0;
+	/* check page continuity */
+	addr = sg_page_iter_dma_address(&iter);
+	for (;;) {
+		start += PAGE_SIZE;
+		if (start > end)
+			break;
+		addr += PAGE_SIZE;
+		if (!__sg_page_iter_dma_next(&iter) ||
+		    sg_page_iter_dma_address(&iter) != addr)
+			return start - ofs;
+	}
+	/* ok, all on continuous pages */
+	return size;
+}
+
+static const struct snd_malloc_ops snd_dma_noncontig_ops = {
+	.alloc = snd_dma_noncontig_alloc,
+	.free = snd_dma_noncontig_free,
+	.mmap = snd_dma_noncontig_mmap,
+	.sync = snd_dma_noncontig_sync,
+	.get_addr = snd_dma_noncontig_get_addr,
+	.get_page = snd_dma_noncontig_get_page,
+	.get_chunk_size = snd_dma_noncontig_get_chunk_size,
+};
+
+/* x86-specific SG-buffer with WC pages */
+#ifdef CONFIG_SND_DMA_SGBUF
+#define sg_wc_address(it) ((unsigned long)page_address(sg_page_iter_page(it)))
+
+static void *snd_dma_sg_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	void *p = snd_dma_noncontig_alloc(dmab, size);
+	struct sg_table *sgt = dmab->private_data;
+	struct sg_page_iter iter;
+
+	if (!p)
+		return NULL;
+	if (dmab->dev.type != SNDRV_DMA_TYPE_DEV_WC_SG)
+		return p;
+	for_each_sgtable_page(sgt, &iter, 0)
+		set_memory_wc(sg_wc_address(&iter), 1);
+	return p;
+}
+
+static void snd_dma_sg_wc_free(struct snd_dma_buffer *dmab)
+{
+	struct sg_table *sgt = dmab->private_data;
+	struct sg_page_iter iter;
+
+	for_each_sgtable_page(sgt, &iter, 0)
+		set_memory_wb(sg_wc_address(&iter), 1);
+	snd_dma_noncontig_free(dmab);
+}
+
+static int snd_dma_sg_wc_mmap(struct snd_dma_buffer *dmab,
+			      struct vm_area_struct *area)
+{
+	area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return dma_mmap_noncontiguous(dmab->dev.dev, area,
+				      dmab->bytes, dmab->private_data);
+}
+
+static const struct snd_malloc_ops snd_dma_sg_wc_ops = {
+	.alloc = snd_dma_sg_wc_alloc,
+	.free = snd_dma_sg_wc_free,
+	.mmap = snd_dma_sg_wc_mmap,
+	.sync = snd_dma_noncontig_sync,
+	.get_addr = snd_dma_noncontig_get_addr,
+	.get_page = snd_dma_noncontig_get_page,
+	.get_chunk_size = snd_dma_noncontig_get_chunk_size,
+};
+
+/* Fallback SG-buffer allocations for x86 */
+struct snd_dma_sg_fallback {
+	bool use_dma_alloc_coherent;
+	size_t count;
+	struct page **pages;
+	/* DMA address array; the first page contains #pages in ~PAGE_MASK */
+	dma_addr_t *addrs;
+};
+
+static void __snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab,
+				       struct snd_dma_sg_fallback *sgbuf)
+{
+	size_t i, size;
+
+	if (sgbuf->pages && sgbuf->addrs) {
+		i = 0;
+		while (i < sgbuf->count) {
+			if (!sgbuf->pages[i] || !sgbuf->addrs[i])
+				break;
+			size = sgbuf->addrs[i] & ~PAGE_MASK;
+			if (WARN_ON(!size))
+				break;
+			if (sgbuf->use_dma_alloc_coherent)
+				dma_free_coherent(dmab->dev.dev, size << PAGE_SHIFT,
+						  page_address(sgbuf->pages[i]),
+						  sgbuf->addrs[i] & PAGE_MASK);
+			else
+				do_free_pages(page_address(sgbuf->pages[i]),
+					      size << PAGE_SHIFT, false);
+			i += size;
+		}
+	}
+	kvfree(sgbuf->pages);
+	kvfree(sgbuf->addrs);
+	kfree(sgbuf);
+}
+
+static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	struct snd_dma_sg_fallback *sgbuf;
+	struct page **pagep, *curp;
+	size_t chunk, npages;
+	dma_addr_t *addrp;
+	dma_addr_t addr;
+	void *p;
+
+	/* correct the type */
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_SG)
+		dmab->dev.type = SNDRV_DMA_TYPE_DEV_SG_FALLBACK;
+	else if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG)
+		dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK;
+
+	sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
+	if (!sgbuf)
+		return NULL;
+	sgbuf->use_dma_alloc_coherent = cpu_feature_enabled(X86_FEATURE_XENPV);
+	size = PAGE_ALIGN(size);
+	sgbuf->count = size >> PAGE_SHIFT;
+	sgbuf->pages = kvcalloc(sgbuf->count, sizeof(*sgbuf->pages), GFP_KERNEL);
+	sgbuf->addrs = kvcalloc(sgbuf->count, sizeof(*sgbuf->addrs), GFP_KERNEL);
+	if (!sgbuf->pages || !sgbuf->addrs)
+		goto error;
+
+	pagep = sgbuf->pages;
+	addrp = sgbuf->addrs;
+	chunk = (PAGE_SIZE - 1) << PAGE_SHIFT; /* to fit in low bits in addrs */
+	while (size > 0) {
+		chunk = min(size, chunk);
+		if (sgbuf->use_dma_alloc_coherent)
+			p = dma_alloc_coherent(dmab->dev.dev, chunk, &addr, DEFAULT_GFP);
+		else
+			p = do_alloc_pages(dmab->dev.dev, chunk, &addr, false);
+		if (!p) {
+			if (chunk <= PAGE_SIZE)
+				goto error;
+			chunk >>= 1;
+			chunk = PAGE_SIZE << get_order(chunk);
+			continue;
+		}
+
+		size -= chunk;
+		/* fill pages */
+		npages = chunk >> PAGE_SHIFT;
+		*addrp = npages; /* store in lower bits */
+		curp = virt_to_page(p);
+		while (npages--) {
+			*pagep++ = curp++;
+			*addrp++ |= addr;
+			addr += PAGE_SIZE;
+		}
+	}
+
+	p = vmap(sgbuf->pages, sgbuf->count, VM_MAP, PAGE_KERNEL);
+	if (!p)
+		goto error;
+
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK)
+		set_pages_array_wc(sgbuf->pages, sgbuf->count);
+
+	dmab->private_data = sgbuf;
+	/* store the first page address for convenience */
+	dmab->addr = sgbuf->addrs[0] & PAGE_MASK;
+	return p;
+
+ error:
+	__snd_dma_sg_fallback_free(dmab, sgbuf);
+	return NULL;
+}
+
+static void snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab)
+{
+	struct snd_dma_sg_fallback *sgbuf = dmab->private_data;
+
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK)
+		set_pages_array_wb(sgbuf->pages, sgbuf->count);
+	vunmap(dmab->area);
+	__snd_dma_sg_fallback_free(dmab, dmab->private_data);
+}
+
+static dma_addr_t snd_dma_sg_fallback_get_addr(struct snd_dma_buffer *dmab,
+					       size_t offset)
+{
+	struct snd_dma_sg_fallback *sgbuf = dmab->private_data;
+	size_t index = offset >> PAGE_SHIFT;
+
+	return (sgbuf->addrs[index] & PAGE_MASK) | (offset & ~PAGE_MASK);
+}
+
+static int snd_dma_sg_fallback_mmap(struct snd_dma_buffer *dmab,
+				    struct vm_area_struct *area)
+{
+	struct snd_dma_sg_fallback *sgbuf = dmab->private_data;
+
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK)
+		area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return vm_map_pages(area, sgbuf->pages, sgbuf->count);
+}
+
+static const struct snd_malloc_ops snd_dma_sg_fallback_ops = {
+	.alloc = snd_dma_sg_fallback_alloc,
+	.free = snd_dma_sg_fallback_free,
+	.mmap = snd_dma_sg_fallback_mmap,
+	.get_addr = snd_dma_sg_fallback_get_addr,
+	/* reuse vmalloc helpers */
+	.get_page = snd_dma_vmalloc_get_page,
+	.get_chunk_size = snd_dma_vmalloc_get_chunk_size,
+};
+#endif /* CONFIG_SND_DMA_SGBUF */
+
+/*
+ * Non-coherent pages allocator
+ */
+static void *snd_dma_noncoherent_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	void *p;
+
+	p = dma_alloc_noncoherent(dmab->dev.dev, size, &dmab->addr,
+				  dmab->dev.dir, DEFAULT_GFP);
+	if (p)
+		dmab->dev.need_sync = dma_need_sync(dmab->dev.dev, dmab->addr);
+	return p;
+}
+
+static void snd_dma_noncoherent_free(struct snd_dma_buffer *dmab)
+{
+	dma_free_noncoherent(dmab->dev.dev, dmab->bytes, dmab->area,
+			     dmab->addr, dmab->dev.dir);
+}
+
+static int snd_dma_noncoherent_mmap(struct snd_dma_buffer *dmab,
+				    struct vm_area_struct *area)
+{
+	area->vm_page_prot = vm_get_page_prot(area->vm_flags);
+	return dma_mmap_pages(dmab->dev.dev, area,
+			      area->vm_end - area->vm_start,
+			      virt_to_page(dmab->area));
+}
+
+static void snd_dma_noncoherent_sync(struct snd_dma_buffer *dmab,
+				     enum snd_dma_sync_mode mode)
+{
+	if (mode == SNDRV_DMA_SYNC_CPU) {
+		if (dmab->dev.dir != DMA_TO_DEVICE)
+			dma_sync_single_for_cpu(dmab->dev.dev, dmab->addr,
+						dmab->bytes, dmab->dev.dir);
+	} else {
+		if (dmab->dev.dir != DMA_FROM_DEVICE)
+			dma_sync_single_for_device(dmab->dev.dev, dmab->addr,
+						   dmab->bytes, dmab->dev.dir);
+	}
+}
+
+static const struct snd_malloc_ops snd_dma_noncoherent_ops = {
+	.alloc = snd_dma_noncoherent_alloc,
+	.free = snd_dma_noncoherent_free,
+	.mmap = snd_dma_noncoherent_mmap,
+	.sync = snd_dma_noncoherent_sync,
+};
+
+#endif /* CONFIG_HAS_DMA */
+
+/*
+ * Entry points
+ */
+static const struct snd_malloc_ops *snd_dma_ops[] = {
+	[SNDRV_DMA_TYPE_CONTINUOUS] = &snd_dma_continuous_ops,
+	[SNDRV_DMA_TYPE_VMALLOC] = &snd_dma_vmalloc_ops,
+#ifdef CONFIG_HAS_DMA
+	[SNDRV_DMA_TYPE_DEV] = &snd_dma_dev_ops,
+	[SNDRV_DMA_TYPE_DEV_WC] = &snd_dma_wc_ops,
+	[SNDRV_DMA_TYPE_NONCONTIG] = &snd_dma_noncontig_ops,
+	[SNDRV_DMA_TYPE_NONCOHERENT] = &snd_dma_noncoherent_ops,
+#ifdef CONFIG_SND_DMA_SGBUF
+	[SNDRV_DMA_TYPE_DEV_WC_SG] = &snd_dma_sg_wc_ops,
+#endif
+#ifdef CONFIG_GENERIC_ALLOCATOR
+	[SNDRV_DMA_TYPE_DEV_IRAM] = &snd_dma_iram_ops,
+#endif /* CONFIG_GENERIC_ALLOCATOR */
+#ifdef CONFIG_SND_DMA_SGBUF
+	[SNDRV_DMA_TYPE_DEV_SG_FALLBACK] = &snd_dma_sg_fallback_ops,
+	[SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK] = &snd_dma_sg_fallback_ops,
+#endif
+#endif /* CONFIG_HAS_DMA */
+};
+
+static const struct snd_malloc_ops *snd_dma_get_ops(struct snd_dma_buffer *dmab)
+{
+	if (WARN_ON_ONCE(!dmab))
+		return NULL;
+	if (WARN_ON_ONCE(dmab->dev.type <= SNDRV_DMA_TYPE_UNKNOWN ||
+			 dmab->dev.type >= ARRAY_SIZE(snd_dma_ops)))
+		return NULL;
+	return snd_dma_ops[dmab->dev.type];
+}
diff --git a/sound/core/memalloc_local.h b/sound/core/memalloc_local.h
new file mode 100644
index 0000000000..8b19f3a68a
--- /dev/null
+++ b/sound/core/memalloc_local.h
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#ifndef __MEMALLOC_LOCAL_H
+#define __MEMALLOC_LOCAL_H
+
+struct snd_malloc_ops {
+	void *(*alloc)(struct snd_dma_buffer *dmab, size_t size);
+	void (*free)(struct snd_dma_buffer *dmab);
+	dma_addr_t (*get_addr)(struct snd_dma_buffer *dmab, size_t offset);
+	struct page *(*get_page)(struct snd_dma_buffer *dmab, size_t offset);
+	unsigned int (*get_chunk_size)(struct snd_dma_buffer *dmab,
+				       unsigned int ofs, unsigned int size);
+	int (*mmap)(struct snd_dma_buffer *dmab, struct vm_area_struct *area);
+	void (*sync)(struct snd_dma_buffer *dmab, enum snd_dma_sync_mode mode);
+};
+
+#endif /* __MEMALLOC_LOCAL_H */
diff --git a/sound/core/memory.c b/sound/core/memory.c
new file mode 100644
index 0000000000..2d2d0094c8
--- /dev/null
+++ b/sound/core/memory.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ * 
+ *  Misc memory accessors
+ */
+
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+/**
+ * copy_to_user_fromio - copy data from mmio-space to user-space
+ * @dst: the destination pointer on user-space
+ * @src: the source pointer on mmio
+ * @count: the data size to copy in bytes
+ *
+ * Copies the data from mmio-space to user-space.
+ *
+ * Return: Zero if successful, or non-zero on failure.
+ */
+int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
+{
+	struct iov_iter iter;
+
+	if (import_ubuf(ITER_DEST, dst, count, &iter))
+		return -EFAULT;
+	return copy_to_iter_fromio(&iter, (const void __iomem *)src, count);
+}
+EXPORT_SYMBOL(copy_to_user_fromio);
+
+/**
+ * copy_to_iter_fromio - copy data from mmio-space to iov_iter
+ * @dst: the destination iov_iter
+ * @src: the source pointer on mmio
+ * @count: the data size to copy in bytes
+ *
+ * Copies the data from mmio-space to iov_iter.
+ *
+ * Return: Zero if successful, or non-zero on failure.
+ */
+int copy_to_iter_fromio(struct iov_iter *dst, const void __iomem *src,
+			size_t count)
+{
+#if defined(__i386__) || defined(CONFIG_SPARC32)
+	return copy_to_iter((const void __force *)src, count, dst) == count ? 0 : -EFAULT;
+#else
+	char buf[256];
+	while (count) {
+		size_t c = count;
+		if (c > sizeof(buf))
+			c = sizeof(buf);
+		memcpy_fromio(buf, (void __iomem *)src, c);
+		if (copy_to_iter(buf, c, dst) != c)
+			return -EFAULT;
+		count -= c;
+		src += c;
+	}
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(copy_to_iter_fromio);
+
+/**
+ * copy_from_user_toio - copy data from user-space to mmio-space
+ * @dst: the destination pointer on mmio-space
+ * @src: the source pointer on user-space
+ * @count: the data size to copy in bytes
+ *
+ * Copies the data from user-space to mmio-space.
+ *
+ * Return: Zero if successful, or non-zero on failure.
+ */
+int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
+{
+	struct iov_iter iter;
+
+	if (import_ubuf(ITER_SOURCE, (void __user *)src, count, &iter))
+		return -EFAULT;
+	return copy_from_iter_toio((void __iomem *)dst, &iter, count);
+}
+EXPORT_SYMBOL(copy_from_user_toio);
+
+/**
+ * copy_from_iter_toio - copy data from iov_iter to mmio-space
+ * @dst: the destination pointer on mmio-space
+ * @src: the source iov_iter
+ * @count: the data size to copy in bytes
+ *
+ * Copies the data from iov_iter to mmio-space.
+ *
+ * Return: Zero if successful, or non-zero on failure.
+ */
+int copy_from_iter_toio(void __iomem *dst, struct iov_iter *src, size_t count)
+{
+#if defined(__i386__) || defined(CONFIG_SPARC32)
+	return copy_from_iter((void __force *)dst, count, src) == count ? 0 : -EFAULT;
+#else
+	char buf[256];
+	while (count) {
+		size_t c = count;
+		if (c > sizeof(buf))
+			c = sizeof(buf);
+		if (copy_from_iter(buf, c, src) != c)
+			return -EFAULT;
+		memcpy_toio(dst, buf, c);
+		count -= c;
+		dst += c;
+	}
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(copy_from_iter_toio);
diff --git a/sound/core/misc.c b/sound/core/misc.c
new file mode 100644
index 0000000000..d32a19976a
--- /dev/null
+++ b/sound/core/misc.c
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Misc and compatibility things
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/moduleparam.h>
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/fs.h>
+#include <sound/core.h>
+
+#ifdef CONFIG_SND_DEBUG
+
+#ifdef CONFIG_SND_DEBUG_VERBOSE
+#define DEFAULT_DEBUG_LEVEL	2
+#else
+#define DEFAULT_DEBUG_LEVEL	1
+#endif
+
+static int debug = DEFAULT_DEBUG_LEVEL;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Debug level (0 = disable)");
+
+#endif /* CONFIG_SND_DEBUG */
+
+void release_and_free_resource(struct resource *res)
+{
+	if (res) {
+		release_resource(res);
+		kfree(res);
+	}
+}
+EXPORT_SYMBOL(release_and_free_resource);
+
+#ifdef CONFIG_SND_VERBOSE_PRINTK
+/* strip the leading path if the given path is absolute */
+static const char *sanity_file_name(const char *path)
+{
+	if (*path == '/')
+		return strrchr(path, '/') + 1;
+	else
+		return path;
+}
+#endif
+
+#if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
+void __snd_printk(unsigned int level, const char *path, int line,
+		  const char *format, ...)
+{
+	va_list args;
+#ifdef CONFIG_SND_VERBOSE_PRINTK
+	int kern_level;
+	struct va_format vaf;
+	char verbose_fmt[] = KERN_DEFAULT "ALSA %s:%d %pV";
+	bool level_found = false;
+#endif
+
+#ifdef CONFIG_SND_DEBUG
+	if (debug < level)
+		return;
+#endif
+
+	va_start(args, format);
+#ifdef CONFIG_SND_VERBOSE_PRINTK
+	vaf.fmt = format;
+	vaf.va = &args;
+
+	while ((kern_level = printk_get_level(vaf.fmt)) != 0) {
+		const char *end_of_header = printk_skip_level(vaf.fmt);
+
+		/* Ignore KERN_CONT. We print filename:line for each piece. */
+		if (kern_level >= '0' && kern_level <= '7') {
+			memcpy(verbose_fmt, vaf.fmt, end_of_header - vaf.fmt);
+			level_found = true;
+		}
+
+		vaf.fmt = end_of_header;
+	}
+
+	if (!level_found && level)
+		memcpy(verbose_fmt, KERN_DEBUG, sizeof(KERN_DEBUG) - 1);
+
+	printk(verbose_fmt, sanity_file_name(path), line, &vaf);
+#else
+	vprintk(format, args);
+#endif
+	va_end(args);
+}
+EXPORT_SYMBOL_GPL(__snd_printk);
+#endif
+
+#ifdef CONFIG_PCI
+#include <linux/pci.h>
+/**
+ * snd_pci_quirk_lookup_id - look up a PCI SSID quirk list
+ * @vendor: PCI SSV id
+ * @device: PCI SSD id
+ * @list: quirk list, terminated by a null entry
+ *
+ * Look through the given quirk list and finds a matching entry
+ * with the same PCI SSID.  When subdevice is 0, all subdevice
+ * values may match.
+ *
+ * Returns the matched entry pointer, or NULL if nothing matched.
+ */
+const struct snd_pci_quirk *
+snd_pci_quirk_lookup_id(u16 vendor, u16 device,
+			const struct snd_pci_quirk *list)
+{
+	const struct snd_pci_quirk *q;
+
+	for (q = list; q->subvendor || q->subdevice; q++) {
+		if (q->subvendor != vendor)
+			continue;
+		if (!q->subdevice ||
+		    (device & q->subdevice_mask) == q->subdevice)
+			return q;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(snd_pci_quirk_lookup_id);
+
+/**
+ * snd_pci_quirk_lookup - look up a PCI SSID quirk list
+ * @pci: pci_dev handle
+ * @list: quirk list, terminated by a null entry
+ *
+ * Look through the given quirk list and finds a matching entry
+ * with the same PCI SSID.  When subdevice is 0, all subdevice
+ * values may match.
+ *
+ * Returns the matched entry pointer, or NULL if nothing matched.
+ */
+const struct snd_pci_quirk *
+snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
+{
+	if (!pci)
+		return NULL;
+	return snd_pci_quirk_lookup_id(pci->subsystem_vendor,
+				       pci->subsystem_device,
+				       list);
+}
+EXPORT_SYMBOL(snd_pci_quirk_lookup);
+#endif
+
+/*
+ * Deferred async signal helpers
+ *
+ * Below are a few helper functions to wrap the async signal handling
+ * in the deferred work.  The main purpose is to avoid the messy deadlock
+ * around tasklist_lock and co at the kill_fasync() invocation.
+ * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper()
+ * and snd_kill_fasync(), respectively.  In addition, snd_fasync_free() has
+ * to be called at releasing the relevant file object.
+ */
+struct snd_fasync {
+	struct fasync_struct *fasync;
+	int signal;
+	int poll;
+	int on;
+	struct list_head list;
+};
+
+static DEFINE_SPINLOCK(snd_fasync_lock);
+static LIST_HEAD(snd_fasync_list);
+
+static void snd_fasync_work_fn(struct work_struct *work)
+{
+	struct snd_fasync *fasync;
+
+	spin_lock_irq(&snd_fasync_lock);
+	while (!list_empty(&snd_fasync_list)) {
+		fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list);
+		list_del_init(&fasync->list);
+		spin_unlock_irq(&snd_fasync_lock);
+		if (fasync->on)
+			kill_fasync(&fasync->fasync, fasync->signal, fasync->poll);
+		spin_lock_irq(&snd_fasync_lock);
+	}
+	spin_unlock_irq(&snd_fasync_lock);
+}
+
+static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn);
+
+int snd_fasync_helper(int fd, struct file *file, int on,
+		      struct snd_fasync **fasyncp)
+{
+	struct snd_fasync *fasync = NULL;
+
+	if (on) {
+		fasync = kzalloc(sizeof(*fasync), GFP_KERNEL);
+		if (!fasync)
+			return -ENOMEM;
+		INIT_LIST_HEAD(&fasync->list);
+	}
+
+	spin_lock_irq(&snd_fasync_lock);
+	if (*fasyncp) {
+		kfree(fasync);
+		fasync = *fasyncp;
+	} else {
+		if (!fasync) {
+			spin_unlock_irq(&snd_fasync_lock);
+			return 0;
+		}
+		*fasyncp = fasync;
+	}
+	fasync->on = on;
+	spin_unlock_irq(&snd_fasync_lock);
+	return fasync_helper(fd, file, on, &fasync->fasync);
+}
+EXPORT_SYMBOL_GPL(snd_fasync_helper);
+
+void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)
+{
+	unsigned long flags;
+
+	if (!fasync || !fasync->on)
+		return;
+	spin_lock_irqsave(&snd_fasync_lock, flags);
+	fasync->signal = signal;
+	fasync->poll = poll;
+	list_move(&fasync->list, &snd_fasync_list);
+	schedule_work(&snd_fasync_work);
+	spin_unlock_irqrestore(&snd_fasync_lock, flags);
+}
+EXPORT_SYMBOL_GPL(snd_kill_fasync);
+
+void snd_fasync_free(struct snd_fasync *fasync)
+{
+	if (!fasync)
+		return;
+	fasync->on = 0;
+	flush_work(&snd_fasync_work);
+	kfree(fasync);
+}
+EXPORT_SYMBOL_GPL(snd_fasync_free);
diff --git a/sound/core/oss/Makefile b/sound/core/oss/Makefile
new file mode 100644
index 0000000000..ae25edcc3b
--- /dev/null
+++ b/sound/core/oss/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for ALSA
+# Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-mixer-oss-objs := mixer_oss.o
+
+snd-pcm-oss-y := pcm_oss.o
+snd-pcm-oss-$(CONFIG_SND_PCM_OSS_PLUGINS) += pcm_plugin.o \
+	io.o copy.o linear.o mulaw.o route.o rate.o
+
+obj-$(CONFIG_SND_MIXER_OSS) += snd-mixer-oss.o
+obj-$(CONFIG_SND_PCM_OSS) += snd-pcm-oss.o
diff --git a/sound/core/oss/copy.c b/sound/core/oss/copy.c
new file mode 100644
index 0000000000..05b58d4fc2
--- /dev/null
+++ b/sound/core/oss/copy.c
@@ -0,0 +1,92 @@
+/*
+ *  Linear conversion Plug-In
+ *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+static snd_pcm_sframes_t copy_transfer(struct snd_pcm_plugin *plugin,
+			     const struct snd_pcm_plugin_channel *src_channels,
+			     struct snd_pcm_plugin_channel *dst_channels,
+			     snd_pcm_uframes_t frames)
+{
+	unsigned int channel;
+	unsigned int nchannels;
+
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+	nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; channel++) {
+		if (snd_BUG_ON(src_channels->area.first % 8 ||
+			       src_channels->area.step % 8))
+			return -ENXIO;
+		if (snd_BUG_ON(dst_channels->area.first % 8 ||
+			       dst_channels->area.step % 8))
+			return -ENXIO;
+		if (!src_channels->enabled) {
+			if (dst_channels->wanted)
+				snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format);
+			dst_channels->enabled = 0;
+			continue;
+		}
+		dst_channels->enabled = 1;
+		snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format);
+		src_channels++;
+		dst_channels++;
+	}
+	return frames;
+}
+
+int snd_pcm_plugin_build_copy(struct snd_pcm_substream *plug,
+			      struct snd_pcm_plugin_format *src_format,
+			      struct snd_pcm_plugin_format *dst_format,
+			      struct snd_pcm_plugin **r_plugin)
+{
+	int err;
+	struct snd_pcm_plugin *plugin;
+	int width;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+
+	if (snd_BUG_ON(src_format->format != dst_format->format))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->rate != dst_format->rate))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->channels != dst_format->channels))
+		return -ENXIO;
+
+	width = snd_pcm_format_physical_width(src_format->format);
+	if (snd_BUG_ON(width <= 0))
+		return -ENXIO;
+
+	err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format,
+				   0, &plugin);
+	if (err < 0)
+		return err;
+	plugin->transfer = copy_transfer;
+	*r_plugin = plugin;
+	return 0;
+}
diff --git a/sound/core/oss/io.c b/sound/core/oss/io.c
new file mode 100644
index 0000000000..d870b2d931
--- /dev/null
+++ b/sound/core/oss/io.c
@@ -0,0 +1,141 @@
+/*
+ *  PCM I/O Plug-In Interface
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+  
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include "pcm_plugin.h"
+
+#define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1)
+#define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count)
+#define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1)
+#define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count)
+
+/*
+ *  Basic io plugin
+ */
+ 
+static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin,
+				    const struct snd_pcm_plugin_channel *src_channels,
+				    struct snd_pcm_plugin_channel *dst_channels,
+				    snd_pcm_uframes_t frames)
+{
+	if (snd_BUG_ON(!plugin))
+		return -ENXIO;
+	if (snd_BUG_ON(!src_channels))
+		return -ENXIO;
+	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
+		return pcm_write(plugin->plug, src_channels->area.addr, frames);
+	} else {
+		int channel, channels = plugin->dst_format.channels;
+		void **bufs = (void**)plugin->extra_data;
+		if (snd_BUG_ON(!bufs))
+			return -ENXIO;
+		for (channel = 0; channel < channels; channel++) {
+			if (src_channels[channel].enabled)
+				bufs[channel] = src_channels[channel].area.addr;
+			else
+				bufs[channel] = NULL;
+		}
+		return pcm_writev(plugin->plug, bufs, frames);
+	}
+}
+ 
+static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin,
+				   const struct snd_pcm_plugin_channel *src_channels,
+				   struct snd_pcm_plugin_channel *dst_channels,
+				   snd_pcm_uframes_t frames)
+{
+	if (snd_BUG_ON(!plugin))
+		return -ENXIO;
+	if (snd_BUG_ON(!dst_channels))
+		return -ENXIO;
+	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
+		return pcm_read(plugin->plug, dst_channels->area.addr, frames);
+	} else {
+		int channel, channels = plugin->dst_format.channels;
+		void **bufs = (void**)plugin->extra_data;
+		if (snd_BUG_ON(!bufs))
+			return -ENXIO;
+		for (channel = 0; channel < channels; channel++) {
+			if (dst_channels[channel].enabled)
+				bufs[channel] = dst_channels[channel].area.addr;
+			else
+				bufs[channel] = NULL;
+		}
+		return pcm_readv(plugin->plug, bufs, frames);
+	}
+	return 0;
+}
+ 
+static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin,
+			     snd_pcm_uframes_t frames,
+			     struct snd_pcm_plugin_channel **channels)
+{
+	int err;
+	unsigned int channel;
+	struct snd_pcm_plugin_channel *v;
+	err = snd_pcm_plugin_client_channels(plugin, frames, &v);
+	if (err < 0)
+		return err;
+	*channels = v;
+	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
+		for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v)
+			v->wanted = 1;
+	}
+	return frames;
+}
+
+int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug,
+			    struct snd_pcm_hw_params *params,
+			    struct snd_pcm_plugin **r_plugin)
+{
+	int err;
+	struct snd_pcm_plugin_format format;
+	struct snd_pcm_plugin *plugin;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+	if (snd_BUG_ON(!plug || !params))
+		return -ENXIO;
+	format.format = params_format(params);
+	format.rate = params_rate(params);
+	format.channels = params_channels(params);
+	err = snd_pcm_plugin_build(plug, "I/O io",
+				   &format, &format,
+				   sizeof(void *) * format.channels,
+				   &plugin);
+	if (err < 0)
+		return err;
+	plugin->access = params_access(params);
+	if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
+		plugin->transfer = io_playback_transfer;
+		if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)
+			plugin->client_channels = io_src_channels;
+	} else {
+		plugin->transfer = io_capture_transfer;
+	}
+
+	*r_plugin = plugin;
+	return 0;
+}
diff --git a/sound/core/oss/linear.c b/sound/core/oss/linear.c
new file mode 100644
index 0000000000..797d838a2f
--- /dev/null
+++ b/sound/core/oss/linear.c
@@ -0,0 +1,180 @@
+/*
+ *  Linear conversion Plug-In
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>,
+ *			  Abramo Bagnara <abramo@alsa-project.org>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+/*
+ *  Basic linear conversion plugin
+ */
+ 
+struct linear_priv {
+	int cvt_endian;		/* need endian conversion? */
+	unsigned int src_ofs;	/* byte offset in source format */
+	unsigned int dst_ofs;	/* byte soffset in destination format */
+	unsigned int copy_ofs;	/* byte offset in temporary u32 data */
+	unsigned int dst_bytes;		/* byte size of destination format */
+	unsigned int copy_bytes;	/* bytes to copy per conversion */
+	unsigned int flip; /* MSB flip for signeness, done after endian conv */
+};
+
+static inline void do_convert(struct linear_priv *data,
+			      unsigned char *dst, unsigned char *src)
+{
+	unsigned int tmp = 0;
+	unsigned char *p = (unsigned char *)&tmp;
+
+	memcpy(p + data->copy_ofs, src + data->src_ofs, data->copy_bytes);
+	if (data->cvt_endian)
+		tmp = swab32(tmp);
+	tmp ^= data->flip;
+	memcpy(dst, p + data->dst_ofs, data->dst_bytes);
+}
+
+static void convert(struct snd_pcm_plugin *plugin,
+		    const struct snd_pcm_plugin_channel *src_channels,
+		    struct snd_pcm_plugin_channel *dst_channels,
+		    snd_pcm_uframes_t frames)
+{
+	struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
+	int channel;
+	int nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		snd_pcm_uframes_t frames1;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
+		dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
+		src_step = src_channels[channel].area.step / 8;
+		dst_step = dst_channels[channel].area.step / 8;
+		frames1 = frames;
+		while (frames1-- > 0) {
+			do_convert(data, dst, src);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin,
+			       const struct snd_pcm_plugin_channel *src_channels,
+			       struct snd_pcm_plugin_channel *dst_channels,
+			       snd_pcm_uframes_t frames)
+{
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+#ifdef CONFIG_SND_DEBUG
+	{
+		unsigned int channel;
+		for (channel = 0; channel < plugin->src_format.channels; channel++) {
+			if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
+				       src_channels[channel].area.step % 8))
+				return -ENXIO;
+			if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
+				       dst_channels[channel].area.step % 8))
+				return -ENXIO;
+		}
+	}
+#endif
+	if (frames > dst_channels[0].frames)
+		frames = dst_channels[0].frames;
+	convert(plugin, src_channels, dst_channels, frames);
+	return frames;
+}
+
+static void init_data(struct linear_priv *data,
+		      snd_pcm_format_t src_format, snd_pcm_format_t dst_format)
+{
+	int src_le, dst_le, src_bytes, dst_bytes;
+
+	src_bytes = snd_pcm_format_width(src_format) / 8;
+	dst_bytes = snd_pcm_format_width(dst_format) / 8;
+	src_le = snd_pcm_format_little_endian(src_format) > 0;
+	dst_le = snd_pcm_format_little_endian(dst_format) > 0;
+
+	data->dst_bytes = dst_bytes;
+	data->cvt_endian = src_le != dst_le;
+	data->copy_bytes = src_bytes < dst_bytes ? src_bytes : dst_bytes;
+	if (src_le) {
+		data->copy_ofs = 4 - data->copy_bytes;
+		data->src_ofs = src_bytes - data->copy_bytes;
+	} else
+		data->src_ofs = snd_pcm_format_physical_width(src_format) / 8 -
+			src_bytes;
+	if (dst_le)
+		data->dst_ofs = 4 - data->dst_bytes;
+	else
+		data->dst_ofs = snd_pcm_format_physical_width(dst_format) / 8 -
+			dst_bytes;
+	if (snd_pcm_format_signed(src_format) !=
+	    snd_pcm_format_signed(dst_format)) {
+		if (dst_le)
+			data->flip = (__force u32)cpu_to_le32(0x80000000);
+		else
+			data->flip = (__force u32)cpu_to_be32(0x80000000);
+	}
+}
+
+int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug,
+				struct snd_pcm_plugin_format *src_format,
+				struct snd_pcm_plugin_format *dst_format,
+				struct snd_pcm_plugin **r_plugin)
+{
+	int err;
+	struct linear_priv *data;
+	struct snd_pcm_plugin *plugin;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+
+	if (snd_BUG_ON(src_format->rate != dst_format->rate))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->channels != dst_format->channels))
+		return -ENXIO;
+	if (snd_BUG_ON(!snd_pcm_format_linear(src_format->format) ||
+		       !snd_pcm_format_linear(dst_format->format)))
+		return -ENXIO;
+
+	err = snd_pcm_plugin_build(plug, "linear format conversion",
+				   src_format, dst_format,
+				   sizeof(struct linear_priv), &plugin);
+	if (err < 0)
+		return err;
+	data = (struct linear_priv *)plugin->extra_data;
+	init_data(data, src_format->format, dst_format->format);
+	plugin->transfer = linear_transfer;
+	*r_plugin = plugin;
+	return 0;
+}
diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c
new file mode 100644
index 0000000000..dae2da3808
--- /dev/null
+++ b/sound/core/oss/mixer_oss.c
@@ -0,0 +1,1460 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  OSS emulation layer for the mixer interface
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <linux/compat.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/control.h>
+#include <sound/info.h>
+#include <sound/mixer_oss.h>
+#include <linux/soundcard.h>
+
+#define OSS_ALSAEMULVER         _SIOR ('M', 249, int)
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Mixer OSS emulation for ALSA.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_MIXER);
+
+static int snd_mixer_oss_open(struct inode *inode, struct file *file)
+{
+	struct snd_card *card;
+	struct snd_mixer_oss_file *fmixer;
+	int err;
+
+	err = nonseekable_open(inode, file);
+	if (err < 0)
+		return err;
+
+	card = snd_lookup_oss_minor_data(iminor(inode),
+					 SNDRV_OSS_DEVICE_TYPE_MIXER);
+	if (card == NULL)
+		return -ENODEV;
+	if (card->mixer_oss == NULL) {
+		snd_card_unref(card);
+		return -ENODEV;
+	}
+	err = snd_card_file_add(card, file);
+	if (err < 0) {
+		snd_card_unref(card);
+		return err;
+	}
+	fmixer = kzalloc(sizeof(*fmixer), GFP_KERNEL);
+	if (fmixer == NULL) {
+		snd_card_file_remove(card, file);
+		snd_card_unref(card);
+		return -ENOMEM;
+	}
+	fmixer->card = card;
+	fmixer->mixer = card->mixer_oss;
+	file->private_data = fmixer;
+	if (!try_module_get(card->module)) {
+		kfree(fmixer);
+		snd_card_file_remove(card, file);
+		snd_card_unref(card);
+		return -EFAULT;
+	}
+	snd_card_unref(card);
+	return 0;
+}
+
+static int snd_mixer_oss_release(struct inode *inode, struct file *file)
+{
+	struct snd_mixer_oss_file *fmixer;
+
+	if (file->private_data) {
+		fmixer = file->private_data;
+		module_put(fmixer->card->module);
+		snd_card_file_remove(fmixer->card, file);
+		kfree(fmixer);
+	}
+	return 0;
+}
+
+static int snd_mixer_oss_info(struct snd_mixer_oss_file *fmixer,
+			      mixer_info __user *_info)
+{
+	struct snd_card *card = fmixer->card;
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct mixer_info info;
+	
+	memset(&info, 0, sizeof(info));
+	strscpy(info.id, mixer && mixer->id[0] ? mixer->id : card->driver, sizeof(info.id));
+	strscpy(info.name, mixer && mixer->name[0] ? mixer->name : card->mixername, sizeof(info.name));
+	info.modify_counter = card->mixer_oss_change_count;
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_mixer_oss_info_obsolete(struct snd_mixer_oss_file *fmixer,
+				       _old_mixer_info __user *_info)
+{
+	struct snd_card *card = fmixer->card;
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	_old_mixer_info info;
+	
+	memset(&info, 0, sizeof(info));
+	strscpy(info.id, mixer && mixer->id[0] ? mixer->id : card->driver, sizeof(info.id));
+	strscpy(info.name, mixer && mixer->name[0] ? mixer->name : card->mixername, sizeof(info.name));
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_mixer_oss_caps(struct snd_mixer_oss_file *fmixer)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	int result = 0;
+
+	if (mixer == NULL)
+		return -EIO;
+	if (mixer->get_recsrc && mixer->put_recsrc)
+		result |= SOUND_CAP_EXCL_INPUT;
+	return result;
+}
+
+static int snd_mixer_oss_devmask(struct snd_mixer_oss_file *fmixer)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_mixer_oss_slot *pslot;
+	int result = 0, chn;
+
+	if (mixer == NULL)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	for (chn = 0; chn < 31; chn++) {
+		pslot = &mixer->slots[chn];
+		if (pslot->put_volume || pslot->put_recsrc)
+			result |= 1 << chn;
+	}
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_stereodevs(struct snd_mixer_oss_file *fmixer)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_mixer_oss_slot *pslot;
+	int result = 0, chn;
+
+	if (mixer == NULL)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	for (chn = 0; chn < 31; chn++) {
+		pslot = &mixer->slots[chn];
+		if (pslot->put_volume && pslot->stereo)
+			result |= 1 << chn;
+	}
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_recmask(struct snd_mixer_oss_file *fmixer)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	int result = 0;
+
+	if (mixer == NULL)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	if (mixer->put_recsrc && mixer->get_recsrc) {	/* exclusive */
+		result = mixer->mask_recsrc;
+	} else {
+		struct snd_mixer_oss_slot *pslot;
+		int chn;
+		for (chn = 0; chn < 31; chn++) {
+			pslot = &mixer->slots[chn];
+			if (pslot->put_recsrc)
+				result |= 1 << chn;
+		}
+	}
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_get_recsrc(struct snd_mixer_oss_file *fmixer)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	int result = 0;
+
+	if (mixer == NULL)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	if (mixer->put_recsrc && mixer->get_recsrc) {	/* exclusive */
+		unsigned int index;
+		result = mixer->get_recsrc(fmixer, &index);
+		if (result < 0)
+			goto unlock;
+		result = 1 << index;
+	} else {
+		struct snd_mixer_oss_slot *pslot;
+		int chn;
+		for (chn = 0; chn < 31; chn++) {
+			pslot = &mixer->slots[chn];
+			if (pslot->get_recsrc) {
+				int active = 0;
+				pslot->get_recsrc(fmixer, pslot, &active);
+				if (active)
+					result |= 1 << chn;
+			}
+		}
+	}
+	mixer->oss_recsrc = result;
+ unlock:
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_set_recsrc(struct snd_mixer_oss_file *fmixer, int recsrc)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_mixer_oss_slot *pslot;
+	int chn, active;
+	unsigned int index;
+	int result = 0;
+
+	if (mixer == NULL)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	if (mixer->get_recsrc && mixer->put_recsrc) {	/* exclusive input */
+		if (recsrc & ~mixer->oss_recsrc)
+			recsrc &= ~mixer->oss_recsrc;
+		mixer->put_recsrc(fmixer, ffz(~recsrc));
+		mixer->get_recsrc(fmixer, &index);
+		result = 1 << index;
+	}
+	for (chn = 0; chn < 31; chn++) {
+		pslot = &mixer->slots[chn];
+		if (pslot->put_recsrc) {
+			active = (recsrc & (1 << chn)) ? 1 : 0;
+			pslot->put_recsrc(fmixer, pslot, active);
+		}
+	}
+	if (! result) {
+		for (chn = 0; chn < 31; chn++) {
+			pslot = &mixer->slots[chn];
+			if (pslot->get_recsrc) {
+				active = 0;
+				pslot->get_recsrc(fmixer, pslot, &active);
+				if (active)
+					result |= 1 << chn;
+			}
+		}
+	}
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_get_volume(struct snd_mixer_oss_file *fmixer, int slot)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_mixer_oss_slot *pslot;
+	int result = 0, left, right;
+
+	if (mixer == NULL || slot > 30)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	pslot = &mixer->slots[slot];
+	left = pslot->volume[0];
+	right = pslot->volume[1];
+	if (pslot->get_volume)
+		result = pslot->get_volume(fmixer, pslot, &left, &right);
+	if (!pslot->stereo)
+		right = left;
+	if (snd_BUG_ON(left < 0 || left > 100)) {
+		result = -EIO;
+		goto unlock;
+	}
+	if (snd_BUG_ON(right < 0 || right > 100)) {
+		result = -EIO;
+		goto unlock;
+	}
+	if (result >= 0) {
+		pslot->volume[0] = left;
+		pslot->volume[1] = right;
+	 	result = (left & 0xff) | ((right & 0xff) << 8);
+	}
+ unlock:
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_set_volume(struct snd_mixer_oss_file *fmixer,
+				    int slot, int volume)
+{
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_mixer_oss_slot *pslot;
+	int result = 0, left = volume & 0xff, right = (volume >> 8) & 0xff;
+
+	if (mixer == NULL || slot > 30)
+		return -EIO;
+	mutex_lock(&mixer->reg_mutex);
+	pslot = &mixer->slots[slot];
+	if (left > 100)
+		left = 100;
+	if (right > 100)
+		right = 100;
+	if (!pslot->stereo)
+		right = left;
+	if (pslot->put_volume)
+		result = pslot->put_volume(fmixer, pslot, left, right);
+	if (result < 0)
+		goto unlock;
+	pslot->volume[0] = left;
+	pslot->volume[1] = right;
+	result = (left & 0xff) | ((right & 0xff) << 8);
+ unlock:
+	mutex_unlock(&mixer->reg_mutex);
+	return result;
+}
+
+static int snd_mixer_oss_ioctl1(struct snd_mixer_oss_file *fmixer, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	int tmp;
+
+	if (snd_BUG_ON(!fmixer))
+		return -ENXIO;
+	if (((cmd >> 8) & 0xff) == 'M') {
+		switch (cmd) {
+		case SOUND_MIXER_INFO:
+			return snd_mixer_oss_info(fmixer, argp);
+		case SOUND_OLD_MIXER_INFO:
+ 			return snd_mixer_oss_info_obsolete(fmixer, argp);
+		case SOUND_MIXER_WRITE_RECSRC:
+			if (get_user(tmp, p))
+				return -EFAULT;
+			tmp = snd_mixer_oss_set_recsrc(fmixer, tmp);
+			if (tmp < 0)
+				return tmp;
+			return put_user(tmp, p);
+		case OSS_GETVERSION:
+			return put_user(SNDRV_OSS_VERSION, p);
+		case OSS_ALSAEMULVER:
+			return put_user(1, p);
+		case SOUND_MIXER_READ_DEVMASK:
+			tmp = snd_mixer_oss_devmask(fmixer);
+			if (tmp < 0)
+				return tmp;
+			return put_user(tmp, p);
+		case SOUND_MIXER_READ_STEREODEVS:
+			tmp = snd_mixer_oss_stereodevs(fmixer);
+			if (tmp < 0)
+				return tmp;
+			return put_user(tmp, p);
+		case SOUND_MIXER_READ_RECMASK:
+			tmp = snd_mixer_oss_recmask(fmixer);
+			if (tmp < 0)
+				return tmp;
+			return put_user(tmp, p);
+		case SOUND_MIXER_READ_CAPS:
+			tmp = snd_mixer_oss_caps(fmixer);
+			if (tmp < 0)
+				return tmp;
+			return put_user(tmp, p);
+		case SOUND_MIXER_READ_RECSRC:
+			tmp = snd_mixer_oss_get_recsrc(fmixer);
+			if (tmp < 0)
+				return tmp;
+			return put_user(tmp, p);
+		}
+	}
+	if (cmd & SIOC_IN) {
+		if (get_user(tmp, p))
+			return -EFAULT;
+		tmp = snd_mixer_oss_set_volume(fmixer, cmd & 0xff, tmp);
+		if (tmp < 0)
+			return tmp;
+		return put_user(tmp, p);
+	} else if (cmd & SIOC_OUT) {
+		tmp = snd_mixer_oss_get_volume(fmixer, cmd & 0xff);
+		if (tmp < 0)
+			return tmp;
+		return put_user(tmp, p);
+	}
+	return -ENXIO;
+}
+
+static long snd_mixer_oss_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	return snd_mixer_oss_ioctl1(file->private_data, cmd, arg);
+}
+
+int snd_mixer_oss_ioctl_card(struct snd_card *card, unsigned int cmd, unsigned long arg)
+{
+	struct snd_mixer_oss_file fmixer;
+	
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+	if (card->mixer_oss == NULL)
+		return -ENXIO;
+	memset(&fmixer, 0, sizeof(fmixer));
+	fmixer.card = card;
+	fmixer.mixer = card->mixer_oss;
+	return snd_mixer_oss_ioctl1(&fmixer, cmd, arg);
+}
+EXPORT_SYMBOL(snd_mixer_oss_ioctl_card);
+
+#ifdef CONFIG_COMPAT
+/* all compatible */
+static long snd_mixer_oss_ioctl_compat(struct file *file, unsigned int cmd,
+				       unsigned long arg)
+{
+	return snd_mixer_oss_ioctl1(file->private_data, cmd,
+				    (unsigned long)compat_ptr(arg));
+}
+#else
+#define snd_mixer_oss_ioctl_compat	NULL
+#endif
+
+/*
+ *  REGISTRATION PART
+ */
+
+static const struct file_operations snd_mixer_oss_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.open =		snd_mixer_oss_open,
+	.release =	snd_mixer_oss_release,
+	.llseek =	no_llseek,
+	.unlocked_ioctl =	snd_mixer_oss_ioctl,
+	.compat_ioctl =	snd_mixer_oss_ioctl_compat,
+};
+
+/*
+ *  utilities
+ */
+
+static long snd_mixer_oss_conv(long val, long omin, long omax, long nmin, long nmax)
+{
+	long orange = omax - omin, nrange = nmax - nmin;
+	
+	if (orange == 0)
+		return 0;
+	return DIV_ROUND_CLOSEST(nrange * (val - omin), orange) + nmin;
+}
+
+/* convert from alsa native to oss values (0-100) */
+static long snd_mixer_oss_conv1(long val, long min, long max, int *old)
+{
+	if (val == snd_mixer_oss_conv(*old, 0, 100, min, max))
+		return *old;
+	return snd_mixer_oss_conv(val, min, max, 0, 100);
+}
+
+/* convert from oss to alsa native values */
+static long snd_mixer_oss_conv2(long val, long min, long max)
+{
+	return snd_mixer_oss_conv(val, 0, 100, min, max);
+}
+
+#if 0
+static void snd_mixer_oss_recsrce_set(struct snd_card *card, int slot)
+{
+	struct snd_mixer_oss *mixer = card->mixer_oss;
+	if (mixer)
+		mixer->mask_recsrc |= 1 << slot;
+}
+
+static int snd_mixer_oss_recsrce_get(struct snd_card *card, int slot)
+{
+	struct snd_mixer_oss *mixer = card->mixer_oss;
+	if (mixer && (mixer->mask_recsrc & (1 << slot)))
+		return 1;
+	return 0;
+}
+#endif
+
+#define SNDRV_MIXER_OSS_SIGNATURE		0x65999250
+
+#define SNDRV_MIXER_OSS_ITEM_GLOBAL	0
+#define SNDRV_MIXER_OSS_ITEM_GSWITCH	1
+#define SNDRV_MIXER_OSS_ITEM_GROUTE	2
+#define SNDRV_MIXER_OSS_ITEM_GVOLUME	3
+#define SNDRV_MIXER_OSS_ITEM_PSWITCH	4
+#define SNDRV_MIXER_OSS_ITEM_PROUTE	5
+#define SNDRV_MIXER_OSS_ITEM_PVOLUME	6
+#define SNDRV_MIXER_OSS_ITEM_CSWITCH	7
+#define SNDRV_MIXER_OSS_ITEM_CROUTE	8
+#define SNDRV_MIXER_OSS_ITEM_CVOLUME	9
+#define SNDRV_MIXER_OSS_ITEM_CAPTURE	10
+
+#define SNDRV_MIXER_OSS_ITEM_COUNT	11
+
+#define SNDRV_MIXER_OSS_PRESENT_GLOBAL	(1<<0)
+#define SNDRV_MIXER_OSS_PRESENT_GSWITCH	(1<<1)
+#define SNDRV_MIXER_OSS_PRESENT_GROUTE	(1<<2)
+#define SNDRV_MIXER_OSS_PRESENT_GVOLUME	(1<<3)
+#define SNDRV_MIXER_OSS_PRESENT_PSWITCH	(1<<4)
+#define SNDRV_MIXER_OSS_PRESENT_PROUTE	(1<<5)
+#define SNDRV_MIXER_OSS_PRESENT_PVOLUME	(1<<6)
+#define SNDRV_MIXER_OSS_PRESENT_CSWITCH	(1<<7)
+#define SNDRV_MIXER_OSS_PRESENT_CROUTE	(1<<8)
+#define SNDRV_MIXER_OSS_PRESENT_CVOLUME	(1<<9)
+#define SNDRV_MIXER_OSS_PRESENT_CAPTURE	(1<<10)
+
+struct slot {
+	unsigned int signature;
+	unsigned int present;
+	unsigned int channels;
+	unsigned int numid[SNDRV_MIXER_OSS_ITEM_COUNT];
+	unsigned int capture_item;
+	const struct snd_mixer_oss_assign_table *assigned;
+	unsigned int allocated: 1;
+};
+
+#define ID_UNKNOWN	((unsigned int)-1)
+
+static struct snd_kcontrol *snd_mixer_oss_test_id(struct snd_mixer_oss *mixer, const char *name, int index)
+{
+	struct snd_card *card = mixer->card;
+	struct snd_ctl_elem_id id;
+	
+	memset(&id, 0, sizeof(id));
+	id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+	strscpy(id.name, name, sizeof(id.name));
+	id.index = index;
+	return snd_ctl_find_id_locked(card, &id);
+}
+
+static void snd_mixer_oss_get_volume1_vol(struct snd_mixer_oss_file *fmixer,
+					  struct snd_mixer_oss_slot *pslot,
+					  unsigned int numid,
+					  int *left, int *right)
+{
+	struct snd_ctl_elem_info *uinfo;
+	struct snd_ctl_elem_value *uctl;
+	struct snd_kcontrol *kctl;
+	struct snd_card *card = fmixer->card;
+
+	if (numid == ID_UNKNOWN)
+		return;
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_numid_locked(card, numid);
+	if (!kctl) {
+		up_read(&card->controls_rwsem);
+		return;
+	}
+	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (uinfo == NULL || uctl == NULL)
+		goto __unalloc;
+	if (kctl->info(kctl, uinfo))
+		goto __unalloc;
+	if (kctl->get(kctl, uctl))
+		goto __unalloc;
+	if (uinfo->type == SNDRV_CTL_ELEM_TYPE_BOOLEAN &&
+	    uinfo->value.integer.min == 0 && uinfo->value.integer.max == 1)
+		goto __unalloc;
+	*left = snd_mixer_oss_conv1(uctl->value.integer.value[0], uinfo->value.integer.min, uinfo->value.integer.max, &pslot->volume[0]);
+	if (uinfo->count > 1)
+		*right = snd_mixer_oss_conv1(uctl->value.integer.value[1], uinfo->value.integer.min, uinfo->value.integer.max, &pslot->volume[1]);
+      __unalloc:
+	up_read(&card->controls_rwsem);
+      	kfree(uctl);
+      	kfree(uinfo);
+}
+
+static void snd_mixer_oss_get_volume1_sw(struct snd_mixer_oss_file *fmixer,
+					 struct snd_mixer_oss_slot *pslot,
+					 unsigned int numid,
+					 int *left, int *right,
+					 int route)
+{
+	struct snd_ctl_elem_info *uinfo;
+	struct snd_ctl_elem_value *uctl;
+	struct snd_kcontrol *kctl;
+	struct snd_card *card = fmixer->card;
+
+	if (numid == ID_UNKNOWN)
+		return;
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_numid_locked(card, numid);
+	if (!kctl) {
+		up_read(&card->controls_rwsem);
+		return;
+	}
+	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (uinfo == NULL || uctl == NULL)
+		goto __unalloc;
+	if (kctl->info(kctl, uinfo))
+		goto __unalloc;
+	if (kctl->get(kctl, uctl))
+		goto __unalloc;
+	if (!uctl->value.integer.value[0]) {
+		*left = 0;
+		if (uinfo->count == 1)
+			*right = 0;
+	}
+	if (uinfo->count > 1 && !uctl->value.integer.value[route ? 3 : 1])
+		*right = 0;
+      __unalloc:
+	up_read(&card->controls_rwsem);
+      	kfree(uctl);
+	kfree(uinfo);
+}
+
+static int snd_mixer_oss_get_volume1(struct snd_mixer_oss_file *fmixer,
+				     struct snd_mixer_oss_slot *pslot,
+				     int *left, int *right)
+{
+	struct slot *slot = pslot->private_data;
+	
+	*left = *right = 100;
+	if (slot->present & SNDRV_MIXER_OSS_PRESENT_PVOLUME) {
+		snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PVOLUME], left, right);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GVOLUME) {
+		snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GVOLUME], left, right);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GLOBAL) {
+		snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GLOBAL], left, right);
+	}
+	if (slot->present & SNDRV_MIXER_OSS_PRESENT_PSWITCH) {
+		snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PSWITCH], left, right, 0);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GSWITCH) {
+		snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GSWITCH], left, right, 0);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_PROUTE) {
+		snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PROUTE], left, right, 1);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE) {
+		snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
+	}
+	return 0;
+}
+
+static void snd_mixer_oss_put_volume1_vol(struct snd_mixer_oss_file *fmixer,
+					  struct snd_mixer_oss_slot *pslot,
+					  unsigned int numid,
+					  int left, int right)
+{
+	struct snd_ctl_elem_info *uinfo;
+	struct snd_ctl_elem_value *uctl;
+	struct snd_kcontrol *kctl;
+	struct snd_card *card = fmixer->card;
+	int res;
+
+	if (numid == ID_UNKNOWN)
+		return;
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_numid_locked(card, numid);
+	if (!kctl) {
+		up_read(&card->controls_rwsem);
+		return;
+	}
+	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (uinfo == NULL || uctl == NULL)
+		goto __unalloc;
+	if (kctl->info(kctl, uinfo))
+		goto __unalloc;
+	if (uinfo->type == SNDRV_CTL_ELEM_TYPE_BOOLEAN &&
+	    uinfo->value.integer.min == 0 && uinfo->value.integer.max == 1)
+		goto __unalloc;
+	uctl->value.integer.value[0] = snd_mixer_oss_conv2(left, uinfo->value.integer.min, uinfo->value.integer.max);
+	if (uinfo->count > 1)
+		uctl->value.integer.value[1] = snd_mixer_oss_conv2(right, uinfo->value.integer.min, uinfo->value.integer.max);
+	res = kctl->put(kctl, uctl);
+	if (res < 0)
+		goto __unalloc;
+	if (res > 0)
+		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
+      __unalloc:
+	up_read(&card->controls_rwsem);
+      	kfree(uctl);
+	kfree(uinfo);
+}
+
+static void snd_mixer_oss_put_volume1_sw(struct snd_mixer_oss_file *fmixer,
+					 struct snd_mixer_oss_slot *pslot,
+					 unsigned int numid,
+					 int left, int right,
+					 int route)
+{
+	struct snd_ctl_elem_info *uinfo;
+	struct snd_ctl_elem_value *uctl;
+	struct snd_kcontrol *kctl;
+	struct snd_card *card = fmixer->card;
+	int res;
+
+	if (numid == ID_UNKNOWN)
+		return;
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_numid_locked(card, numid);
+	if (!kctl) {
+		up_read(&card->controls_rwsem);
+		return;
+	}
+	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (uinfo == NULL || uctl == NULL)
+		goto __unalloc;
+	if (kctl->info(kctl, uinfo))
+		goto __unalloc;
+	if (uinfo->count > 1) {
+		uctl->value.integer.value[0] = left > 0 ? 1 : 0;
+		uctl->value.integer.value[route ? 3 : 1] = right > 0 ? 1 : 0;
+		if (route) {
+			uctl->value.integer.value[1] =
+			uctl->value.integer.value[2] = 0;
+		}
+	} else {
+		uctl->value.integer.value[0] = (left > 0 || right > 0) ? 1 : 0;
+	}
+	res = kctl->put(kctl, uctl);
+	if (res < 0)
+		goto __unalloc;
+	if (res > 0)
+		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
+      __unalloc:
+	up_read(&card->controls_rwsem);
+      	kfree(uctl);
+	kfree(uinfo);
+}
+
+static int snd_mixer_oss_put_volume1(struct snd_mixer_oss_file *fmixer,
+				     struct snd_mixer_oss_slot *pslot,
+				     int left, int right)
+{
+	struct slot *slot = pslot->private_data;
+	
+	if (slot->present & SNDRV_MIXER_OSS_PRESENT_PVOLUME) {
+		snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PVOLUME], left, right);
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_CVOLUME)
+			snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CVOLUME], left, right);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CVOLUME) {
+		snd_mixer_oss_put_volume1_vol(fmixer, pslot,
+			slot->numid[SNDRV_MIXER_OSS_ITEM_CVOLUME], left, right);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GVOLUME) {
+		snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GVOLUME], left, right);
+	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GLOBAL) {
+		snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GLOBAL], left, right);
+	}
+	if (left || right) {
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_PSWITCH)
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PSWITCH], left, right, 0);
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_CSWITCH)
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], left, right, 0);
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_GSWITCH)
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GSWITCH], left, right, 0);
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_PROUTE)
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PROUTE], left, right, 1);
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_CROUTE)
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], left, right, 1);
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE)
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
+	} else {
+		if (slot->present & SNDRV_MIXER_OSS_PRESENT_PSWITCH) {
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PSWITCH], left, right, 0);
+		} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CSWITCH) {
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], left, right, 0);
+		} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GSWITCH) {
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GSWITCH], left, right, 0);
+		} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_PROUTE) {
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_PROUTE], left, right, 1);
+		} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CROUTE) {
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], left, right, 1);
+		} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE) {
+			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
+		}
+	}
+	return 0;
+}
+
+static int snd_mixer_oss_get_recsrc1_sw(struct snd_mixer_oss_file *fmixer,
+					struct snd_mixer_oss_slot *pslot,
+					int *active)
+{
+	struct slot *slot = pslot->private_data;
+	int left, right;
+	
+	left = right = 1;
+	snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], &left, &right, 0);
+	*active = (left || right) ? 1 : 0;
+	return 0;
+}
+
+static int snd_mixer_oss_get_recsrc1_route(struct snd_mixer_oss_file *fmixer,
+					   struct snd_mixer_oss_slot *pslot,
+					   int *active)
+{
+	struct slot *slot = pslot->private_data;
+	int left, right;
+	
+	left = right = 1;
+	snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], &left, &right, 1);
+	*active = (left || right) ? 1 : 0;
+	return 0;
+}
+
+static int snd_mixer_oss_put_recsrc1_sw(struct snd_mixer_oss_file *fmixer,
+					struct snd_mixer_oss_slot *pslot,
+					int active)
+{
+	struct slot *slot = pslot->private_data;
+	
+	snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CSWITCH], active, active, 0);
+	return 0;
+}
+
+static int snd_mixer_oss_put_recsrc1_route(struct snd_mixer_oss_file *fmixer,
+					   struct snd_mixer_oss_slot *pslot,
+					   int active)
+{
+	struct slot *slot = pslot->private_data;
+	
+	snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->numid[SNDRV_MIXER_OSS_ITEM_CROUTE], active, active, 1);
+	return 0;
+}
+
+static int snd_mixer_oss_get_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned int *active_index)
+{
+	struct snd_card *card = fmixer->card;
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_kcontrol *kctl;
+	struct snd_mixer_oss_slot *pslot;
+	struct slot *slot;
+	struct snd_ctl_elem_info *uinfo;
+	struct snd_ctl_elem_value *uctl;
+	int err, idx;
+	
+	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (uinfo == NULL || uctl == NULL) {
+		err = -ENOMEM;
+		goto __free_only;
+	}
+	down_read(&card->controls_rwsem);
+	kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
+	if (! kctl) {
+		err = -ENOENT;
+		goto __unlock;
+	}
+	err = kctl->info(kctl, uinfo);
+	if (err < 0)
+		goto __unlock;
+	err = kctl->get(kctl, uctl);
+	if (err < 0)
+		goto __unlock;
+	for (idx = 0; idx < 32; idx++) {
+		if (!(mixer->mask_recsrc & (1 << idx)))
+			continue;
+		pslot = &mixer->slots[idx];
+		slot = pslot->private_data;
+		if (slot->signature != SNDRV_MIXER_OSS_SIGNATURE)
+			continue;
+		if (!(slot->present & SNDRV_MIXER_OSS_PRESENT_CAPTURE))
+			continue;
+		if (slot->capture_item == uctl->value.enumerated.item[0]) {
+			*active_index = idx;
+			break;
+		}
+	}
+	err = 0;
+      __unlock:
+     	up_read(&card->controls_rwsem);
+      __free_only:
+      	kfree(uctl);
+      	kfree(uinfo);
+      	return err;
+}
+
+static int snd_mixer_oss_put_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned int active_index)
+{
+	struct snd_card *card = fmixer->card;
+	struct snd_mixer_oss *mixer = fmixer->mixer;
+	struct snd_kcontrol *kctl;
+	struct snd_mixer_oss_slot *pslot;
+	struct slot *slot = NULL;
+	struct snd_ctl_elem_info *uinfo;
+	struct snd_ctl_elem_value *uctl;
+	int err;
+	unsigned int idx;
+
+	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (uinfo == NULL || uctl == NULL) {
+		err = -ENOMEM;
+		goto __free_only;
+	}
+	down_read(&card->controls_rwsem);
+	kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
+	if (! kctl) {
+		err = -ENOENT;
+		goto __unlock;
+	}
+	err = kctl->info(kctl, uinfo);
+	if (err < 0)
+		goto __unlock;
+	for (idx = 0; idx < 32; idx++) {
+		if (!(mixer->mask_recsrc & (1 << idx)))
+			continue;
+		pslot = &mixer->slots[idx];
+		slot = pslot->private_data;
+		if (slot->signature != SNDRV_MIXER_OSS_SIGNATURE)
+			continue;
+		if (!(slot->present & SNDRV_MIXER_OSS_PRESENT_CAPTURE))
+			continue;
+		if (idx == active_index)
+			break;
+		slot = NULL;
+	}
+	if (! slot)
+		goto __unlock;
+	for (idx = 0; idx < uinfo->count; idx++)
+		uctl->value.enumerated.item[idx] = slot->capture_item;
+	err = kctl->put(kctl, uctl);
+	if (err > 0)
+		snd_ctl_notify(fmixer->card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
+	err = 0;
+      __unlock:
+	up_read(&card->controls_rwsem);
+      __free_only:
+	kfree(uctl);
+	kfree(uinfo);
+	return err;
+}
+
+struct snd_mixer_oss_assign_table {
+	int oss_id;
+	const char *name;
+	int index;
+};
+
+static int snd_mixer_oss_build_test(struct snd_mixer_oss *mixer, struct slot *slot, const char *name, int index, int item)
+{
+	struct snd_ctl_elem_info *info;
+	struct snd_kcontrol *kcontrol;
+	struct snd_card *card = mixer->card;
+	int err;
+
+	down_read(&card->controls_rwsem);
+	kcontrol = snd_mixer_oss_test_id(mixer, name, index);
+	if (kcontrol == NULL) {
+		up_read(&card->controls_rwsem);
+		return 0;
+	}
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (! info) {
+		up_read(&card->controls_rwsem);
+		return -ENOMEM;
+	}
+	err = kcontrol->info(kcontrol, info);
+	if (err < 0) {
+		up_read(&card->controls_rwsem);
+		kfree(info);
+		return err;
+	}
+	slot->numid[item] = kcontrol->id.numid;
+	up_read(&card->controls_rwsem);
+	if (info->count > slot->channels)
+		slot->channels = info->count;
+	slot->present |= 1 << item;
+	kfree(info);
+	return 0;
+}
+
+static void snd_mixer_oss_slot_free(struct snd_mixer_oss_slot *chn)
+{
+	struct slot *p = chn->private_data;
+	if (p) {
+		if (p->allocated && p->assigned) {
+			kfree_const(p->assigned->name);
+			kfree_const(p->assigned);
+		}
+		kfree(p);
+	}
+}
+
+static void mixer_slot_clear(struct snd_mixer_oss_slot *rslot)
+{
+	int idx = rslot->number; /* remember this */
+	if (rslot->private_free)
+		rslot->private_free(rslot);
+	memset(rslot, 0, sizeof(*rslot));
+	rslot->number = idx;
+}
+
+/* In a separate function to keep gcc 3.2 happy - do NOT merge this in
+   snd_mixer_oss_build_input! */
+static int snd_mixer_oss_build_test_all(struct snd_mixer_oss *mixer,
+					const struct snd_mixer_oss_assign_table *ptr,
+					struct slot *slot)
+{
+	char str[64];
+	int err;
+
+	err = snd_mixer_oss_build_test(mixer, slot, ptr->name, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_GLOBAL);
+	if (err)
+		return err;
+	sprintf(str, "%s Switch", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_GSWITCH);
+	if (err)
+		return err;
+	sprintf(str, "%s Route", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_GROUTE);
+	if (err)
+		return err;
+	sprintf(str, "%s Volume", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_GVOLUME);
+	if (err)
+		return err;
+	sprintf(str, "%s Playback Switch", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_PSWITCH);
+	if (err)
+		return err;
+	sprintf(str, "%s Playback Route", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_PROUTE);
+	if (err)
+		return err;
+	sprintf(str, "%s Playback Volume", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_PVOLUME);
+	if (err)
+		return err;
+	sprintf(str, "%s Capture Switch", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_CSWITCH);
+	if (err)
+		return err;
+	sprintf(str, "%s Capture Route", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_CROUTE);
+	if (err)
+		return err;
+	sprintf(str, "%s Capture Volume", ptr->name);
+	err = snd_mixer_oss_build_test(mixer, slot, str, ptr->index,
+				       SNDRV_MIXER_OSS_ITEM_CVOLUME);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+/*
+ * build an OSS mixer element.
+ * ptr_allocated means the entry is dynamically allocated (change via proc file).
+ * when replace_old = 1, the old entry is replaced with the new one.
+ */
+static int snd_mixer_oss_build_input(struct snd_mixer_oss *mixer,
+				     const struct snd_mixer_oss_assign_table *ptr,
+				     int ptr_allocated, int replace_old)
+{
+	struct slot slot;
+	struct slot *pslot;
+	struct snd_kcontrol *kctl;
+	struct snd_mixer_oss_slot *rslot;
+	char str[64];	
+	
+	/* check if already assigned */
+	if (mixer->slots[ptr->oss_id].get_volume && ! replace_old)
+		return 0;
+
+	memset(&slot, 0, sizeof(slot));
+	memset(slot.numid, 0xff, sizeof(slot.numid)); /* ID_UNKNOWN */
+	if (snd_mixer_oss_build_test_all(mixer, ptr, &slot))
+		return 0;
+	down_read(&mixer->card->controls_rwsem);
+	kctl = NULL;
+	if (!ptr->index)
+		kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
+	if (kctl) {
+		struct snd_ctl_elem_info *uinfo;
+
+		uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
+		if (! uinfo) {
+			up_read(&mixer->card->controls_rwsem);
+			return -ENOMEM;
+		}
+			
+		if (kctl->info(kctl, uinfo)) {
+			up_read(&mixer->card->controls_rwsem);
+			kfree(uinfo);
+			return 0;
+		}
+		strcpy(str, ptr->name);
+		if (!strcmp(str, "Master"))
+			strcpy(str, "Mix");
+		if (!strcmp(str, "Master Mono"))
+			strcpy(str, "Mix Mono");
+		slot.capture_item = 0;
+		if (!strcmp(uinfo->value.enumerated.name, str)) {
+			slot.present |= SNDRV_MIXER_OSS_PRESENT_CAPTURE;
+		} else {
+			for (slot.capture_item = 1; slot.capture_item < uinfo->value.enumerated.items; slot.capture_item++) {
+				uinfo->value.enumerated.item = slot.capture_item;
+				if (kctl->info(kctl, uinfo)) {
+					up_read(&mixer->card->controls_rwsem);
+					kfree(uinfo);
+					return 0;
+				}
+				if (!strcmp(uinfo->value.enumerated.name, str)) {
+					slot.present |= SNDRV_MIXER_OSS_PRESENT_CAPTURE;
+					break;
+				}
+			}
+		}
+		kfree(uinfo);
+	}
+	up_read(&mixer->card->controls_rwsem);
+	if (slot.present != 0) {
+		pslot = kmalloc(sizeof(slot), GFP_KERNEL);
+		if (! pslot)
+			return -ENOMEM;
+		*pslot = slot;
+		pslot->signature = SNDRV_MIXER_OSS_SIGNATURE;
+		pslot->assigned = ptr;
+		pslot->allocated = ptr_allocated;
+		rslot = &mixer->slots[ptr->oss_id];
+		mixer_slot_clear(rslot);
+		rslot->stereo = slot.channels > 1 ? 1 : 0;
+		rslot->get_volume = snd_mixer_oss_get_volume1;
+		rslot->put_volume = snd_mixer_oss_put_volume1;
+		/* note: ES18xx have both Capture Source and XX Capture Volume !!! */
+		if (slot.present & SNDRV_MIXER_OSS_PRESENT_CSWITCH) {
+			rslot->get_recsrc = snd_mixer_oss_get_recsrc1_sw;
+			rslot->put_recsrc = snd_mixer_oss_put_recsrc1_sw;
+		} else if (slot.present & SNDRV_MIXER_OSS_PRESENT_CROUTE) {
+			rslot->get_recsrc = snd_mixer_oss_get_recsrc1_route;
+			rslot->put_recsrc = snd_mixer_oss_put_recsrc1_route;
+		} else if (slot.present & SNDRV_MIXER_OSS_PRESENT_CAPTURE) {
+			mixer->mask_recsrc |= 1 << ptr->oss_id;
+		}
+		rslot->private_data = pslot;
+		rslot->private_free = snd_mixer_oss_slot_free;
+		return 1;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ */
+#define MIXER_VOL(name) [SOUND_MIXER_##name] = #name
+static const char * const oss_mixer_names[SNDRV_OSS_MAX_MIXERS] = {
+	MIXER_VOL(VOLUME),
+	MIXER_VOL(BASS),
+	MIXER_VOL(TREBLE),
+	MIXER_VOL(SYNTH),
+	MIXER_VOL(PCM),
+	MIXER_VOL(SPEAKER),
+	MIXER_VOL(LINE),
+	MIXER_VOL(MIC),
+	MIXER_VOL(CD),
+	MIXER_VOL(IMIX),
+	MIXER_VOL(ALTPCM),
+	MIXER_VOL(RECLEV),
+	MIXER_VOL(IGAIN),
+	MIXER_VOL(OGAIN),
+	MIXER_VOL(LINE1),
+	MIXER_VOL(LINE2),
+	MIXER_VOL(LINE3),
+	MIXER_VOL(DIGITAL1),
+	MIXER_VOL(DIGITAL2),
+	MIXER_VOL(DIGITAL3),
+	MIXER_VOL(PHONEIN),
+	MIXER_VOL(PHONEOUT),
+	MIXER_VOL(VIDEO),
+	MIXER_VOL(RADIO),
+	MIXER_VOL(MONITOR),
+};
+	
+/*
+ *  /proc interface
+ */
+
+static void snd_mixer_oss_proc_read(struct snd_info_entry *entry,
+				    struct snd_info_buffer *buffer)
+{
+	struct snd_mixer_oss *mixer = entry->private_data;
+	int i;
+
+	mutex_lock(&mixer->reg_mutex);
+	for (i = 0; i < SNDRV_OSS_MAX_MIXERS; i++) {
+		struct slot *p;
+
+		if (! oss_mixer_names[i])
+			continue;
+		p = (struct slot *)mixer->slots[i].private_data;
+		snd_iprintf(buffer, "%s ", oss_mixer_names[i]);
+		if (p && p->assigned)
+			snd_iprintf(buffer, "\"%s\" %d\n",
+				    p->assigned->name,
+				    p->assigned->index);
+		else
+			snd_iprintf(buffer, "\"\" 0\n");
+	}
+	mutex_unlock(&mixer->reg_mutex);
+}
+
+static void snd_mixer_oss_proc_write(struct snd_info_entry *entry,
+				     struct snd_info_buffer *buffer)
+{
+	struct snd_mixer_oss *mixer = entry->private_data;
+	char line[128], str[32], idxstr[16];
+	const char *cptr;
+	unsigned int idx;
+	int ch;
+	struct snd_mixer_oss_assign_table *tbl;
+	struct slot *slot;
+
+	while (!snd_info_get_line(buffer, line, sizeof(line))) {
+		cptr = snd_info_get_str(str, line, sizeof(str));
+		for (ch = 0; ch < SNDRV_OSS_MAX_MIXERS; ch++)
+			if (oss_mixer_names[ch] && strcmp(oss_mixer_names[ch], str) == 0)
+				break;
+		if (ch >= SNDRV_OSS_MAX_MIXERS) {
+			pr_err("ALSA: mixer_oss: invalid OSS volume '%s'\n",
+			       str);
+			continue;
+		}
+		cptr = snd_info_get_str(str, cptr, sizeof(str));
+		if (! *str) {
+			/* remove the entry */
+			mutex_lock(&mixer->reg_mutex);
+			mixer_slot_clear(&mixer->slots[ch]);
+			mutex_unlock(&mixer->reg_mutex);
+			continue;
+		}
+		snd_info_get_str(idxstr, cptr, sizeof(idxstr));
+		idx = simple_strtoul(idxstr, NULL, 10);
+		if (idx >= 0x4000) { /* too big */
+			pr_err("ALSA: mixer_oss: invalid index %d\n", idx);
+			continue;
+		}
+		mutex_lock(&mixer->reg_mutex);
+		slot = (struct slot *)mixer->slots[ch].private_data;
+		if (slot && slot->assigned &&
+		    slot->assigned->index == idx && ! strcmp(slot->assigned->name, str))
+			/* not changed */
+			goto __unlock;
+		tbl = kmalloc(sizeof(*tbl), GFP_KERNEL);
+		if (!tbl)
+			goto __unlock;
+		tbl->oss_id = ch;
+		tbl->name = kstrdup(str, GFP_KERNEL);
+		if (! tbl->name) {
+			kfree(tbl);
+			goto __unlock;
+		}
+		tbl->index = idx;
+		if (snd_mixer_oss_build_input(mixer, tbl, 1, 1) <= 0) {
+			kfree(tbl->name);
+			kfree(tbl);
+		}
+	__unlock:
+		mutex_unlock(&mixer->reg_mutex);
+	}
+}
+
+static void snd_mixer_oss_proc_init(struct snd_mixer_oss *mixer)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(mixer->card, "oss_mixer",
+					   mixer->card->proc_root);
+	if (! entry)
+		return;
+	entry->content = SNDRV_INFO_CONTENT_TEXT;
+	entry->mode = S_IFREG | 0644;
+	entry->c.text.read = snd_mixer_oss_proc_read;
+	entry->c.text.write = snd_mixer_oss_proc_write;
+	entry->private_data = mixer;
+	if (snd_info_register(entry) < 0) {
+		snd_info_free_entry(entry);
+		entry = NULL;
+	}
+	mixer->proc_entry = entry;
+}
+
+static void snd_mixer_oss_proc_done(struct snd_mixer_oss *mixer)
+{
+	snd_info_free_entry(mixer->proc_entry);
+	mixer->proc_entry = NULL;
+}
+#else /* !CONFIG_SND_PROC_FS */
+#define snd_mixer_oss_proc_init(mix)
+#define snd_mixer_oss_proc_done(mix)
+#endif /* CONFIG_SND_PROC_FS */
+
+static void snd_mixer_oss_build(struct snd_mixer_oss *mixer)
+{
+	static const struct snd_mixer_oss_assign_table table[] = {
+		{ SOUND_MIXER_VOLUME, 	"Master",		0 },
+		{ SOUND_MIXER_VOLUME, 	"Front",		0 }, /* fallback */
+		{ SOUND_MIXER_BASS,	"Tone Control - Bass",	0 },
+		{ SOUND_MIXER_TREBLE,	"Tone Control - Treble", 0 },
+		{ SOUND_MIXER_SYNTH,	"Synth",		0 },
+		{ SOUND_MIXER_SYNTH,	"FM",			0 }, /* fallback */
+		{ SOUND_MIXER_SYNTH,	"Music",		0 }, /* fallback */
+		{ SOUND_MIXER_PCM,	"PCM",			0 },
+		{ SOUND_MIXER_SPEAKER,	"Beep", 		0 },
+		{ SOUND_MIXER_SPEAKER,	"PC Speaker", 		0 }, /* fallback */
+		{ SOUND_MIXER_SPEAKER,	"Speaker", 		0 }, /* fallback */
+		{ SOUND_MIXER_LINE,	"Line", 		0 },
+		{ SOUND_MIXER_MIC,	"Mic", 			0 },
+		{ SOUND_MIXER_CD,	"CD", 			0 },
+		{ SOUND_MIXER_IMIX,	"Monitor Mix", 		0 },
+		{ SOUND_MIXER_ALTPCM,	"PCM",			1 },
+		{ SOUND_MIXER_ALTPCM,	"Headphone",		0 }, /* fallback */
+		{ SOUND_MIXER_ALTPCM,	"Wave",			0 }, /* fallback */
+		{ SOUND_MIXER_RECLEV,	"-- nothing --",	0 },
+		{ SOUND_MIXER_IGAIN,	"Capture",		0 },
+		{ SOUND_MIXER_OGAIN,	"Playback",		0 },
+		{ SOUND_MIXER_LINE1,	"Aux",			0 },
+		{ SOUND_MIXER_LINE2,	"Aux",			1 },
+		{ SOUND_MIXER_LINE3,	"Aux",			2 },
+		{ SOUND_MIXER_DIGITAL1,	"Digital",		0 },
+		{ SOUND_MIXER_DIGITAL1,	"IEC958",		0 }, /* fallback */
+		{ SOUND_MIXER_DIGITAL1,	"IEC958 Optical",	0 }, /* fallback */
+		{ SOUND_MIXER_DIGITAL1,	"IEC958 Coaxial",	0 }, /* fallback */
+		{ SOUND_MIXER_DIGITAL2,	"Digital",		1 },
+		{ SOUND_MIXER_DIGITAL3,	"Digital",		2 },
+		{ SOUND_MIXER_PHONEIN,	"Phone",		0 },
+		{ SOUND_MIXER_PHONEOUT,	"Master Mono",		0 },
+		{ SOUND_MIXER_PHONEOUT,	"Speaker",		0 }, /*fallback*/
+		{ SOUND_MIXER_PHONEOUT,	"Mono",			0 }, /*fallback*/
+		{ SOUND_MIXER_PHONEOUT,	"Phone",		0 }, /* fallback */
+		{ SOUND_MIXER_VIDEO,	"Video",		0 },
+		{ SOUND_MIXER_RADIO,	"Radio",		0 },
+		{ SOUND_MIXER_MONITOR,	"Monitor",		0 }
+	};
+	unsigned int idx;
+	
+	for (idx = 0; idx < ARRAY_SIZE(table); idx++)
+		snd_mixer_oss_build_input(mixer, &table[idx], 0, 0);
+	if (mixer->mask_recsrc) {
+		mixer->get_recsrc = snd_mixer_oss_get_recsrc2;
+		mixer->put_recsrc = snd_mixer_oss_put_recsrc2;
+	}
+}
+
+/*
+ *
+ */
+
+static int snd_mixer_oss_free1(void *private)
+{
+	struct snd_mixer_oss *mixer = private;
+	struct snd_card *card;
+	int idx;
+ 
+	if (!mixer)
+		return 0;
+	card = mixer->card;
+	if (snd_BUG_ON(mixer != card->mixer_oss))
+		return -ENXIO;
+	card->mixer_oss = NULL;
+	for (idx = 0; idx < SNDRV_OSS_MAX_MIXERS; idx++) {
+		struct snd_mixer_oss_slot *chn = &mixer->slots[idx];
+		if (chn->private_free)
+			chn->private_free(chn);
+	}
+	kfree(mixer);
+	return 0;
+}
+
+static int snd_mixer_oss_notify_handler(struct snd_card *card, int cmd)
+{
+	struct snd_mixer_oss *mixer;
+
+	if (cmd == SND_MIXER_OSS_NOTIFY_REGISTER) {
+		int idx, err;
+
+		mixer = kcalloc(2, sizeof(*mixer), GFP_KERNEL);
+		if (mixer == NULL)
+			return -ENOMEM;
+		mutex_init(&mixer->reg_mutex);
+		err = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIXER,
+					      card, 0,
+					      &snd_mixer_oss_f_ops, card);
+		if (err < 0) {
+			dev_err(card->dev,
+				"unable to register OSS mixer device %i:%i\n",
+				card->number, 0);
+			kfree(mixer);
+			return err;
+		}
+		mixer->oss_dev_alloc = 1;
+		mixer->card = card;
+		if (*card->mixername)
+			strscpy(mixer->name, card->mixername, sizeof(mixer->name));
+		else
+			snprintf(mixer->name, sizeof(mixer->name),
+				 "mixer%i", card->number);
+#ifdef SNDRV_OSS_INFO_DEV_MIXERS
+		snd_oss_info_register(SNDRV_OSS_INFO_DEV_MIXERS,
+				      card->number,
+				      mixer->name);
+#endif
+		for (idx = 0; idx < SNDRV_OSS_MAX_MIXERS; idx++)
+			mixer->slots[idx].number = idx;
+		card->mixer_oss = mixer;
+		snd_mixer_oss_build(mixer);
+		snd_mixer_oss_proc_init(mixer);
+	} else {
+		mixer = card->mixer_oss;
+		if (mixer == NULL)
+			return 0;
+		if (mixer->oss_dev_alloc) {
+#ifdef SNDRV_OSS_INFO_DEV_MIXERS
+			snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIXERS, mixer->card->number);
+#endif
+			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIXER, mixer->card, 0);
+			mixer->oss_dev_alloc = 0;
+		}
+		if (cmd == SND_MIXER_OSS_NOTIFY_DISCONNECT)
+			return 0;
+		snd_mixer_oss_proc_done(mixer);
+		return snd_mixer_oss_free1(mixer);
+	}
+	return 0;
+}
+
+static int __init alsa_mixer_oss_init(void)
+{
+	struct snd_card *card;
+	int idx;
+	
+	snd_mixer_oss_notify_callback = snd_mixer_oss_notify_handler;
+	for (idx = 0; idx < SNDRV_CARDS; idx++) {
+		card = snd_card_ref(idx);
+		if (card) {
+			snd_mixer_oss_notify_handler(card, SND_MIXER_OSS_NOTIFY_REGISTER);
+			snd_card_unref(card);
+		}
+	}
+	return 0;
+}
+
+static void __exit alsa_mixer_oss_exit(void)
+{
+	struct snd_card *card;
+	int idx;
+
+	snd_mixer_oss_notify_callback = NULL;
+	for (idx = 0; idx < SNDRV_CARDS; idx++) {
+		card = snd_card_ref(idx);
+		if (card) {
+			snd_mixer_oss_notify_handler(card, SND_MIXER_OSS_NOTIFY_FREE);
+			snd_card_unref(card);
+		}
+	}
+}
+
+module_init(alsa_mixer_oss_init)
+module_exit(alsa_mixer_oss_exit)
diff --git a/sound/core/oss/mulaw.c b/sound/core/oss/mulaw.c
new file mode 100644
index 0000000000..fe27034f28
--- /dev/null
+++ b/sound/core/oss/mulaw.c
@@ -0,0 +1,346 @@
+/*
+ *  Mu-Law conversion Plug-In Interface
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+ *                        Uros Bizjak <uros@kss-loka.si>
+ *
+ *  Based on reference implementation by Sun Microsystems, Inc.
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+  
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+#define	SIGN_BIT	(0x80)		/* Sign bit for a u-law byte. */
+#define	QUANT_MASK	(0xf)		/* Quantization field mask. */
+#define	NSEGS		(8)		/* Number of u-law segments. */
+#define	SEG_SHIFT	(4)		/* Left shift for segment number. */
+#define	SEG_MASK	(0x70)		/* Segment field mask. */
+
+static inline int val_seg(int val)
+{
+	int r = 0;
+	val >>= 7;
+	if (val & 0xf0) {
+		val >>= 4;
+		r += 4;
+	}
+	if (val & 0x0c) {
+		val >>= 2;
+		r += 2;
+	}
+	if (val & 0x02)
+		r += 1;
+	return r;
+}
+
+#define	BIAS		(0x84)		/* Bias for linear code. */
+
+/*
+ * linear2ulaw() - Convert a linear PCM value to u-law
+ *
+ * In order to simplify the encoding process, the original linear magnitude
+ * is biased by adding 33 which shifts the encoding range from (0 - 8158) to
+ * (33 - 8191). The result can be seen in the following encoding table:
+ *
+ *	Biased Linear Input Code	Compressed Code
+ *	------------------------	---------------
+ *	00000001wxyza			000wxyz
+ *	0000001wxyzab			001wxyz
+ *	000001wxyzabc			010wxyz
+ *	00001wxyzabcd			011wxyz
+ *	0001wxyzabcde			100wxyz
+ *	001wxyzabcdef			101wxyz
+ *	01wxyzabcdefg			110wxyz
+ *	1wxyzabcdefgh			111wxyz
+ *
+ * Each biased linear code has a leading 1 which identifies the segment
+ * number. The value of the segment number is equal to 7 minus the number
+ * of leading 0's. The quantization interval is directly available as the
+ * four bits wxyz.  * The trailing bits (a - h) are ignored.
+ *
+ * Ordinarily the complement of the resulting code word is used for
+ * transmission, and so the code word is complemented before it is returned.
+ *
+ * For further information see John C. Bellamy's Digital Telephony, 1982,
+ * John Wiley & Sons, pps 98-111 and 472-476.
+ */
+static unsigned char linear2ulaw(int pcm_val)	/* 2's complement (16-bit range) */
+{
+	int mask;
+	int seg;
+	unsigned char uval;
+
+	/* Get the sign and the magnitude of the value. */
+	if (pcm_val < 0) {
+		pcm_val = BIAS - pcm_val;
+		mask = 0x7F;
+	} else {
+		pcm_val += BIAS;
+		mask = 0xFF;
+	}
+	if (pcm_val > 0x7FFF)
+		pcm_val = 0x7FFF;
+
+	/* Convert the scaled magnitude to segment number. */
+	seg = val_seg(pcm_val);
+
+	/*
+	 * Combine the sign, segment, quantization bits;
+	 * and complement the code word.
+	 */
+	uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0xF);
+	return uval ^ mask;
+}
+
+/*
+ * ulaw2linear() - Convert a u-law value to 16-bit linear PCM
+ *
+ * First, a biased linear code is derived from the code word. An unbiased
+ * output can then be obtained by subtracting 33 from the biased code.
+ *
+ * Note that this function expects to be passed the complement of the
+ * original code word. This is in keeping with ISDN conventions.
+ */
+static int ulaw2linear(unsigned char u_val)
+{
+	int t;
+
+	/* Complement to obtain normal u-law value. */
+	u_val = ~u_val;
+
+	/*
+	 * Extract and bias the quantization bits. Then
+	 * shift up by the segment number and subtract out the bias.
+	 */
+	t = ((u_val & QUANT_MASK) << 3) + BIAS;
+	t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
+
+	return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
+}
+
+/*
+ *  Basic Mu-Law plugin
+ */
+
+typedef void (*mulaw_f)(struct snd_pcm_plugin *plugin,
+			const struct snd_pcm_plugin_channel *src_channels,
+			struct snd_pcm_plugin_channel *dst_channels,
+			snd_pcm_uframes_t frames);
+
+struct mulaw_priv {
+	mulaw_f func;
+	int cvt_endian;			/* need endian conversion? */
+	unsigned int native_ofs;	/* byte offset in native format */
+	unsigned int copy_ofs;		/* byte offset in s16 format */
+	unsigned int native_bytes;	/* byte size of the native format */
+	unsigned int copy_bytes;	/* bytes to copy per conversion */
+	u16 flip; /* MSB flip for signedness, done after endian conversion */
+};
+
+static inline void cvt_s16_to_native(struct mulaw_priv *data,
+				     unsigned char *dst, u16 sample)
+{
+	sample ^= data->flip;
+	if (data->cvt_endian)
+		sample = swab16(sample);
+	if (data->native_bytes > data->copy_bytes)
+		memset(dst, 0, data->native_bytes);
+	memcpy(dst + data->native_ofs, (char *)&sample + data->copy_ofs,
+	       data->copy_bytes);
+}
+
+static void mulaw_decode(struct snd_pcm_plugin *plugin,
+			const struct snd_pcm_plugin_channel *src_channels,
+			struct snd_pcm_plugin_channel *dst_channels,
+			snd_pcm_uframes_t frames)
+{
+	struct mulaw_priv *data = (struct mulaw_priv *)plugin->extra_data;
+	int channel;
+	int nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		snd_pcm_uframes_t frames1;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
+		dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
+		src_step = src_channels[channel].area.step / 8;
+		dst_step = dst_channels[channel].area.step / 8;
+		frames1 = frames;
+		while (frames1-- > 0) {
+			signed short sample = ulaw2linear(*src);
+			cvt_s16_to_native(data, dst, sample);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static inline signed short cvt_native_to_s16(struct mulaw_priv *data,
+					     unsigned char *src)
+{
+	u16 sample = 0;
+	memcpy((char *)&sample + data->copy_ofs, src + data->native_ofs,
+	       data->copy_bytes);
+	if (data->cvt_endian)
+		sample = swab16(sample);
+	sample ^= data->flip;
+	return (signed short)sample;
+}
+
+static void mulaw_encode(struct snd_pcm_plugin *plugin,
+			const struct snd_pcm_plugin_channel *src_channels,
+			struct snd_pcm_plugin_channel *dst_channels,
+			snd_pcm_uframes_t frames)
+{
+	struct mulaw_priv *data = (struct mulaw_priv *)plugin->extra_data;
+	int channel;
+	int nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		snd_pcm_uframes_t frames1;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
+		dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
+		src_step = src_channels[channel].area.step / 8;
+		dst_step = dst_channels[channel].area.step / 8;
+		frames1 = frames;
+		while (frames1-- > 0) {
+			signed short sample = cvt_native_to_s16(data, src);
+			*dst = linear2ulaw(sample);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static snd_pcm_sframes_t mulaw_transfer(struct snd_pcm_plugin *plugin,
+			      const struct snd_pcm_plugin_channel *src_channels,
+			      struct snd_pcm_plugin_channel *dst_channels,
+			      snd_pcm_uframes_t frames)
+{
+	struct mulaw_priv *data;
+
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+#ifdef CONFIG_SND_DEBUG
+	{
+		unsigned int channel;
+		for (channel = 0; channel < plugin->src_format.channels; channel++) {
+			if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
+				       src_channels[channel].area.step % 8))
+				return -ENXIO;
+			if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
+				       dst_channels[channel].area.step % 8))
+				return -ENXIO;
+		}
+	}
+#endif
+	if (frames > dst_channels[0].frames)
+		frames = dst_channels[0].frames;
+	data = (struct mulaw_priv *)plugin->extra_data;
+	data->func(plugin, src_channels, dst_channels, frames);
+	return frames;
+}
+
+static void init_data(struct mulaw_priv *data, snd_pcm_format_t format)
+{
+#ifdef SNDRV_LITTLE_ENDIAN
+	data->cvt_endian = snd_pcm_format_big_endian(format) > 0;
+#else
+	data->cvt_endian = snd_pcm_format_little_endian(format) > 0;
+#endif
+	if (!snd_pcm_format_signed(format))
+		data->flip = 0x8000;
+	data->native_bytes = snd_pcm_format_physical_width(format) / 8;
+	data->copy_bytes = data->native_bytes < 2 ? 1 : 2;
+	if (snd_pcm_format_little_endian(format)) {
+		data->native_ofs = data->native_bytes - data->copy_bytes;
+		data->copy_ofs = 2 - data->copy_bytes;
+	} else {
+		/* S24 in 4bytes need an 1 byte offset */
+		data->native_ofs = data->native_bytes -
+			snd_pcm_format_width(format) / 8;
+	}
+}
+
+int snd_pcm_plugin_build_mulaw(struct snd_pcm_substream *plug,
+			       struct snd_pcm_plugin_format *src_format,
+			       struct snd_pcm_plugin_format *dst_format,
+			       struct snd_pcm_plugin **r_plugin)
+{
+	int err;
+	struct mulaw_priv *data;
+	struct snd_pcm_plugin *plugin;
+	struct snd_pcm_plugin_format *format;
+	mulaw_f func;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+
+	if (snd_BUG_ON(src_format->rate != dst_format->rate))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->channels != dst_format->channels))
+		return -ENXIO;
+
+	if (dst_format->format == SNDRV_PCM_FORMAT_MU_LAW) {
+		format = src_format;
+		func = mulaw_encode;
+	}
+	else if (src_format->format == SNDRV_PCM_FORMAT_MU_LAW) {
+		format = dst_format;
+		func = mulaw_decode;
+	}
+	else {
+		snd_BUG();
+		return -EINVAL;
+	}
+	if (!snd_pcm_format_linear(format->format))
+		return -EINVAL;
+
+	err = snd_pcm_plugin_build(plug, "Mu-Law<->linear conversion",
+				   src_format, dst_format,
+				   sizeof(struct mulaw_priv), &plugin);
+	if (err < 0)
+		return err;
+	data = (struct mulaw_priv *)plugin->extra_data;
+	data->func = func;
+	init_data(data, format->format);
+	plugin->transfer = mulaw_transfer;
+	*r_plugin = plugin;
+	return 0;
+}
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
new file mode 100644
index 0000000000..728c211142
--- /dev/null
+++ b/sound/core/oss/pcm_oss.c
@@ -0,0 +1,3244 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer / OSS compatible
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#if 0
+#define PLUGIN_DEBUG
+#endif
+#if 0
+#define OSS_DEBUG
+#endif
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/time.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <linux/math64.h>
+#include <linux/string.h>
+#include <linux/compat.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include "pcm_plugin.h"
+#include <sound/info.h>
+#include <linux/soundcard.h>
+#include <sound/initval.h>
+#include <sound/mixer_oss.h>
+
+#define OSS_ALSAEMULVER		_SIOR ('M', 249, int)
+
+static int dsp_map[SNDRV_CARDS];
+static int adsp_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
+static bool nonblock_open = 1;
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
+MODULE_DESCRIPTION("PCM OSS emulation for ALSA.");
+MODULE_LICENSE("GPL");
+module_param_array(dsp_map, int, NULL, 0444);
+MODULE_PARM_DESC(dsp_map, "PCM device number assigned to 1st OSS device.");
+module_param_array(adsp_map, int, NULL, 0444);
+MODULE_PARM_DESC(adsp_map, "PCM device number assigned to 2nd OSS device.");
+module_param(nonblock_open, bool, 0644);
+MODULE_PARM_DESC(nonblock_open, "Don't block opening busy PCM devices.");
+MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_PCM);
+MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_PCM1);
+
+static int snd_pcm_oss_get_rate(struct snd_pcm_oss_file *pcm_oss_file);
+static int snd_pcm_oss_get_channels(struct snd_pcm_oss_file *pcm_oss_file);
+static int snd_pcm_oss_get_format(struct snd_pcm_oss_file *pcm_oss_file);
+
+/*
+ * helper functions to process hw_params
+ */
+static int snd_interval_refine_min(struct snd_interval *i, unsigned int min, int openmin)
+{
+	int changed = 0;
+	if (i->min < min) {
+		i->min = min;
+		i->openmin = openmin;
+		changed = 1;
+	} else if (i->min == min && !i->openmin && openmin) {
+		i->openmin = 1;
+		changed = 1;
+	}
+	if (i->integer) {
+		if (i->openmin) {
+			i->min++;
+			i->openmin = 0;
+		}
+	}
+	if (snd_interval_checkempty(i)) {
+		snd_interval_none(i);
+		return -EINVAL;
+	}
+	return changed;
+}
+
+static int snd_interval_refine_max(struct snd_interval *i, unsigned int max, int openmax)
+{
+	int changed = 0;
+	if (i->max > max) {
+		i->max = max;
+		i->openmax = openmax;
+		changed = 1;
+	} else if (i->max == max && !i->openmax && openmax) {
+		i->openmax = 1;
+		changed = 1;
+	}
+	if (i->integer) {
+		if (i->openmax) {
+			i->max--;
+			i->openmax = 0;
+		}
+	}
+	if (snd_interval_checkempty(i)) {
+		snd_interval_none(i);
+		return -EINVAL;
+	}
+	return changed;
+}
+
+static int snd_interval_refine_set(struct snd_interval *i, unsigned int val)
+{
+	struct snd_interval t;
+	t.empty = 0;
+	t.min = t.max = val;
+	t.openmin = t.openmax = 0;
+	t.integer = 1;
+	return snd_interval_refine(i, &t);
+}
+
+/**
+ * snd_pcm_hw_param_value_min
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @dir: pointer to the direction (-1,0,1) or NULL
+ *
+ * Return the minimum value for field PAR.
+ */
+static unsigned int
+snd_pcm_hw_param_value_min(const struct snd_pcm_hw_params *params,
+			   snd_pcm_hw_param_t var, int *dir)
+{
+	if (hw_is_mask(var)) {
+		if (dir)
+			*dir = 0;
+		return snd_mask_min(hw_param_mask_c(params, var));
+	}
+	if (hw_is_interval(var)) {
+		const struct snd_interval *i = hw_param_interval_c(params, var);
+		if (dir)
+			*dir = i->openmin;
+		return snd_interval_min(i);
+	}
+	return -EINVAL;
+}
+
+/**
+ * snd_pcm_hw_param_value_max
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @dir: pointer to the direction (-1,0,1) or NULL
+ *
+ * Return the maximum value for field PAR.
+ */
+static int
+snd_pcm_hw_param_value_max(const struct snd_pcm_hw_params *params,
+			   snd_pcm_hw_param_t var, int *dir)
+{
+	if (hw_is_mask(var)) {
+		if (dir)
+			*dir = 0;
+		return snd_mask_max(hw_param_mask_c(params, var));
+	}
+	if (hw_is_interval(var)) {
+		const struct snd_interval *i = hw_param_interval_c(params, var);
+		if (dir)
+			*dir = - (int) i->openmax;
+		return snd_interval_max(i);
+	}
+	return -EINVAL;
+}
+
+static int _snd_pcm_hw_param_mask(struct snd_pcm_hw_params *params,
+				  snd_pcm_hw_param_t var,
+				  const struct snd_mask *val)
+{
+	int changed;
+	changed = snd_mask_refine(hw_param_mask(params, var), val);
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+
+static int snd_pcm_hw_param_mask(struct snd_pcm_substream *pcm,
+				 struct snd_pcm_hw_params *params,
+				 snd_pcm_hw_param_t var,
+				 const struct snd_mask *val)
+{
+	int changed = _snd_pcm_hw_param_mask(params, var, val);
+	if (changed < 0)
+		return changed;
+	if (params->rmask) {
+		int err = snd_pcm_hw_refine(pcm, params);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+static int _snd_pcm_hw_param_min(struct snd_pcm_hw_params *params,
+				 snd_pcm_hw_param_t var, unsigned int val,
+				 int dir)
+{
+	int changed;
+	int open = 0;
+	if (dir) {
+		if (dir > 0) {
+			open = 1;
+		} else if (dir < 0) {
+			if (val > 0) {
+				open = 1;
+				val--;
+			}
+		}
+	}
+	if (hw_is_mask(var))
+		changed = snd_mask_refine_min(hw_param_mask(params, var),
+					      val + !!open);
+	else if (hw_is_interval(var))
+		changed = snd_interval_refine_min(hw_param_interval(params, var),
+						  val, open);
+	else
+		return -EINVAL;
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+
+/**
+ * snd_pcm_hw_param_min
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @val: minimal value
+ * @dir: pointer to the direction (-1,0,1) or NULL
+ *
+ * Inside configuration space defined by PARAMS remove from PAR all 
+ * values < VAL. Reduce configuration space accordingly.
+ * Return new minimum or -EINVAL if the configuration space is empty
+ */
+static int snd_pcm_hw_param_min(struct snd_pcm_substream *pcm,
+				struct snd_pcm_hw_params *params,
+				snd_pcm_hw_param_t var, unsigned int val,
+				int *dir)
+{
+	int changed = _snd_pcm_hw_param_min(params, var, val, dir ? *dir : 0);
+	if (changed < 0)
+		return changed;
+	if (params->rmask) {
+		int err = snd_pcm_hw_refine(pcm, params);
+		if (err < 0)
+			return err;
+	}
+	return snd_pcm_hw_param_value_min(params, var, dir);
+}
+
+static int _snd_pcm_hw_param_max(struct snd_pcm_hw_params *params,
+				 snd_pcm_hw_param_t var, unsigned int val,
+				 int dir)
+{
+	int changed;
+	int open = 0;
+	if (dir) {
+		if (dir < 0) {
+			open = 1;
+		} else if (dir > 0) {
+			open = 1;
+			val++;
+		}
+	}
+	if (hw_is_mask(var)) {
+		if (val == 0 && open) {
+			snd_mask_none(hw_param_mask(params, var));
+			changed = -EINVAL;
+		} else
+			changed = snd_mask_refine_max(hw_param_mask(params, var),
+						      val - !!open);
+	} else if (hw_is_interval(var))
+		changed = snd_interval_refine_max(hw_param_interval(params, var),
+						  val, open);
+	else
+		return -EINVAL;
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+
+/**
+ * snd_pcm_hw_param_max
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @val: maximal value
+ * @dir: pointer to the direction (-1,0,1) or NULL
+ *
+ * Inside configuration space defined by PARAMS remove from PAR all 
+ *  values >= VAL + 1. Reduce configuration space accordingly.
+ *  Return new maximum or -EINVAL if the configuration space is empty
+ */
+static int snd_pcm_hw_param_max(struct snd_pcm_substream *pcm,
+				struct snd_pcm_hw_params *params,
+				snd_pcm_hw_param_t var, unsigned int val,
+				int *dir)
+{
+	int changed = _snd_pcm_hw_param_max(params, var, val, dir ? *dir : 0);
+	if (changed < 0)
+		return changed;
+	if (params->rmask) {
+		int err = snd_pcm_hw_refine(pcm, params);
+		if (err < 0)
+			return err;
+	}
+	return snd_pcm_hw_param_value_max(params, var, dir);
+}
+
+static int boundary_sub(int a, int adir,
+			int b, int bdir,
+			int *c, int *cdir)
+{
+	adir = adir < 0 ? -1 : (adir > 0 ? 1 : 0);
+	bdir = bdir < 0 ? -1 : (bdir > 0 ? 1 : 0);
+	*c = a - b;
+	*cdir = adir - bdir;
+	if (*cdir == -2) {
+		(*c)--;
+	} else if (*cdir == 2) {
+		(*c)++;
+	}
+	return 0;
+}
+
+static int boundary_lt(unsigned int a, int adir,
+		       unsigned int b, int bdir)
+{
+	if (adir < 0) {
+		a--;
+		adir = 1;
+	} else if (adir > 0)
+		adir = 1;
+	if (bdir < 0) {
+		b--;
+		bdir = 1;
+	} else if (bdir > 0)
+		bdir = 1;
+	return a < b || (a == b && adir < bdir);
+}
+
+/* Return 1 if min is nearer to best than max */
+static int boundary_nearer(int min, int mindir,
+			   int best, int bestdir,
+			   int max, int maxdir)
+{
+	int dmin, dmindir;
+	int dmax, dmaxdir;
+	boundary_sub(best, bestdir, min, mindir, &dmin, &dmindir);
+	boundary_sub(max, maxdir, best, bestdir, &dmax, &dmaxdir);
+	return boundary_lt(dmin, dmindir, dmax, dmaxdir);
+}
+
+/**
+ * snd_pcm_hw_param_near
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @best: value to set
+ * @dir: pointer to the direction (-1,0,1) or NULL
+ *
+ * Inside configuration space defined by PARAMS set PAR to the available value
+ * nearest to VAL. Reduce configuration space accordingly.
+ * This function cannot be called for SNDRV_PCM_HW_PARAM_ACCESS,
+ * SNDRV_PCM_HW_PARAM_FORMAT, SNDRV_PCM_HW_PARAM_SUBFORMAT.
+ * Return the value found.
+  */
+static int snd_pcm_hw_param_near(struct snd_pcm_substream *pcm,
+				 struct snd_pcm_hw_params *params,
+				 snd_pcm_hw_param_t var, unsigned int best,
+				 int *dir)
+{
+	struct snd_pcm_hw_params *save = NULL;
+	int v;
+	unsigned int saved_min;
+	int last = 0;
+	int min, max;
+	int mindir, maxdir;
+	int valdir = dir ? *dir : 0;
+	/* FIXME */
+	if (best > INT_MAX)
+		best = INT_MAX;
+	min = max = best;
+	mindir = maxdir = valdir;
+	if (maxdir > 0)
+		maxdir = 0;
+	else if (maxdir == 0)
+		maxdir = -1;
+	else {
+		maxdir = 1;
+		max--;
+	}
+	save = kmalloc(sizeof(*save), GFP_KERNEL);
+	if (save == NULL)
+		return -ENOMEM;
+	*save = *params;
+	saved_min = min;
+	min = snd_pcm_hw_param_min(pcm, params, var, min, &mindir);
+	if (min >= 0) {
+		struct snd_pcm_hw_params *params1;
+		if (max < 0)
+			goto _end;
+		if ((unsigned int)min == saved_min && mindir == valdir)
+			goto _end;
+		params1 = kmalloc(sizeof(*params1), GFP_KERNEL);
+		if (params1 == NULL) {
+			kfree(save);
+			return -ENOMEM;
+		}
+		*params1 = *save;
+		max = snd_pcm_hw_param_max(pcm, params1, var, max, &maxdir);
+		if (max < 0) {
+			kfree(params1);
+			goto _end;
+		}
+		if (boundary_nearer(max, maxdir, best, valdir, min, mindir)) {
+			*params = *params1;
+			last = 1;
+		}
+		kfree(params1);
+	} else {
+		*params = *save;
+		max = snd_pcm_hw_param_max(pcm, params, var, max, &maxdir);
+		if (max < 0) {
+			kfree(save);
+			return max;
+		}
+		last = 1;
+	}
+ _end:
+ 	kfree(save);
+	if (last)
+		v = snd_pcm_hw_param_last(pcm, params, var, dir);
+	else
+		v = snd_pcm_hw_param_first(pcm, params, var, dir);
+	return v;
+}
+
+static int _snd_pcm_hw_param_set(struct snd_pcm_hw_params *params,
+				 snd_pcm_hw_param_t var, unsigned int val,
+				 int dir)
+{
+	int changed;
+	if (hw_is_mask(var)) {
+		struct snd_mask *m = hw_param_mask(params, var);
+		if (val == 0 && dir < 0) {
+			changed = -EINVAL;
+			snd_mask_none(m);
+		} else {
+			if (dir > 0)
+				val++;
+			else if (dir < 0)
+				val--;
+			changed = snd_mask_refine_set(hw_param_mask(params, var), val);
+		}
+	} else if (hw_is_interval(var)) {
+		struct snd_interval *i = hw_param_interval(params, var);
+		if (val == 0 && dir < 0) {
+			changed = -EINVAL;
+			snd_interval_none(i);
+		} else if (dir == 0)
+			changed = snd_interval_refine_set(i, val);
+		else {
+			struct snd_interval t;
+			t.openmin = 1;
+			t.openmax = 1;
+			t.empty = 0;
+			t.integer = 0;
+			if (dir < 0) {
+				t.min = val - 1;
+				t.max = val;
+			} else {
+				t.min = val;
+				t.max = val+1;
+			}
+			changed = snd_interval_refine(i, &t);
+		}
+	} else
+		return -EINVAL;
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+
+/**
+ * snd_pcm_hw_param_set
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @val: value to set
+ * @dir: pointer to the direction (-1,0,1) or NULL
+ *
+ * Inside configuration space defined by PARAMS remove from PAR all 
+ * values != VAL. Reduce configuration space accordingly.
+ *  Return VAL or -EINVAL if the configuration space is empty
+ */
+static int snd_pcm_hw_param_set(struct snd_pcm_substream *pcm,
+				struct snd_pcm_hw_params *params,
+				snd_pcm_hw_param_t var, unsigned int val,
+				int dir)
+{
+	int changed = _snd_pcm_hw_param_set(params, var, val, dir);
+	if (changed < 0)
+		return changed;
+	if (params->rmask) {
+		int err = snd_pcm_hw_refine(pcm, params);
+		if (err < 0)
+			return err;
+	}
+	return snd_pcm_hw_param_value(params, var, NULL);
+}
+
+static int _snd_pcm_hw_param_setinteger(struct snd_pcm_hw_params *params,
+					snd_pcm_hw_param_t var)
+{
+	int changed;
+	changed = snd_interval_setinteger(hw_param_interval(params, var));
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+	
+/*
+ * plugin
+ */
+
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+static int snd_pcm_oss_plugin_clear(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_plugin *plugin, *next;
+	
+	plugin = runtime->oss.plugin_first;
+	while (plugin) {
+		next = plugin->next;
+		snd_pcm_plugin_free(plugin);
+		plugin = next;
+	}
+	runtime->oss.plugin_first = runtime->oss.plugin_last = NULL;
+	return 0;
+}
+
+static int snd_pcm_plugin_insert(struct snd_pcm_plugin *plugin)
+{
+	struct snd_pcm_runtime *runtime = plugin->plug->runtime;
+	plugin->next = runtime->oss.plugin_first;
+	plugin->prev = NULL;
+	if (runtime->oss.plugin_first) {
+		runtime->oss.plugin_first->prev = plugin;
+		runtime->oss.plugin_first = plugin;
+	} else {
+		runtime->oss.plugin_last =
+		runtime->oss.plugin_first = plugin;
+	}
+	return 0;
+}
+
+int snd_pcm_plugin_append(struct snd_pcm_plugin *plugin)
+{
+	struct snd_pcm_runtime *runtime = plugin->plug->runtime;
+	plugin->next = NULL;
+	plugin->prev = runtime->oss.plugin_last;
+	if (runtime->oss.plugin_last) {
+		runtime->oss.plugin_last->next = plugin;
+		runtime->oss.plugin_last = plugin;
+	} else {
+		runtime->oss.plugin_last =
+		runtime->oss.plugin_first = plugin;
+	}
+	return 0;
+}
+#endif /* CONFIG_SND_PCM_OSS_PLUGINS */
+
+static long snd_pcm_oss_bytes(struct snd_pcm_substream *substream, long frames)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	long buffer_size = snd_pcm_lib_buffer_bytes(substream);
+	long bytes = frames_to_bytes(runtime, frames);
+	if (buffer_size == runtime->oss.buffer_bytes)
+		return bytes;
+#if BITS_PER_LONG >= 64
+	return runtime->oss.buffer_bytes * bytes / buffer_size;
+#else
+	{
+		u64 bsize = (u64)runtime->oss.buffer_bytes * (u64)bytes;
+		return div_u64(bsize, buffer_size);
+	}
+#endif
+}
+
+static long snd_pcm_alsa_frames(struct snd_pcm_substream *substream, long bytes)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	long buffer_size = snd_pcm_lib_buffer_bytes(substream);
+	if (buffer_size == runtime->oss.buffer_bytes)
+		return bytes_to_frames(runtime, bytes);
+	return bytes_to_frames(runtime, (buffer_size * bytes) / runtime->oss.buffer_bytes);
+}
+
+static inline
+snd_pcm_uframes_t get_hw_ptr_period(struct snd_pcm_runtime *runtime)
+{
+	return runtime->hw_ptr_interrupt;
+}
+
+/* define extended formats in the recent OSS versions (if any) */
+/* linear formats */
+#define AFMT_S32_LE      0x00001000
+#define AFMT_S32_BE      0x00002000
+#define AFMT_S24_LE      0x00008000
+#define AFMT_S24_BE      0x00010000
+#define AFMT_S24_PACKED  0x00040000
+
+/* other supported formats */
+#define AFMT_FLOAT       0x00004000
+#define AFMT_SPDIF_RAW   0x00020000
+
+/* unsupported formats */
+#define AFMT_AC3         0x00000400
+#define AFMT_VORBIS      0x00000800
+
+static snd_pcm_format_t snd_pcm_oss_format_from(int format)
+{
+	switch (format) {
+	case AFMT_MU_LAW:	return SNDRV_PCM_FORMAT_MU_LAW;
+	case AFMT_A_LAW:	return SNDRV_PCM_FORMAT_A_LAW;
+	case AFMT_IMA_ADPCM:	return SNDRV_PCM_FORMAT_IMA_ADPCM;
+	case AFMT_U8:		return SNDRV_PCM_FORMAT_U8;
+	case AFMT_S16_LE:	return SNDRV_PCM_FORMAT_S16_LE;
+	case AFMT_S16_BE:	return SNDRV_PCM_FORMAT_S16_BE;
+	case AFMT_S8:		return SNDRV_PCM_FORMAT_S8;
+	case AFMT_U16_LE:	return SNDRV_PCM_FORMAT_U16_LE;
+	case AFMT_U16_BE:	return SNDRV_PCM_FORMAT_U16_BE;
+	case AFMT_MPEG:		return SNDRV_PCM_FORMAT_MPEG;
+	case AFMT_S32_LE:	return SNDRV_PCM_FORMAT_S32_LE;
+	case AFMT_S32_BE:	return SNDRV_PCM_FORMAT_S32_BE;
+	case AFMT_S24_LE:	return SNDRV_PCM_FORMAT_S24_LE;
+	case AFMT_S24_BE:	return SNDRV_PCM_FORMAT_S24_BE;
+	case AFMT_S24_PACKED:	return SNDRV_PCM_FORMAT_S24_3LE;
+	case AFMT_FLOAT:	return SNDRV_PCM_FORMAT_FLOAT;
+	case AFMT_SPDIF_RAW:	return SNDRV_PCM_FORMAT_IEC958_SUBFRAME;
+	default:		return SNDRV_PCM_FORMAT_U8;
+	}
+}
+
+static int snd_pcm_oss_format_to(snd_pcm_format_t format)
+{
+	switch (format) {
+	case SNDRV_PCM_FORMAT_MU_LAW:	return AFMT_MU_LAW;
+	case SNDRV_PCM_FORMAT_A_LAW:	return AFMT_A_LAW;
+	case SNDRV_PCM_FORMAT_IMA_ADPCM:	return AFMT_IMA_ADPCM;
+	case SNDRV_PCM_FORMAT_U8:		return AFMT_U8;
+	case SNDRV_PCM_FORMAT_S16_LE:	return AFMT_S16_LE;
+	case SNDRV_PCM_FORMAT_S16_BE:	return AFMT_S16_BE;
+	case SNDRV_PCM_FORMAT_S8:		return AFMT_S8;
+	case SNDRV_PCM_FORMAT_U16_LE:	return AFMT_U16_LE;
+	case SNDRV_PCM_FORMAT_U16_BE:	return AFMT_U16_BE;
+	case SNDRV_PCM_FORMAT_MPEG:		return AFMT_MPEG;
+	case SNDRV_PCM_FORMAT_S32_LE:	return AFMT_S32_LE;
+	case SNDRV_PCM_FORMAT_S32_BE:	return AFMT_S32_BE;
+	case SNDRV_PCM_FORMAT_S24_LE:	return AFMT_S24_LE;
+	case SNDRV_PCM_FORMAT_S24_BE:	return AFMT_S24_BE;
+	case SNDRV_PCM_FORMAT_S24_3LE:	return AFMT_S24_PACKED;
+	case SNDRV_PCM_FORMAT_FLOAT:	return AFMT_FLOAT;
+	case SNDRV_PCM_FORMAT_IEC958_SUBFRAME: return AFMT_SPDIF_RAW;
+	default:			return -EINVAL;
+	}
+}
+
+static int snd_pcm_oss_period_size(struct snd_pcm_substream *substream, 
+				   struct snd_pcm_hw_params *oss_params,
+				   struct snd_pcm_hw_params *slave_params)
+{
+	ssize_t s;
+	ssize_t oss_buffer_size;
+	ssize_t oss_period_size, oss_periods;
+	ssize_t min_period_size, max_period_size;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	size_t oss_frame_size;
+
+	oss_frame_size = snd_pcm_format_physical_width(params_format(oss_params)) *
+			 params_channels(oss_params) / 8;
+
+	oss_buffer_size = snd_pcm_hw_param_value_max(slave_params,
+						     SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+						     NULL);
+	if (oss_buffer_size <= 0)
+		return -EINVAL;
+	oss_buffer_size = snd_pcm_plug_client_size(substream,
+						   oss_buffer_size * oss_frame_size);
+	if (oss_buffer_size <= 0)
+		return -EINVAL;
+	oss_buffer_size = rounddown_pow_of_two(oss_buffer_size);
+	if (atomic_read(&substream->mmap_count)) {
+		if (oss_buffer_size > runtime->oss.mmap_bytes)
+			oss_buffer_size = runtime->oss.mmap_bytes;
+	}
+
+	if (substream->oss.setup.period_size > 16)
+		oss_period_size = substream->oss.setup.period_size;
+	else if (runtime->oss.fragshift) {
+		oss_period_size = 1 << runtime->oss.fragshift;
+		if (oss_period_size > oss_buffer_size / 2)
+			oss_period_size = oss_buffer_size / 2;
+	} else {
+		int sd;
+		size_t bytes_per_sec = params_rate(oss_params) * snd_pcm_format_physical_width(params_format(oss_params)) * params_channels(oss_params) / 8;
+
+		oss_period_size = oss_buffer_size;
+		do {
+			oss_period_size /= 2;
+		} while (oss_period_size > bytes_per_sec);
+		if (runtime->oss.subdivision == 0) {
+			sd = 4;
+			if (oss_period_size / sd > 4096)
+				sd *= 2;
+			if (oss_period_size / sd < 4096)
+				sd = 1;
+		} else
+			sd = runtime->oss.subdivision;
+		oss_period_size /= sd;
+		if (oss_period_size < 16)
+			oss_period_size = 16;
+	}
+
+	min_period_size = snd_pcm_plug_client_size(substream,
+						   snd_pcm_hw_param_value_min(slave_params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, NULL));
+	if (min_period_size > 0) {
+		min_period_size *= oss_frame_size;
+		min_period_size = roundup_pow_of_two(min_period_size);
+		if (oss_period_size < min_period_size)
+			oss_period_size = min_period_size;
+	}
+
+	max_period_size = snd_pcm_plug_client_size(substream,
+						   snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, NULL));
+	if (max_period_size > 0) {
+		max_period_size *= oss_frame_size;
+		max_period_size = rounddown_pow_of_two(max_period_size);
+		if (oss_period_size > max_period_size)
+			oss_period_size = max_period_size;
+	}
+
+	oss_periods = oss_buffer_size / oss_period_size;
+
+	if (substream->oss.setup.periods > 1)
+		oss_periods = substream->oss.setup.periods;
+
+	s = snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_PERIODS, NULL);
+	if (s > 0 && runtime->oss.maxfrags && s > runtime->oss.maxfrags)
+		s = runtime->oss.maxfrags;
+	if (oss_periods > s)
+		oss_periods = s;
+
+	s = snd_pcm_hw_param_value_min(slave_params, SNDRV_PCM_HW_PARAM_PERIODS, NULL);
+	if (s < 2)
+		s = 2;
+	if (oss_periods < s)
+		oss_periods = s;
+
+	while (oss_period_size * oss_periods > oss_buffer_size)
+		oss_period_size /= 2;
+
+	if (oss_period_size < 16)
+		return -EINVAL;
+
+	/* don't allocate too large period; 1MB period must be enough */
+	if (oss_period_size > 1024 * 1024)
+		return -ENOMEM;
+
+	runtime->oss.period_bytes = oss_period_size;
+	runtime->oss.period_frames = 1;
+	runtime->oss.periods = oss_periods;
+	return 0;
+}
+
+static int choose_rate(struct snd_pcm_substream *substream,
+		       struct snd_pcm_hw_params *params, unsigned int best_rate)
+{
+	const struct snd_interval *it;
+	struct snd_pcm_hw_params *save;
+	unsigned int rate, prev;
+
+	save = kmalloc(sizeof(*save), GFP_KERNEL);
+	if (save == NULL)
+		return -ENOMEM;
+	*save = *params;
+	it = hw_param_interval_c(save, SNDRV_PCM_HW_PARAM_RATE);
+
+	/* try multiples of the best rate */
+	rate = best_rate;
+	for (;;) {
+		if (it->max < rate || (it->max == rate && it->openmax))
+			break;
+		if (it->min < rate || (it->min == rate && !it->openmin)) {
+			int ret;
+			ret = snd_pcm_hw_param_set(substream, params,
+						   SNDRV_PCM_HW_PARAM_RATE,
+						   rate, 0);
+			if (ret == (int)rate) {
+				kfree(save);
+				return rate;
+			}
+			*params = *save;
+		}
+		prev = rate;
+		rate += best_rate;
+		if (rate <= prev)
+			break;
+	}
+
+	/* not found, use the nearest rate */
+	kfree(save);
+	return snd_pcm_hw_param_near(substream, params, SNDRV_PCM_HW_PARAM_RATE, best_rate, NULL);
+}
+
+/* parameter locking: returns immediately if tried during streaming */
+static int lock_params(struct snd_pcm_runtime *runtime)
+{
+	if (mutex_lock_interruptible(&runtime->oss.params_lock))
+		return -ERESTARTSYS;
+	if (atomic_read(&runtime->oss.rw_ref)) {
+		mutex_unlock(&runtime->oss.params_lock);
+		return -EBUSY;
+	}
+	return 0;
+}
+
+static void unlock_params(struct snd_pcm_runtime *runtime)
+{
+	mutex_unlock(&runtime->oss.params_lock);
+}
+
+static void snd_pcm_oss_release_buffers(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	kvfree(runtime->oss.buffer);
+	runtime->oss.buffer = NULL;
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+	snd_pcm_oss_plugin_clear(substream);
+#endif
+}
+
+/* call with params_lock held */
+static int snd_pcm_oss_change_params_locked(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_hw_params *params, *sparams;
+	struct snd_pcm_sw_params *sw_params;
+	ssize_t oss_buffer_size, oss_period_size;
+	size_t oss_frame_size;
+	int err;
+	int direct;
+	snd_pcm_format_t format, sformat;
+	int n;
+	const struct snd_mask *sformat_mask;
+	struct snd_mask mask;
+
+	if (!runtime->oss.params)
+		return 0;
+	sw_params = kzalloc(sizeof(*sw_params), GFP_KERNEL);
+	params = kmalloc(sizeof(*params), GFP_KERNEL);
+	sparams = kmalloc(sizeof(*sparams), GFP_KERNEL);
+	if (!sw_params || !params || !sparams) {
+		err = -ENOMEM;
+		goto failure;
+	}
+
+	if (atomic_read(&substream->mmap_count))
+		direct = 1;
+	else
+		direct = substream->oss.setup.direct;
+
+	_snd_pcm_hw_params_any(sparams);
+	_snd_pcm_hw_param_setinteger(sparams, SNDRV_PCM_HW_PARAM_PERIODS);
+	_snd_pcm_hw_param_min(sparams, SNDRV_PCM_HW_PARAM_PERIODS, 2, 0);
+	snd_mask_none(&mask);
+	if (atomic_read(&substream->mmap_count))
+		snd_mask_set(&mask, (__force int)SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
+	else {
+		snd_mask_set(&mask, (__force int)SNDRV_PCM_ACCESS_RW_INTERLEAVED);
+		if (!direct)
+			snd_mask_set(&mask, (__force int)SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
+	}
+	err = snd_pcm_hw_param_mask(substream, sparams, SNDRV_PCM_HW_PARAM_ACCESS, &mask);
+	if (err < 0) {
+		pcm_dbg(substream->pcm, "No usable accesses\n");
+		err = -EINVAL;
+		goto failure;
+	}
+
+	err = choose_rate(substream, sparams, runtime->oss.rate);
+	if (err < 0)
+		goto failure;
+	err = snd_pcm_hw_param_near(substream, sparams,
+				    SNDRV_PCM_HW_PARAM_CHANNELS,
+				    runtime->oss.channels, NULL);
+	if (err < 0)
+		goto failure;
+
+	format = snd_pcm_oss_format_from(runtime->oss.format);
+
+	sformat_mask = hw_param_mask_c(sparams, SNDRV_PCM_HW_PARAM_FORMAT);
+	if (direct)
+		sformat = format;
+	else
+		sformat = snd_pcm_plug_slave_format(format, sformat_mask);
+
+	if ((__force int)sformat < 0 ||
+	    !snd_mask_test_format(sformat_mask, sformat)) {
+		pcm_for_each_format(sformat) {
+			if (snd_mask_test_format(sformat_mask, sformat) &&
+			    snd_pcm_oss_format_to(sformat) >= 0)
+				goto format_found;
+		}
+		pcm_dbg(substream->pcm, "Cannot find a format!!!\n");
+		err = -EINVAL;
+		goto failure;
+	}
+ format_found:
+	err = _snd_pcm_hw_param_set(sparams, SNDRV_PCM_HW_PARAM_FORMAT, (__force int)sformat, 0);
+	if (err < 0)
+		goto failure;
+
+	if (direct) {
+		memcpy(params, sparams, sizeof(*params));
+	} else {
+		_snd_pcm_hw_params_any(params);
+		_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_ACCESS,
+				      (__force int)SNDRV_PCM_ACCESS_RW_INTERLEAVED, 0);
+		_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_FORMAT,
+				      (__force int)snd_pcm_oss_format_from(runtime->oss.format), 0);
+		_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_CHANNELS,
+				      runtime->oss.channels, 0);
+		_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_RATE,
+				      runtime->oss.rate, 0);
+		pdprintf("client: access = %i, format = %i, channels = %i, rate = %i\n",
+			 params_access(params), params_format(params),
+			 params_channels(params), params_rate(params));
+	}
+	pdprintf("slave: access = %i, format = %i, channels = %i, rate = %i\n",
+		 params_access(sparams), params_format(sparams),
+		 params_channels(sparams), params_rate(sparams));
+
+	oss_frame_size = snd_pcm_format_physical_width(params_format(params)) *
+			 params_channels(params) / 8;
+
+	err = snd_pcm_oss_period_size(substream, params, sparams);
+	if (err < 0)
+		goto failure;
+
+	n = snd_pcm_plug_slave_size(substream, runtime->oss.period_bytes / oss_frame_size);
+	err = snd_pcm_hw_param_near(substream, sparams, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, n, NULL);
+	if (err < 0)
+		goto failure;
+
+	err = snd_pcm_hw_param_near(substream, sparams, SNDRV_PCM_HW_PARAM_PERIODS,
+				     runtime->oss.periods, NULL);
+	if (err < 0)
+		goto failure;
+
+	snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
+
+	err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_HW_PARAMS, sparams);
+	if (err < 0) {
+		pcm_dbg(substream->pcm, "HW_PARAMS failed: %i\n", err);
+		goto failure;
+	}
+
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+	snd_pcm_oss_plugin_clear(substream);
+	if (!direct) {
+		/* add necessary plugins */
+		err = snd_pcm_plug_format_plugins(substream, params, sparams);
+		if (err < 0) {
+			pcm_dbg(substream->pcm,
+				"snd_pcm_plug_format_plugins failed: %i\n", err);
+			goto failure;
+		}
+		if (runtime->oss.plugin_first) {
+			struct snd_pcm_plugin *plugin;
+			err = snd_pcm_plugin_build_io(substream, sparams, &plugin);
+			if (err < 0) {
+				pcm_dbg(substream->pcm,
+					"snd_pcm_plugin_build_io failed: %i\n", err);
+				goto failure;
+			}
+			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+				err = snd_pcm_plugin_append(plugin);
+			} else {
+				err = snd_pcm_plugin_insert(plugin);
+			}
+			if (err < 0)
+				goto failure;
+		}
+	}
+#endif
+
+	if (runtime->oss.trigger) {
+		sw_params->start_threshold = 1;
+	} else {
+		sw_params->start_threshold = runtime->boundary;
+	}
+	if (atomic_read(&substream->mmap_count) ||
+	    substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+		sw_params->stop_threshold = runtime->boundary;
+	else
+		sw_params->stop_threshold = runtime->buffer_size;
+	sw_params->tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
+	sw_params->period_step = 1;
+	sw_params->avail_min = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
+		1 : runtime->period_size;
+	if (atomic_read(&substream->mmap_count) ||
+	    substream->oss.setup.nosilence) {
+		sw_params->silence_threshold = 0;
+		sw_params->silence_size = 0;
+	} else {
+		snd_pcm_uframes_t frames;
+		frames = runtime->period_size + 16;
+		if (frames > runtime->buffer_size)
+			frames = runtime->buffer_size;
+		sw_params->silence_threshold = frames;
+		sw_params->silence_size = frames;
+	}
+
+	err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_SW_PARAMS, sw_params);
+	if (err < 0) {
+		pcm_dbg(substream->pcm, "SW_PARAMS failed: %i\n", err);
+		goto failure;
+	}
+
+	runtime->oss.periods = params_periods(sparams);
+	oss_period_size = snd_pcm_plug_client_size(substream, params_period_size(sparams));
+	if (oss_period_size < 0) {
+		err = -EINVAL;
+		goto failure;
+	}
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+	if (runtime->oss.plugin_first) {
+		err = snd_pcm_plug_alloc(substream, oss_period_size);
+		if (err < 0)
+			goto failure;
+	}
+#endif
+	oss_period_size = array_size(oss_period_size, oss_frame_size);
+	oss_buffer_size = array_size(oss_period_size, runtime->oss.periods);
+	if (oss_buffer_size <= 0) {
+		err = -EINVAL;
+		goto failure;
+	}
+
+	runtime->oss.period_bytes = oss_period_size;
+	runtime->oss.buffer_bytes = oss_buffer_size;
+
+	pdprintf("oss: period bytes = %i, buffer bytes = %i\n",
+		 runtime->oss.period_bytes,
+		 runtime->oss.buffer_bytes);
+	pdprintf("slave: period_size = %i, buffer_size = %i\n",
+		 params_period_size(sparams),
+		 params_buffer_size(sparams));
+
+	runtime->oss.format = snd_pcm_oss_format_to(params_format(params));
+	runtime->oss.channels = params_channels(params);
+	runtime->oss.rate = params_rate(params);
+
+	kvfree(runtime->oss.buffer);
+	runtime->oss.buffer = kvzalloc(runtime->oss.period_bytes, GFP_KERNEL);
+	if (!runtime->oss.buffer) {
+		err = -ENOMEM;
+		goto failure;
+	}
+
+	runtime->oss.params = 0;
+	runtime->oss.prepare = 1;
+	runtime->oss.buffer_used = 0;
+	if (runtime->dma_area)
+		snd_pcm_format_set_silence(runtime->format, runtime->dma_area, bytes_to_samples(runtime, runtime->dma_bytes));
+
+	runtime->oss.period_frames = snd_pcm_alsa_frames(substream, oss_period_size);
+
+	err = 0;
+failure:
+	if (err)
+		snd_pcm_oss_release_buffers(substream);
+	kfree(sw_params);
+	kfree(params);
+	kfree(sparams);
+	return err;
+}
+
+/* this one takes the lock by itself */
+static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream,
+				     bool trylock)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err;
+
+	if (trylock) {
+		if (!(mutex_trylock(&runtime->oss.params_lock)))
+			return -EAGAIN;
+	} else if (mutex_lock_interruptible(&runtime->oss.params_lock))
+		return -ERESTARTSYS;
+
+	err = snd_pcm_oss_change_params_locked(substream);
+	mutex_unlock(&runtime->oss.params_lock);
+	return err;
+}
+
+static int snd_pcm_oss_get_active_substream(struct snd_pcm_oss_file *pcm_oss_file, struct snd_pcm_substream **r_substream)
+{
+	int idx, err;
+	struct snd_pcm_substream *asubstream = NULL, *substream;
+
+	for (idx = 0; idx < 2; idx++) {
+		substream = pcm_oss_file->streams[idx];
+		if (substream == NULL)
+			continue;
+		if (asubstream == NULL)
+			asubstream = substream;
+		if (substream->runtime->oss.params) {
+			err = snd_pcm_oss_change_params(substream, false);
+			if (err < 0)
+				return err;
+		}
+	}
+	if (!asubstream)
+		return -EIO;
+	if (r_substream)
+		*r_substream = asubstream;
+	return 0;
+}
+
+/* call with params_lock held */
+/* NOTE: this always call PREPARE unconditionally no matter whether
+ * runtime->oss.prepare is set or not
+ */
+static int snd_pcm_oss_prepare(struct snd_pcm_substream *substream)
+{
+	int err;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL);
+	if (err < 0) {
+		pcm_dbg(substream->pcm,
+			"snd_pcm_oss_prepare: SNDRV_PCM_IOCTL_PREPARE failed\n");
+		return err;
+	}
+	runtime->oss.prepare = 0;
+	runtime->oss.prev_hw_ptr_period = 0;
+	runtime->oss.period_ptr = 0;
+	runtime->oss.buffer_used = 0;
+
+	return 0;
+}
+
+static int snd_pcm_oss_make_ready(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+	int err;
+
+	runtime = substream->runtime;
+	if (runtime->oss.params) {
+		err = snd_pcm_oss_change_params(substream, false);
+		if (err < 0)
+			return err;
+	}
+	if (runtime->oss.prepare) {
+		if (mutex_lock_interruptible(&runtime->oss.params_lock))
+			return -ERESTARTSYS;
+		err = snd_pcm_oss_prepare(substream);
+		mutex_unlock(&runtime->oss.params_lock);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/* call with params_lock held */
+static int snd_pcm_oss_make_ready_locked(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+	int err;
+
+	runtime = substream->runtime;
+	if (runtime->oss.params) {
+		err = snd_pcm_oss_change_params_locked(substream);
+		if (err < 0)
+			return err;
+	}
+	if (runtime->oss.prepare) {
+		err = snd_pcm_oss_prepare(substream);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+static int snd_pcm_oss_capture_position_fixup(struct snd_pcm_substream *substream, snd_pcm_sframes_t *delay)
+{
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_uframes_t frames;
+	int err = 0;
+
+	while (1) {
+		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, delay);
+		if (err < 0)
+			break;
+		runtime = substream->runtime;
+		if (*delay <= (snd_pcm_sframes_t)runtime->buffer_size)
+			break;
+		/* in case of overrun, skip whole periods like OSS/Linux driver does */
+		/* until avail(delay) <= buffer_size */
+		frames = (*delay - runtime->buffer_size) + runtime->period_size - 1;
+		frames /= runtime->period_size;
+		frames *= runtime->period_size;
+		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_FORWARD, &frames);
+		if (err < 0)
+			break;
+	}
+	return err;
+}
+
+snd_pcm_sframes_t snd_pcm_oss_write3(struct snd_pcm_substream *substream, const char *ptr, snd_pcm_uframes_t frames, int in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int ret;
+	while (1) {
+		if (runtime->state == SNDRV_PCM_STATE_XRUN ||
+		    runtime->state == SNDRV_PCM_STATE_SUSPENDED) {
+#ifdef OSS_DEBUG
+			pcm_dbg(substream->pcm,
+				"pcm_oss: write: recovering from %s\n",
+				runtime->state == SNDRV_PCM_STATE_XRUN ?
+				"XRUN" : "SUSPEND");
+#endif
+			ret = snd_pcm_oss_prepare(substream);
+			if (ret < 0)
+				break;
+		}
+		mutex_unlock(&runtime->oss.params_lock);
+		ret = __snd_pcm_lib_xfer(substream, (void *)ptr, true,
+					 frames, in_kernel);
+		mutex_lock(&runtime->oss.params_lock);
+		if (ret != -EPIPE && ret != -ESTRPIPE)
+			break;
+		/* test, if we can't store new data, because the stream */
+		/* has not been started */
+		if (runtime->state == SNDRV_PCM_STATE_PREPARED)
+			return -EAGAIN;
+	}
+	return ret;
+}
+
+snd_pcm_sframes_t snd_pcm_oss_read3(struct snd_pcm_substream *substream, char *ptr, snd_pcm_uframes_t frames, int in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_sframes_t delay;
+	int ret;
+	while (1) {
+		if (runtime->state == SNDRV_PCM_STATE_XRUN ||
+		    runtime->state == SNDRV_PCM_STATE_SUSPENDED) {
+#ifdef OSS_DEBUG
+			pcm_dbg(substream->pcm,
+				"pcm_oss: read: recovering from %s\n",
+				runtime->state == SNDRV_PCM_STATE_XRUN ?
+				"XRUN" : "SUSPEND");
+#endif
+			ret = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
+			if (ret < 0)
+				break;
+		} else if (runtime->state == SNDRV_PCM_STATE_SETUP) {
+			ret = snd_pcm_oss_prepare(substream);
+			if (ret < 0)
+				break;
+		}
+		ret = snd_pcm_oss_capture_position_fixup(substream, &delay);
+		if (ret < 0)
+			break;
+		mutex_unlock(&runtime->oss.params_lock);
+		ret = __snd_pcm_lib_xfer(substream, (void *)ptr, true,
+					 frames, in_kernel);
+		mutex_lock(&runtime->oss.params_lock);
+		if (ret == -EPIPE) {
+			if (runtime->state == SNDRV_PCM_STATE_DRAINING) {
+				ret = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
+				if (ret < 0)
+					break;
+			}
+			continue;
+		}
+		if (ret != -ESTRPIPE)
+			break;
+	}
+	return ret;
+}
+
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+snd_pcm_sframes_t snd_pcm_oss_writev3(struct snd_pcm_substream *substream, void **bufs, snd_pcm_uframes_t frames)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int ret;
+	while (1) {
+		if (runtime->state == SNDRV_PCM_STATE_XRUN ||
+		    runtime->state == SNDRV_PCM_STATE_SUSPENDED) {
+#ifdef OSS_DEBUG
+			pcm_dbg(substream->pcm,
+				"pcm_oss: writev: recovering from %s\n",
+				runtime->state == SNDRV_PCM_STATE_XRUN ?
+				"XRUN" : "SUSPEND");
+#endif
+			ret = snd_pcm_oss_prepare(substream);
+			if (ret < 0)
+				break;
+		}
+		ret = snd_pcm_kernel_writev(substream, bufs, frames);
+		if (ret != -EPIPE && ret != -ESTRPIPE)
+			break;
+
+		/* test, if we can't store new data, because the stream */
+		/* has not been started */
+		if (runtime->state == SNDRV_PCM_STATE_PREPARED)
+			return -EAGAIN;
+	}
+	return ret;
+}
+	
+snd_pcm_sframes_t snd_pcm_oss_readv3(struct snd_pcm_substream *substream, void **bufs, snd_pcm_uframes_t frames)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int ret;
+	while (1) {
+		if (runtime->state == SNDRV_PCM_STATE_XRUN ||
+		    runtime->state == SNDRV_PCM_STATE_SUSPENDED) {
+#ifdef OSS_DEBUG
+			pcm_dbg(substream->pcm,
+				"pcm_oss: readv: recovering from %s\n",
+				runtime->state == SNDRV_PCM_STATE_XRUN ?
+				"XRUN" : "SUSPEND");
+#endif
+			ret = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
+			if (ret < 0)
+				break;
+		} else if (runtime->state == SNDRV_PCM_STATE_SETUP) {
+			ret = snd_pcm_oss_prepare(substream);
+			if (ret < 0)
+				break;
+		}
+		ret = snd_pcm_kernel_readv(substream, bufs, frames);
+		if (ret != -EPIPE && ret != -ESTRPIPE)
+			break;
+	}
+	return ret;
+}
+#endif /* CONFIG_SND_PCM_OSS_PLUGINS */
+
+static ssize_t snd_pcm_oss_write2(struct snd_pcm_substream *substream, const char *buf, size_t bytes, int in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_sframes_t frames, frames1;
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+	if (runtime->oss.plugin_first) {
+		struct snd_pcm_plugin_channel *channels;
+		size_t oss_frame_bytes = (runtime->oss.plugin_first->src_width * runtime->oss.plugin_first->src_format.channels) / 8;
+		if (!in_kernel) {
+			if (copy_from_user(runtime->oss.buffer, (const char __force __user *)buf, bytes))
+				return -EFAULT;
+			buf = runtime->oss.buffer;
+		}
+		frames = bytes / oss_frame_bytes;
+		frames1 = snd_pcm_plug_client_channels_buf(substream, (char *)buf, frames, &channels);
+		if (frames1 < 0)
+			return frames1;
+		frames1 = snd_pcm_plug_write_transfer(substream, channels, frames1);
+		if (frames1 <= 0)
+			return frames1;
+		bytes = frames1 * oss_frame_bytes;
+	} else
+#endif
+	{
+		frames = bytes_to_frames(runtime, bytes);
+		frames1 = snd_pcm_oss_write3(substream, buf, frames, in_kernel);
+		if (frames1 <= 0)
+			return frames1;
+		bytes = frames_to_bytes(runtime, frames1);
+	}
+	return bytes;
+}
+
+static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const char __user *buf, size_t bytes)
+{
+	size_t xfer = 0;
+	ssize_t tmp = 0;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	if (atomic_read(&substream->mmap_count))
+		return -ENXIO;
+
+	atomic_inc(&runtime->oss.rw_ref);
+	while (bytes > 0) {
+		if (mutex_lock_interruptible(&runtime->oss.params_lock)) {
+			tmp = -ERESTARTSYS;
+			break;
+		}
+		tmp = snd_pcm_oss_make_ready_locked(substream);
+		if (tmp < 0)
+			goto err;
+		if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
+			tmp = bytes;
+			if (tmp + runtime->oss.buffer_used > runtime->oss.period_bytes)
+				tmp = runtime->oss.period_bytes - runtime->oss.buffer_used;
+			if (tmp > 0) {
+				if (copy_from_user(runtime->oss.buffer + runtime->oss.buffer_used, buf, tmp)) {
+					tmp = -EFAULT;
+					goto err;
+				}
+			}
+			runtime->oss.buffer_used += tmp;
+			buf += tmp;
+			bytes -= tmp;
+			xfer += tmp;
+			if (substream->oss.setup.partialfrag ||
+			    runtime->oss.buffer_used == runtime->oss.period_bytes) {
+				tmp = snd_pcm_oss_write2(substream, runtime->oss.buffer + runtime->oss.period_ptr, 
+							 runtime->oss.buffer_used - runtime->oss.period_ptr, 1);
+				if (tmp <= 0)
+					goto err;
+				runtime->oss.bytes += tmp;
+				runtime->oss.period_ptr += tmp;
+				runtime->oss.period_ptr %= runtime->oss.period_bytes;
+				if (runtime->oss.period_ptr == 0 ||
+				    runtime->oss.period_ptr == runtime->oss.buffer_used)
+					runtime->oss.buffer_used = 0;
+				else if ((substream->f_flags & O_NONBLOCK) != 0) {
+					tmp = -EAGAIN;
+					goto err;
+				}
+			}
+		} else {
+			tmp = snd_pcm_oss_write2(substream,
+						 (const char __force *)buf,
+						 runtime->oss.period_bytes, 0);
+			if (tmp <= 0)
+				goto err;
+			runtime->oss.bytes += tmp;
+			buf += tmp;
+			bytes -= tmp;
+			xfer += tmp;
+			if ((substream->f_flags & O_NONBLOCK) != 0 &&
+			    tmp != runtime->oss.period_bytes)
+				tmp = -EAGAIN;
+		}
+ err:
+		mutex_unlock(&runtime->oss.params_lock);
+		if (tmp < 0)
+			break;
+		if (signal_pending(current)) {
+			tmp = -ERESTARTSYS;
+			break;
+		}
+		tmp = 0;
+	}
+	atomic_dec(&runtime->oss.rw_ref);
+	return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
+}
+
+static ssize_t snd_pcm_oss_read2(struct snd_pcm_substream *substream, char *buf, size_t bytes, int in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_sframes_t frames, frames1;
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+	char __user *final_dst = (char __force __user *)buf;
+	if (runtime->oss.plugin_first) {
+		struct snd_pcm_plugin_channel *channels;
+		size_t oss_frame_bytes = (runtime->oss.plugin_last->dst_width * runtime->oss.plugin_last->dst_format.channels) / 8;
+		if (!in_kernel)
+			buf = runtime->oss.buffer;
+		frames = bytes / oss_frame_bytes;
+		frames1 = snd_pcm_plug_client_channels_buf(substream, buf, frames, &channels);
+		if (frames1 < 0)
+			return frames1;
+		frames1 = snd_pcm_plug_read_transfer(substream, channels, frames1);
+		if (frames1 <= 0)
+			return frames1;
+		bytes = frames1 * oss_frame_bytes;
+		if (!in_kernel && copy_to_user(final_dst, buf, bytes))
+			return -EFAULT;
+	} else
+#endif
+	{
+		frames = bytes_to_frames(runtime, bytes);
+		frames1 = snd_pcm_oss_read3(substream, buf, frames, in_kernel);
+		if (frames1 <= 0)
+			return frames1;
+		bytes = frames_to_bytes(runtime, frames1);
+	}
+	return bytes;
+}
+
+static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __user *buf, size_t bytes)
+{
+	size_t xfer = 0;
+	ssize_t tmp = 0;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	if (atomic_read(&substream->mmap_count))
+		return -ENXIO;
+
+	atomic_inc(&runtime->oss.rw_ref);
+	while (bytes > 0) {
+		if (mutex_lock_interruptible(&runtime->oss.params_lock)) {
+			tmp = -ERESTARTSYS;
+			break;
+		}
+		tmp = snd_pcm_oss_make_ready_locked(substream);
+		if (tmp < 0)
+			goto err;
+		if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
+			if (runtime->oss.buffer_used == 0) {
+				tmp = snd_pcm_oss_read2(substream, runtime->oss.buffer, runtime->oss.period_bytes, 1);
+				if (tmp <= 0)
+					goto err;
+				runtime->oss.bytes += tmp;
+				runtime->oss.period_ptr = tmp;
+				runtime->oss.buffer_used = tmp;
+			}
+			tmp = bytes;
+			if ((size_t) tmp > runtime->oss.buffer_used)
+				tmp = runtime->oss.buffer_used;
+			if (copy_to_user(buf, runtime->oss.buffer + (runtime->oss.period_ptr - runtime->oss.buffer_used), tmp)) {
+				tmp = -EFAULT;
+				goto err;
+			}
+			buf += tmp;
+			bytes -= tmp;
+			xfer += tmp;
+			runtime->oss.buffer_used -= tmp;
+		} else {
+			tmp = snd_pcm_oss_read2(substream, (char __force *)buf,
+						runtime->oss.period_bytes, 0);
+			if (tmp <= 0)
+				goto err;
+			runtime->oss.bytes += tmp;
+			buf += tmp;
+			bytes -= tmp;
+			xfer += tmp;
+		}
+ err:
+		mutex_unlock(&runtime->oss.params_lock);
+		if (tmp < 0)
+			break;
+		if (signal_pending(current)) {
+			tmp = -ERESTARTSYS;
+			break;
+		}
+		tmp = 0;
+	}
+	atomic_dec(&runtime->oss.rw_ref);
+	return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
+}
+
+static int snd_pcm_oss_reset(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	int i;
+
+	for (i = 0; i < 2; i++) { 
+		substream = pcm_oss_file->streams[i];
+		if (!substream)
+			continue;
+		runtime = substream->runtime;
+		snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
+		mutex_lock(&runtime->oss.params_lock);
+		runtime->oss.prepare = 1;
+		runtime->oss.buffer_used = 0;
+		runtime->oss.prev_hw_ptr_period = 0;
+		runtime->oss.period_ptr = 0;
+		mutex_unlock(&runtime->oss.params_lock);
+	}
+	return 0;
+}
+
+static int snd_pcm_oss_post(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	if (substream != NULL) {
+		err = snd_pcm_oss_make_ready(substream);
+		if (err < 0)
+			return err;
+		snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_START, NULL);
+	}
+	/* note: all errors from the start action are ignored */
+	/* OSS apps do not know, how to handle them */
+	return 0;
+}
+
+static int snd_pcm_oss_sync1(struct snd_pcm_substream *substream, size_t size)
+{
+	struct snd_pcm_runtime *runtime;
+	ssize_t result = 0;
+	snd_pcm_state_t state;
+	long res;
+	wait_queue_entry_t wait;
+
+	runtime = substream->runtime;
+	init_waitqueue_entry(&wait, current);
+	add_wait_queue(&runtime->sleep, &wait);
+#ifdef OSS_DEBUG
+	pcm_dbg(substream->pcm, "sync1: size = %li\n", size);
+#endif
+	while (1) {
+		result = snd_pcm_oss_write2(substream, runtime->oss.buffer, size, 1);
+		if (result > 0) {
+			runtime->oss.buffer_used = 0;
+			result = 0;
+			break;
+		}
+		if (result != 0 && result != -EAGAIN)
+			break;
+		result = 0;
+		set_current_state(TASK_INTERRUPTIBLE);
+		snd_pcm_stream_lock_irq(substream);
+		state = runtime->state;
+		snd_pcm_stream_unlock_irq(substream);
+		if (state != SNDRV_PCM_STATE_RUNNING) {
+			set_current_state(TASK_RUNNING);
+			break;
+		}
+		res = schedule_timeout(10 * HZ);
+		if (signal_pending(current)) {
+			result = -ERESTARTSYS;
+			break;
+		}
+		if (res == 0) {
+			pcm_err(substream->pcm,
+				"OSS sync error - DMA timeout\n");
+			result = -EIO;
+			break;
+		}
+	}
+	remove_wait_queue(&runtime->sleep, &wait);
+	return result;
+}
+
+static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	int err = 0;
+	unsigned int saved_f_flags;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_format_t format;
+	unsigned long width;
+	size_t size;
+
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	if (substream != NULL) {
+		runtime = substream->runtime;
+		if (atomic_read(&substream->mmap_count))
+			goto __direct;
+		atomic_inc(&runtime->oss.rw_ref);
+		if (mutex_lock_interruptible(&runtime->oss.params_lock)) {
+			atomic_dec(&runtime->oss.rw_ref);
+			return -ERESTARTSYS;
+		}
+		err = snd_pcm_oss_make_ready_locked(substream);
+		if (err < 0)
+			goto unlock;
+		format = snd_pcm_oss_format_from(runtime->oss.format);
+		width = snd_pcm_format_physical_width(format);
+		if (runtime->oss.buffer_used > 0) {
+#ifdef OSS_DEBUG
+			pcm_dbg(substream->pcm, "sync: buffer_used\n");
+#endif
+			size = (8 * (runtime->oss.period_bytes - runtime->oss.buffer_used) + 7) / width;
+			snd_pcm_format_set_silence(format,
+						   runtime->oss.buffer + runtime->oss.buffer_used,
+						   size);
+			err = snd_pcm_oss_sync1(substream, runtime->oss.period_bytes);
+			if (err < 0)
+				goto unlock;
+		} else if (runtime->oss.period_ptr > 0) {
+#ifdef OSS_DEBUG
+			pcm_dbg(substream->pcm, "sync: period_ptr\n");
+#endif
+			size = runtime->oss.period_bytes - runtime->oss.period_ptr;
+			snd_pcm_format_set_silence(format,
+						   runtime->oss.buffer,
+						   size * 8 / width);
+			err = snd_pcm_oss_sync1(substream, size);
+			if (err < 0)
+				goto unlock;
+		}
+		/*
+		 * The ALSA's period might be a bit large than OSS one.
+		 * Fill the remain portion of ALSA period with zeros.
+		 */
+		size = runtime->control->appl_ptr % runtime->period_size;
+		if (size > 0) {
+			size = runtime->period_size - size;
+			if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)
+				snd_pcm_lib_write(substream, NULL, size);
+			else if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
+				snd_pcm_lib_writev(substream, NULL, size);
+		}
+unlock:
+		mutex_unlock(&runtime->oss.params_lock);
+		atomic_dec(&runtime->oss.rw_ref);
+		if (err < 0)
+			return err;
+		/*
+		 * finish sync: drain the buffer
+		 */
+	      __direct:
+		saved_f_flags = substream->f_flags;
+		substream->f_flags &= ~O_NONBLOCK;
+		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
+		substream->f_flags = saved_f_flags;
+		if (err < 0)
+			return err;
+		mutex_lock(&runtime->oss.params_lock);
+		runtime->oss.prepare = 1;
+		mutex_unlock(&runtime->oss.params_lock);
+	}
+
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+	if (substream != NULL) {
+		err = snd_pcm_oss_make_ready(substream);
+		if (err < 0)
+			return err;
+		runtime = substream->runtime;
+		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
+		if (err < 0)
+			return err;
+		mutex_lock(&runtime->oss.params_lock);
+		runtime->oss.buffer_used = 0;
+		runtime->oss.prepare = 1;
+		mutex_unlock(&runtime->oss.params_lock);
+	}
+	return 0;
+}
+
+static int snd_pcm_oss_set_rate(struct snd_pcm_oss_file *pcm_oss_file, int rate)
+{
+	int idx;
+
+	for (idx = 1; idx >= 0; --idx) {
+		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		struct snd_pcm_runtime *runtime;
+		int err;
+
+		if (substream == NULL)
+			continue;
+		runtime = substream->runtime;
+		if (rate < 1000)
+			rate = 1000;
+		else if (rate > 192000)
+			rate = 192000;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
+		if (runtime->oss.rate != rate) {
+			runtime->oss.params = 1;
+			runtime->oss.rate = rate;
+		}
+		unlock_params(runtime);
+	}
+	return snd_pcm_oss_get_rate(pcm_oss_file);
+}
+
+static int snd_pcm_oss_get_rate(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+	
+	err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream);
+	if (err < 0)
+		return err;
+	return substream->runtime->oss.rate;
+}
+
+static int snd_pcm_oss_set_channels(struct snd_pcm_oss_file *pcm_oss_file, unsigned int channels)
+{
+	int idx;
+	if (channels < 1)
+		channels = 1;
+	if (channels > 128)
+		return -EINVAL;
+	for (idx = 1; idx >= 0; --idx) {
+		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		struct snd_pcm_runtime *runtime;
+		int err;
+
+		if (substream == NULL)
+			continue;
+		runtime = substream->runtime;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
+		if (runtime->oss.channels != channels) {
+			runtime->oss.params = 1;
+			runtime->oss.channels = channels;
+		}
+		unlock_params(runtime);
+	}
+	return snd_pcm_oss_get_channels(pcm_oss_file);
+}
+
+static int snd_pcm_oss_get_channels(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+	
+	err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream);
+	if (err < 0)
+		return err;
+	return substream->runtime->oss.channels;
+}
+
+static int snd_pcm_oss_get_block_size(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+	
+	err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream);
+	if (err < 0)
+		return err;
+	return substream->runtime->oss.period_bytes;
+}
+
+static int snd_pcm_oss_get_formats(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+	int direct;
+	struct snd_pcm_hw_params *params;
+	unsigned int formats = 0;
+	const struct snd_mask *format_mask;
+	int fmt;
+
+	err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream);
+	if (err < 0)
+		return err;
+	if (atomic_read(&substream->mmap_count))
+		direct = 1;
+	else
+		direct = substream->oss.setup.direct;
+	if (!direct)
+		return AFMT_MU_LAW | AFMT_U8 |
+		       AFMT_S16_LE | AFMT_S16_BE |
+		       AFMT_S8 | AFMT_U16_LE |
+		       AFMT_U16_BE |
+			AFMT_S32_LE | AFMT_S32_BE |
+			AFMT_S24_LE | AFMT_S24_BE |
+			AFMT_S24_PACKED;
+	params = kmalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+	_snd_pcm_hw_params_any(params);
+	err = snd_pcm_hw_refine(substream, params);
+	if (err < 0)
+		goto error;
+	format_mask = hw_param_mask_c(params, SNDRV_PCM_HW_PARAM_FORMAT);
+	for (fmt = 0; fmt < 32; ++fmt) {
+		if (snd_mask_test(format_mask, fmt)) {
+			int f = snd_pcm_oss_format_to((__force snd_pcm_format_t)fmt);
+			if (f >= 0)
+				formats |= f;
+		}
+	}
+
+ error:
+	kfree(params);
+	return err < 0 ? err : formats;
+}
+
+static int snd_pcm_oss_set_format(struct snd_pcm_oss_file *pcm_oss_file, int format)
+{
+	int formats, idx;
+	int err;
+	
+	if (format != AFMT_QUERY) {
+		formats = snd_pcm_oss_get_formats(pcm_oss_file);
+		if (formats < 0)
+			return formats;
+		if (!(formats & format))
+			format = AFMT_U8;
+		for (idx = 1; idx >= 0; --idx) {
+			struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+			struct snd_pcm_runtime *runtime;
+			if (substream == NULL)
+				continue;
+			runtime = substream->runtime;
+			err = lock_params(runtime);
+			if (err < 0)
+				return err;
+			if (runtime->oss.format != format) {
+				runtime->oss.params = 1;
+				runtime->oss.format = format;
+			}
+			unlock_params(runtime);
+		}
+	}
+	return snd_pcm_oss_get_format(pcm_oss_file);
+}
+
+static int snd_pcm_oss_get_format(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+	
+	err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream);
+	if (err < 0)
+		return err;
+	return substream->runtime->oss.format;
+}
+
+static int snd_pcm_oss_set_subdivide1(struct snd_pcm_substream *substream, int subdivide)
+{
+	struct snd_pcm_runtime *runtime;
+
+	runtime = substream->runtime;
+	if (subdivide == 0) {
+		subdivide = runtime->oss.subdivision;
+		if (subdivide == 0)
+			subdivide = 1;
+		return subdivide;
+	}
+	if (runtime->oss.subdivision || runtime->oss.fragshift)
+		return -EINVAL;
+	if (subdivide != 1 && subdivide != 2 && subdivide != 4 &&
+	    subdivide != 8 && subdivide != 16)
+		return -EINVAL;
+	runtime->oss.subdivision = subdivide;
+	runtime->oss.params = 1;
+	return subdivide;
+}
+
+static int snd_pcm_oss_set_subdivide(struct snd_pcm_oss_file *pcm_oss_file, int subdivide)
+{
+	int err = -EINVAL, idx;
+
+	for (idx = 1; idx >= 0; --idx) {
+		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		struct snd_pcm_runtime *runtime;
+
+		if (substream == NULL)
+			continue;
+		runtime = substream->runtime;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
+		err = snd_pcm_oss_set_subdivide1(substream, subdivide);
+		unlock_params(runtime);
+		if (err < 0)
+			return err;
+	}
+	return err;
+}
+
+static int snd_pcm_oss_set_fragment1(struct snd_pcm_substream *substream, unsigned int val)
+{
+	struct snd_pcm_runtime *runtime;
+	int fragshift;
+
+	runtime = substream->runtime;
+	if (runtime->oss.subdivision || runtime->oss.fragshift)
+		return -EINVAL;
+	fragshift = val & 0xffff;
+	if (fragshift >= 25) /* should be large enough */
+		return -EINVAL;
+	runtime->oss.fragshift = fragshift;
+	runtime->oss.maxfrags = (val >> 16) & 0xffff;
+	if (runtime->oss.fragshift < 4)		/* < 16 */
+		runtime->oss.fragshift = 4;
+	if (runtime->oss.maxfrags < 2)
+		runtime->oss.maxfrags = 2;
+	runtime->oss.params = 1;
+	return 0;
+}
+
+static int snd_pcm_oss_set_fragment(struct snd_pcm_oss_file *pcm_oss_file, unsigned int val)
+{
+	int err = -EINVAL, idx;
+
+	for (idx = 1; idx >= 0; --idx) {
+		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		struct snd_pcm_runtime *runtime;
+
+		if (substream == NULL)
+			continue;
+		runtime = substream->runtime;
+		err = lock_params(runtime);
+		if (err < 0)
+			return err;
+		err = snd_pcm_oss_set_fragment1(substream, val);
+		unlock_params(runtime);
+		if (err < 0)
+			return err;
+	}
+	return err;
+}
+
+static int snd_pcm_oss_nonblock(struct file * file)
+{
+	spin_lock(&file->f_lock);
+	file->f_flags |= O_NONBLOCK;
+	spin_unlock(&file->f_lock);
+	return 0;
+}
+
+static int snd_pcm_oss_get_caps1(struct snd_pcm_substream *substream, int res)
+{
+
+	if (substream == NULL) {
+		res &= ~DSP_CAP_DUPLEX;
+		return res;
+	}
+#ifdef DSP_CAP_MULTI
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		if (substream->pstr->substream_count > 1)
+			res |= DSP_CAP_MULTI;
+#endif
+	/* DSP_CAP_REALTIME is set all times: */
+	/* all ALSA drivers can return actual pointer in ring buffer */
+#if defined(DSP_CAP_REALTIME) && 0
+	{
+		struct snd_pcm_runtime *runtime = substream->runtime;
+		if (runtime->info & (SNDRV_PCM_INFO_BLOCK_TRANSFER|SNDRV_PCM_INFO_BATCH))
+			res &= ~DSP_CAP_REALTIME;
+	}
+#endif
+	return res;
+}
+
+static int snd_pcm_oss_get_caps(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	int result, idx;
+	
+	result = DSP_CAP_TRIGGER | DSP_CAP_MMAP	| DSP_CAP_DUPLEX | DSP_CAP_REALTIME;
+	for (idx = 0; idx < 2; idx++) {
+		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
+		result = snd_pcm_oss_get_caps1(substream, result);
+	}
+	result |= 0x0001;	/* revision - same as SB AWE 64 */
+	return result;
+}
+
+static void snd_pcm_oss_simulate_fill(struct snd_pcm_substream *substream,
+				      snd_pcm_uframes_t hw_ptr)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t appl_ptr;
+	appl_ptr = hw_ptr + runtime->buffer_size;
+	appl_ptr %= runtime->boundary;
+	runtime->control->appl_ptr = appl_ptr;
+}
+
+static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int trigger)
+{
+	struct snd_pcm_runtime *runtime;
+	struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
+	int err, cmd;
+
+#ifdef OSS_DEBUG
+	pr_debug("pcm_oss: trigger = 0x%x\n", trigger);
+#endif
+	
+	psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+
+	if (psubstream) {
+		err = snd_pcm_oss_make_ready(psubstream);
+		if (err < 0)
+			return err;
+	}
+	if (csubstream) {
+		err = snd_pcm_oss_make_ready(csubstream);
+		if (err < 0)
+			return err;
+	}
+      	if (psubstream) {
+      		runtime = psubstream->runtime;
+		cmd = 0;
+		if (mutex_lock_interruptible(&runtime->oss.params_lock))
+			return -ERESTARTSYS;
+		if (trigger & PCM_ENABLE_OUTPUT) {
+			if (runtime->oss.trigger)
+				goto _skip1;
+			if (atomic_read(&psubstream->mmap_count))
+				snd_pcm_oss_simulate_fill(psubstream,
+						get_hw_ptr_period(runtime));
+			runtime->oss.trigger = 1;
+			runtime->start_threshold = 1;
+			cmd = SNDRV_PCM_IOCTL_START;
+		} else {
+			if (!runtime->oss.trigger)
+				goto _skip1;
+			runtime->oss.trigger = 0;
+			runtime->start_threshold = runtime->boundary;
+			cmd = SNDRV_PCM_IOCTL_DROP;
+			runtime->oss.prepare = 1;
+		}
+ _skip1:
+		mutex_unlock(&runtime->oss.params_lock);
+		if (cmd) {
+			err = snd_pcm_kernel_ioctl(psubstream, cmd, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
+	if (csubstream) {
+      		runtime = csubstream->runtime;
+		cmd = 0;
+		if (mutex_lock_interruptible(&runtime->oss.params_lock))
+			return -ERESTARTSYS;
+		if (trigger & PCM_ENABLE_INPUT) {
+			if (runtime->oss.trigger)
+				goto _skip2;
+			runtime->oss.trigger = 1;
+			runtime->start_threshold = 1;
+			cmd = SNDRV_PCM_IOCTL_START;
+		} else {
+			if (!runtime->oss.trigger)
+				goto _skip2;
+			runtime->oss.trigger = 0;
+			runtime->start_threshold = runtime->boundary;
+			cmd = SNDRV_PCM_IOCTL_DROP;
+			runtime->oss.prepare = 1;
+		}
+ _skip2:
+		mutex_unlock(&runtime->oss.params_lock);
+		if (cmd) {
+			err = snd_pcm_kernel_ioctl(csubstream, cmd, NULL);
+			if (err < 0)
+				return err;
+		}
+	}
+	return 0;
+}
+
+static int snd_pcm_oss_get_trigger(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
+	int result = 0;
+
+	psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+	if (psubstream && psubstream->runtime && psubstream->runtime->oss.trigger)
+		result |= PCM_ENABLE_OUTPUT;
+	if (csubstream && csubstream->runtime && csubstream->runtime->oss.trigger)
+		result |= PCM_ENABLE_INPUT;
+	return result;
+}
+
+static int snd_pcm_oss_get_odelay(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t delay;
+	int err;
+
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	if (substream == NULL)
+		return -EINVAL;
+	err = snd_pcm_oss_make_ready(substream);
+	if (err < 0)
+		return err;
+	runtime = substream->runtime;
+	if (runtime->oss.params || runtime->oss.prepare)
+		return 0;
+	err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
+	if (err == -EPIPE)
+		delay = 0;	/* hack for broken OSS applications */
+	else if (err < 0)
+		return err;
+	return snd_pcm_oss_bytes(substream, delay);
+}
+
+static int snd_pcm_oss_get_ptr(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct count_info __user * _info)
+{	
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t delay;
+	int fixup;
+	struct count_info info;
+	int err;
+
+	if (_info == NULL)
+		return -EFAULT;
+	substream = pcm_oss_file->streams[stream];
+	if (substream == NULL)
+		return -EINVAL;
+	err = snd_pcm_oss_make_ready(substream);
+	if (err < 0)
+		return err;
+	runtime = substream->runtime;
+	if (runtime->oss.params || runtime->oss.prepare) {
+		memset(&info, 0, sizeof(info));
+		if (copy_to_user(_info, &info, sizeof(info)))
+			return -EFAULT;
+		return 0;
+	}
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
+		if (err == -EPIPE || err == -ESTRPIPE || (! err && delay < 0)) {
+			err = 0;
+			delay = 0;
+			fixup = 0;
+		} else {
+			fixup = runtime->oss.buffer_used;
+		}
+	} else {
+		err = snd_pcm_oss_capture_position_fixup(substream, &delay);
+		fixup = -runtime->oss.buffer_used;
+	}
+	if (err < 0)
+		return err;
+	info.ptr = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr % runtime->buffer_size);
+	if (atomic_read(&substream->mmap_count)) {
+		snd_pcm_sframes_t n;
+		delay = get_hw_ptr_period(runtime);
+		n = delay - runtime->oss.prev_hw_ptr_period;
+		if (n < 0)
+			n += runtime->boundary;
+		info.blocks = n / runtime->period_size;
+		runtime->oss.prev_hw_ptr_period = delay;
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			snd_pcm_oss_simulate_fill(substream, delay);
+		info.bytes = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr) & INT_MAX;
+	} else {
+		delay = snd_pcm_oss_bytes(substream, delay);
+		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			if (substream->oss.setup.buggyptr)
+				info.blocks = (runtime->oss.buffer_bytes - delay - fixup) / runtime->oss.period_bytes;
+			else
+				info.blocks = (delay + fixup) / runtime->oss.period_bytes;
+			info.bytes = (runtime->oss.bytes - delay) & INT_MAX;
+		} else {
+			delay += fixup;
+			info.blocks = delay / runtime->oss.period_bytes;
+			info.bytes = (runtime->oss.bytes + delay) & INT_MAX;
+		}
+	}
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_pcm_oss_get_space(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct audio_buf_info __user *_info)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t avail;
+	int fixup;
+	struct audio_buf_info info;
+	int err;
+
+	if (_info == NULL)
+		return -EFAULT;
+	substream = pcm_oss_file->streams[stream];
+	if (substream == NULL)
+		return -EINVAL;
+	runtime = substream->runtime;
+
+	if (runtime->oss.params) {
+		err = snd_pcm_oss_change_params(substream, false);
+		if (err < 0)
+			return err;
+	}
+
+	info.fragsize = runtime->oss.period_bytes;
+	info.fragstotal = runtime->periods;
+	if (runtime->oss.prepare) {
+		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			info.bytes = runtime->oss.period_bytes * runtime->oss.periods;
+			info.fragments = runtime->oss.periods;
+		} else {
+			info.bytes = 0;
+			info.fragments = 0;
+		}
+	} else {
+		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &avail);
+			if (err == -EPIPE || err == -ESTRPIPE || (! err && avail < 0)) {
+				avail = runtime->buffer_size;
+				err = 0;
+				fixup = 0;
+			} else {
+				avail = runtime->buffer_size - avail;
+				fixup = -runtime->oss.buffer_used;
+			}
+		} else {
+			err = snd_pcm_oss_capture_position_fixup(substream, &avail);
+			fixup = runtime->oss.buffer_used;
+		}
+		if (err < 0)
+			return err;
+		info.bytes = snd_pcm_oss_bytes(substream, avail) + fixup;
+		info.fragments = info.bytes / runtime->oss.period_bytes;
+	}
+
+#ifdef OSS_DEBUG
+	pcm_dbg(substream->pcm,
+		"pcm_oss: space: bytes = %i, fragments = %i, fragstotal = %i, fragsize = %i\n",
+		info.bytes, info.fragments, info.fragstotal, info.fragsize);
+#endif
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_pcm_oss_get_mapbuf(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct buffmem_desc __user * _info)
+{
+	// it won't be probably implemented
+	// pr_debug("TODO: snd_pcm_oss_get_mapbuf\n");
+	return -EINVAL;
+}
+
+static const char *strip_task_path(const char *path)
+{
+	const char *ptr, *ptrl = NULL;
+	for (ptr = path; *ptr; ptr++) {
+		if (*ptr == '/')
+			ptrl = ptr + 1;
+	}
+	return ptrl;
+}
+
+static void snd_pcm_oss_look_for_setup(struct snd_pcm *pcm, int stream,
+				      const char *task_name,
+				      struct snd_pcm_oss_setup *rsetup)
+{
+	struct snd_pcm_oss_setup *setup;
+
+	mutex_lock(&pcm->streams[stream].oss.setup_mutex);
+	do {
+		for (setup = pcm->streams[stream].oss.setup_list; setup;
+		     setup = setup->next) {
+			if (!strcmp(setup->task_name, task_name))
+				goto out;
+		}
+	} while ((task_name = strip_task_path(task_name)) != NULL);
+ out:
+	if (setup)
+		*rsetup = *setup;
+	mutex_unlock(&pcm->streams[stream].oss.setup_mutex);
+}
+
+static void snd_pcm_oss_release_substream(struct snd_pcm_substream *substream)
+{
+	snd_pcm_oss_release_buffers(substream);
+	substream->oss.oss = 0;
+}
+
+static void snd_pcm_oss_init_substream(struct snd_pcm_substream *substream,
+				       struct snd_pcm_oss_setup *setup,
+				       int minor)
+{
+	struct snd_pcm_runtime *runtime;
+
+	substream->oss.oss = 1;
+	substream->oss.setup = *setup;
+	if (setup->nonblock)
+		substream->f_flags |= O_NONBLOCK;
+	else if (setup->block)
+		substream->f_flags &= ~O_NONBLOCK;
+	runtime = substream->runtime;
+	runtime->oss.params = 1;
+	runtime->oss.trigger = 1;
+	runtime->oss.rate = 8000;
+	mutex_init(&runtime->oss.params_lock);
+	switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
+	case SNDRV_MINOR_OSS_PCM_8:
+		runtime->oss.format = AFMT_U8;
+		break;
+	case SNDRV_MINOR_OSS_PCM_16:
+		runtime->oss.format = AFMT_S16_LE;
+		break;
+	default:
+		runtime->oss.format = AFMT_MU_LAW;
+	}
+	runtime->oss.channels = 1;
+	runtime->oss.fragshift = 0;
+	runtime->oss.maxfrags = 0;
+	runtime->oss.subdivision = 0;
+	substream->pcm_release = snd_pcm_oss_release_substream;
+	atomic_set(&runtime->oss.rw_ref, 0);
+}
+
+static int snd_pcm_oss_release_file(struct snd_pcm_oss_file *pcm_oss_file)
+{
+	int cidx;
+	if (!pcm_oss_file)
+		return 0;
+	for (cidx = 0; cidx < 2; ++cidx) {
+		struct snd_pcm_substream *substream = pcm_oss_file->streams[cidx];
+		if (substream)
+			snd_pcm_release_substream(substream);
+	}
+	kfree(pcm_oss_file);
+	return 0;
+}
+
+static int snd_pcm_oss_open_file(struct file *file,
+				 struct snd_pcm *pcm,
+				 struct snd_pcm_oss_file **rpcm_oss_file,
+				 int minor,
+				 struct snd_pcm_oss_setup *setup)
+{
+	int idx, err;
+	struct snd_pcm_oss_file *pcm_oss_file;
+	struct snd_pcm_substream *substream;
+	fmode_t f_mode = file->f_mode;
+
+	if (rpcm_oss_file)
+		*rpcm_oss_file = NULL;
+
+	pcm_oss_file = kzalloc(sizeof(*pcm_oss_file), GFP_KERNEL);
+	if (pcm_oss_file == NULL)
+		return -ENOMEM;
+
+	if ((f_mode & (FMODE_WRITE|FMODE_READ)) == (FMODE_WRITE|FMODE_READ) &&
+	    (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX))
+		f_mode = FMODE_WRITE;
+
+	file->f_flags &= ~O_APPEND;
+	for (idx = 0; idx < 2; idx++) {
+		if (setup[idx].disable)
+			continue;
+		if (! pcm->streams[idx].substream_count)
+			continue; /* no matching substream */
+		if (idx == SNDRV_PCM_STREAM_PLAYBACK) {
+			if (! (f_mode & FMODE_WRITE))
+				continue;
+		} else {
+			if (! (f_mode & FMODE_READ))
+				continue;
+		}
+		err = snd_pcm_open_substream(pcm, idx, file, &substream);
+		if (err < 0) {
+			snd_pcm_oss_release_file(pcm_oss_file);
+			return err;
+		}
+
+		pcm_oss_file->streams[idx] = substream;
+		snd_pcm_oss_init_substream(substream, &setup[idx], minor);
+	}
+	
+	if (!pcm_oss_file->streams[0] && !pcm_oss_file->streams[1]) {
+		snd_pcm_oss_release_file(pcm_oss_file);
+		return -EINVAL;
+	}
+
+	file->private_data = pcm_oss_file;
+	if (rpcm_oss_file)
+		*rpcm_oss_file = pcm_oss_file;
+	return 0;
+}
+
+
+static int snd_task_name(struct task_struct *task, char *name, size_t size)
+{
+	unsigned int idx;
+
+	if (snd_BUG_ON(!task || !name || size < 2))
+		return -EINVAL;
+	for (idx = 0; idx < sizeof(task->comm) && idx + 1 < size; idx++)
+		name[idx] = task->comm[idx];
+	name[idx] = '\0';
+	return 0;
+}
+
+static int snd_pcm_oss_open(struct inode *inode, struct file *file)
+{
+	int err;
+	char task_name[32];
+	struct snd_pcm *pcm;
+	struct snd_pcm_oss_file *pcm_oss_file;
+	struct snd_pcm_oss_setup setup[2];
+	int nonblock;
+	wait_queue_entry_t wait;
+
+	err = nonseekable_open(inode, file);
+	if (err < 0)
+		return err;
+
+	pcm = snd_lookup_oss_minor_data(iminor(inode),
+					SNDRV_OSS_DEVICE_TYPE_PCM);
+	if (pcm == NULL) {
+		err = -ENODEV;
+		goto __error1;
+	}
+	err = snd_card_file_add(pcm->card, file);
+	if (err < 0)
+		goto __error1;
+	if (!try_module_get(pcm->card->module)) {
+		err = -EFAULT;
+		goto __error2;
+	}
+	if (snd_task_name(current, task_name, sizeof(task_name)) < 0) {
+		err = -EFAULT;
+		goto __error;
+	}
+	memset(setup, 0, sizeof(setup));
+	if (file->f_mode & FMODE_WRITE)
+		snd_pcm_oss_look_for_setup(pcm, SNDRV_PCM_STREAM_PLAYBACK,
+					   task_name, &setup[0]);
+	if (file->f_mode & FMODE_READ)
+		snd_pcm_oss_look_for_setup(pcm, SNDRV_PCM_STREAM_CAPTURE,
+					   task_name, &setup[1]);
+
+	nonblock = !!(file->f_flags & O_NONBLOCK);
+	if (!nonblock)
+		nonblock = nonblock_open;
+
+	init_waitqueue_entry(&wait, current);
+	add_wait_queue(&pcm->open_wait, &wait);
+	mutex_lock(&pcm->open_mutex);
+	while (1) {
+		err = snd_pcm_oss_open_file(file, pcm, &pcm_oss_file,
+					    iminor(inode), setup);
+		if (err >= 0)
+			break;
+		if (err == -EAGAIN) {
+			if (nonblock) {
+				err = -EBUSY;
+				break;
+			}
+		} else
+			break;
+		set_current_state(TASK_INTERRUPTIBLE);
+		mutex_unlock(&pcm->open_mutex);
+		schedule();
+		mutex_lock(&pcm->open_mutex);
+		if (pcm->card->shutdown) {
+			err = -ENODEV;
+			break;
+		}
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+	}
+	remove_wait_queue(&pcm->open_wait, &wait);
+	mutex_unlock(&pcm->open_mutex);
+	if (err < 0)
+		goto __error;
+	snd_card_unref(pcm->card);
+	return err;
+
+      __error:
+     	module_put(pcm->card->module);
+      __error2:
+      	snd_card_file_remove(pcm->card, file);
+      __error1:
+	if (pcm)
+		snd_card_unref(pcm->card);
+	return err;
+}
+
+static int snd_pcm_oss_release(struct inode *inode, struct file *file)
+{
+	struct snd_pcm *pcm;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_oss_file *pcm_oss_file;
+
+	pcm_oss_file = file->private_data;
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	if (substream == NULL)
+		substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+	if (snd_BUG_ON(!substream))
+		return -ENXIO;
+	pcm = substream->pcm;
+	if (!pcm->card->shutdown)
+		snd_pcm_oss_sync(pcm_oss_file);
+	mutex_lock(&pcm->open_mutex);
+	snd_pcm_oss_release_file(pcm_oss_file);
+	mutex_unlock(&pcm->open_mutex);
+	wake_up(&pcm->open_wait);
+	module_put(pcm->card->module);
+	snd_card_file_remove(pcm->card, file);
+	return 0;
+}
+
+static long snd_pcm_oss_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_pcm_oss_file *pcm_oss_file;
+	int __user *p = (int __user *)arg;
+	int res;
+
+	pcm_oss_file = file->private_data;
+	if (cmd == OSS_GETVERSION)
+		return put_user(SNDRV_OSS_VERSION, p);
+	if (cmd == OSS_ALSAEMULVER)
+		return put_user(1, p);
+#if IS_REACHABLE(CONFIG_SND_MIXER_OSS)
+	if (((cmd >> 8) & 0xff) == 'M')	{	/* mixer ioctl - for OSS compatibility */
+		struct snd_pcm_substream *substream;
+		int idx;
+		for (idx = 0; idx < 2; ++idx) {
+			substream = pcm_oss_file->streams[idx];
+			if (substream != NULL)
+				break;
+		}
+		if (snd_BUG_ON(idx >= 2))
+			return -ENXIO;
+		return snd_mixer_oss_ioctl_card(substream->pcm->card, cmd, arg);
+	}
+#endif
+	if (((cmd >> 8) & 0xff) != 'P')
+		return -EINVAL;
+#ifdef OSS_DEBUG
+	pr_debug("pcm_oss: ioctl = 0x%x\n", cmd);
+#endif
+	switch (cmd) {
+	case SNDCTL_DSP_RESET:
+		return snd_pcm_oss_reset(pcm_oss_file);
+	case SNDCTL_DSP_SYNC:
+		return snd_pcm_oss_sync(pcm_oss_file);
+	case SNDCTL_DSP_SPEED:
+		if (get_user(res, p))
+			return -EFAULT;
+		res = snd_pcm_oss_set_rate(pcm_oss_file, res);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SOUND_PCM_READ_RATE:
+		res = snd_pcm_oss_get_rate(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_STEREO:
+		if (get_user(res, p))
+			return -EFAULT;
+		res = res > 0 ? 2 : 1;
+		res = snd_pcm_oss_set_channels(pcm_oss_file, res);
+		if (res < 0)
+			return res;
+		return put_user(--res, p);
+	case SNDCTL_DSP_GETBLKSIZE:
+		res = snd_pcm_oss_get_block_size(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_SETFMT:
+		if (get_user(res, p))
+			return -EFAULT;
+		res = snd_pcm_oss_set_format(pcm_oss_file, res);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SOUND_PCM_READ_BITS:
+		res = snd_pcm_oss_get_format(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_CHANNELS:
+		if (get_user(res, p))
+			return -EFAULT;
+		res = snd_pcm_oss_set_channels(pcm_oss_file, res);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SOUND_PCM_READ_CHANNELS:
+		res = snd_pcm_oss_get_channels(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SOUND_PCM_WRITE_FILTER:
+	case SOUND_PCM_READ_FILTER:
+		return -EIO;
+	case SNDCTL_DSP_POST:
+		return snd_pcm_oss_post(pcm_oss_file);
+	case SNDCTL_DSP_SUBDIVIDE:
+		if (get_user(res, p))
+			return -EFAULT;
+		res = snd_pcm_oss_set_subdivide(pcm_oss_file, res);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_SETFRAGMENT:
+		if (get_user(res, p))
+			return -EFAULT;
+		return snd_pcm_oss_set_fragment(pcm_oss_file, res);
+	case SNDCTL_DSP_GETFMTS:
+		res = snd_pcm_oss_get_formats(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_GETOSPACE:
+	case SNDCTL_DSP_GETISPACE:
+		return snd_pcm_oss_get_space(pcm_oss_file,
+			cmd == SNDCTL_DSP_GETISPACE ?
+				SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK,
+			(struct audio_buf_info __user *) arg);
+	case SNDCTL_DSP_NONBLOCK:
+		return snd_pcm_oss_nonblock(file);
+	case SNDCTL_DSP_GETCAPS:
+		res = snd_pcm_oss_get_caps(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_GETTRIGGER:
+		res = snd_pcm_oss_get_trigger(pcm_oss_file);
+		if (res < 0)
+			return res;
+		return put_user(res, p);
+	case SNDCTL_DSP_SETTRIGGER:
+		if (get_user(res, p))
+			return -EFAULT;
+		return snd_pcm_oss_set_trigger(pcm_oss_file, res);
+	case SNDCTL_DSP_GETIPTR:
+	case SNDCTL_DSP_GETOPTR:
+		return snd_pcm_oss_get_ptr(pcm_oss_file,
+			cmd == SNDCTL_DSP_GETIPTR ?
+				SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK,
+			(struct count_info __user *) arg);
+	case SNDCTL_DSP_MAPINBUF:
+	case SNDCTL_DSP_MAPOUTBUF:
+		return snd_pcm_oss_get_mapbuf(pcm_oss_file,
+			cmd == SNDCTL_DSP_MAPINBUF ?
+				SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK,
+			(struct buffmem_desc __user *) arg);
+	case SNDCTL_DSP_SETSYNCRO:
+		/* stop DMA now.. */
+		return 0;
+	case SNDCTL_DSP_SETDUPLEX:
+		if (snd_pcm_oss_get_caps(pcm_oss_file) & DSP_CAP_DUPLEX)
+			return 0;
+		return -EIO;
+	case SNDCTL_DSP_GETODELAY:
+		res = snd_pcm_oss_get_odelay(pcm_oss_file);
+		if (res < 0) {
+			/* it's for sure, some broken apps don't check for error codes */
+			put_user(0, p);
+			return res;
+		}
+		return put_user(res, p);
+	case SNDCTL_DSP_PROFILE:
+		return 0;	/* silently ignore */
+	default:
+		pr_debug("pcm_oss: unknown command = 0x%x\n", cmd);
+	}
+	return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+/* all compatible */
+static long snd_pcm_oss_ioctl_compat(struct file *file, unsigned int cmd,
+				     unsigned long arg)
+{
+	/*
+	 * Everything is compatbile except SNDCTL_DSP_MAPINBUF/SNDCTL_DSP_MAPOUTBUF,
+	 * which are not implemented for the native case either
+	 */
+	return snd_pcm_oss_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#else
+#define snd_pcm_oss_ioctl_compat	NULL
+#endif
+
+static ssize_t snd_pcm_oss_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
+{
+	struct snd_pcm_oss_file *pcm_oss_file;
+	struct snd_pcm_substream *substream;
+
+	pcm_oss_file = file->private_data;
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+	if (substream == NULL)
+		return -ENXIO;
+	substream->f_flags = file->f_flags & O_NONBLOCK;
+#ifndef OSS_DEBUG
+	return snd_pcm_oss_read1(substream, buf, count);
+#else
+	{
+		ssize_t res = snd_pcm_oss_read1(substream, buf, count);
+		pcm_dbg(substream->pcm,
+			"pcm_oss: read %li bytes (returned %li bytes)\n",
+			(long)count, (long)res);
+		return res;
+	}
+#endif
+}
+
+static ssize_t snd_pcm_oss_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
+{
+	struct snd_pcm_oss_file *pcm_oss_file;
+	struct snd_pcm_substream *substream;
+	long result;
+
+	pcm_oss_file = file->private_data;
+	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	if (substream == NULL)
+		return -ENXIO;
+	substream->f_flags = file->f_flags & O_NONBLOCK;
+	result = snd_pcm_oss_write1(substream, buf, count);
+#ifdef OSS_DEBUG
+	pcm_dbg(substream->pcm, "pcm_oss: write %li bytes (wrote %li bytes)\n",
+	       (long)count, (long)result);
+#endif
+	return result;
+}
+
+static int snd_pcm_oss_playback_ready(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (atomic_read(&substream->mmap_count))
+		return runtime->oss.prev_hw_ptr_period !=
+						get_hw_ptr_period(runtime);
+	else
+		return snd_pcm_playback_avail(runtime) >=
+						runtime->oss.period_frames;
+}
+
+static int snd_pcm_oss_capture_ready(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (atomic_read(&substream->mmap_count))
+		return runtime->oss.prev_hw_ptr_period !=
+						get_hw_ptr_period(runtime);
+	else
+		return snd_pcm_capture_avail(runtime) >=
+						runtime->oss.period_frames;
+}
+
+static __poll_t snd_pcm_oss_poll(struct file *file, poll_table * wait)
+{
+	struct snd_pcm_oss_file *pcm_oss_file;
+	__poll_t mask;
+	struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
+	
+	pcm_oss_file = file->private_data;
+
+	psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+	csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+
+	mask = 0;
+	if (psubstream != NULL) {
+		struct snd_pcm_runtime *runtime = psubstream->runtime;
+		poll_wait(file, &runtime->sleep, wait);
+		snd_pcm_stream_lock_irq(psubstream);
+		if (runtime->state != SNDRV_PCM_STATE_DRAINING &&
+		    (runtime->state != SNDRV_PCM_STATE_RUNNING ||
+		     snd_pcm_oss_playback_ready(psubstream)))
+			mask |= EPOLLOUT | EPOLLWRNORM;
+		snd_pcm_stream_unlock_irq(psubstream);
+	}
+	if (csubstream != NULL) {
+		struct snd_pcm_runtime *runtime = csubstream->runtime;
+		snd_pcm_state_t ostate;
+		poll_wait(file, &runtime->sleep, wait);
+		snd_pcm_stream_lock_irq(csubstream);
+		ostate = runtime->state;
+		if (ostate != SNDRV_PCM_STATE_RUNNING ||
+		    snd_pcm_oss_capture_ready(csubstream))
+			mask |= EPOLLIN | EPOLLRDNORM;
+		snd_pcm_stream_unlock_irq(csubstream);
+		if (ostate != SNDRV_PCM_STATE_RUNNING && runtime->oss.trigger) {
+			struct snd_pcm_oss_file ofile;
+			memset(&ofile, 0, sizeof(ofile));
+			ofile.streams[SNDRV_PCM_STREAM_CAPTURE] = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+			runtime->oss.trigger = 0;
+			snd_pcm_oss_set_trigger(&ofile, PCM_ENABLE_INPUT);
+		}
+	}
+
+	return mask;
+}
+
+static int snd_pcm_oss_mmap(struct file *file, struct vm_area_struct *area)
+{
+	struct snd_pcm_oss_file *pcm_oss_file;
+	struct snd_pcm_substream *substream = NULL;
+	struct snd_pcm_runtime *runtime;
+	int err;
+
+#ifdef OSS_DEBUG
+	pr_debug("pcm_oss: mmap begin\n");
+#endif
+	pcm_oss_file = file->private_data;
+	switch ((area->vm_flags & (VM_READ | VM_WRITE))) {
+	case VM_READ | VM_WRITE:
+		substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+		if (substream)
+			break;
+		fallthrough;
+	case VM_READ:
+		substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
+		break;
+	case VM_WRITE:
+		substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
+		break;
+	default:
+		return -EINVAL;
+	}
+	/* set VM_READ access as well to fix memset() routines that do
+	   reads before writes (to improve performance) */
+	vm_flags_set(area, VM_READ);
+	if (substream == NULL)
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (!(runtime->info & SNDRV_PCM_INFO_MMAP_VALID))
+		return -EIO;
+	if (runtime->info & SNDRV_PCM_INFO_INTERLEAVED)
+		runtime->access = SNDRV_PCM_ACCESS_MMAP_INTERLEAVED;
+	else
+		return -EIO;
+	
+	if (runtime->oss.params) {
+		/* use mutex_trylock() for params_lock for avoiding a deadlock
+		 * between mmap_lock and params_lock taken by
+		 * copy_from/to_user() in snd_pcm_oss_write/read()
+		 */
+		err = snd_pcm_oss_change_params(substream, true);
+		if (err < 0)
+			return err;
+	}
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+	if (runtime->oss.plugin_first != NULL)
+		return -EIO;
+#endif
+
+	if (area->vm_pgoff != 0)
+		return -EINVAL;
+
+	err = snd_pcm_mmap_data(substream, file, area);
+	if (err < 0)
+		return err;
+	runtime->oss.mmap_bytes = area->vm_end - area->vm_start;
+	runtime->silence_threshold = 0;
+	runtime->silence_size = 0;
+#ifdef OSS_DEBUG
+	pr_debug("pcm_oss: mmap ok, bytes = 0x%x\n",
+	       runtime->oss.mmap_bytes);
+#endif
+	/* In mmap mode we never stop */
+	runtime->stop_threshold = runtime->boundary;
+
+	return 0;
+}
+
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+/*
+ *  /proc interface
+ */
+
+static void snd_pcm_oss_proc_read(struct snd_info_entry *entry,
+				  struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_str *pstr = entry->private_data;
+	struct snd_pcm_oss_setup *setup = pstr->oss.setup_list;
+	mutex_lock(&pstr->oss.setup_mutex);
+	while (setup) {
+		snd_iprintf(buffer, "%s %u %u%s%s%s%s%s%s\n",
+			    setup->task_name,
+			    setup->periods,
+			    setup->period_size,
+			    setup->disable ? " disable" : "",
+			    setup->direct ? " direct" : "",
+			    setup->block ? " block" : "",
+			    setup->nonblock ? " non-block" : "",
+			    setup->partialfrag ? " partial-frag" : "",
+			    setup->nosilence ? " no-silence" : "");
+		setup = setup->next;
+	}
+	mutex_unlock(&pstr->oss.setup_mutex);
+}
+
+static void snd_pcm_oss_proc_free_setup_list(struct snd_pcm_str * pstr)
+{
+	struct snd_pcm_oss_setup *setup, *setupn;
+
+	for (setup = pstr->oss.setup_list, pstr->oss.setup_list = NULL;
+	     setup; setup = setupn) {
+		setupn = setup->next;
+		kfree(setup->task_name);
+		kfree(setup);
+	}
+	pstr->oss.setup_list = NULL;
+}
+
+static void snd_pcm_oss_proc_write(struct snd_info_entry *entry,
+				   struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_str *pstr = entry->private_data;
+	char line[128], str[32], task_name[32];
+	const char *ptr;
+	int idx1;
+	struct snd_pcm_oss_setup *setup, *setup1, template;
+
+	while (!snd_info_get_line(buffer, line, sizeof(line))) {
+		mutex_lock(&pstr->oss.setup_mutex);
+		memset(&template, 0, sizeof(template));
+		ptr = snd_info_get_str(task_name, line, sizeof(task_name));
+		if (!strcmp(task_name, "clear") || !strcmp(task_name, "erase")) {
+			snd_pcm_oss_proc_free_setup_list(pstr);
+			mutex_unlock(&pstr->oss.setup_mutex);
+			continue;
+		}
+		for (setup = pstr->oss.setup_list; setup; setup = setup->next) {
+			if (!strcmp(setup->task_name, task_name)) {
+				template = *setup;
+				break;
+			}
+		}
+		ptr = snd_info_get_str(str, ptr, sizeof(str));
+		template.periods = simple_strtoul(str, NULL, 10);
+		ptr = snd_info_get_str(str, ptr, sizeof(str));
+		template.period_size = simple_strtoul(str, NULL, 10);
+		for (idx1 = 31; idx1 >= 0; idx1--)
+			if (template.period_size & (1 << idx1))
+				break;
+		for (idx1--; idx1 >= 0; idx1--)
+			template.period_size &= ~(1 << idx1);
+		do {
+			ptr = snd_info_get_str(str, ptr, sizeof(str));
+			if (!strcmp(str, "disable")) {
+				template.disable = 1;
+			} else if (!strcmp(str, "direct")) {
+				template.direct = 1;
+			} else if (!strcmp(str, "block")) {
+				template.block = 1;
+			} else if (!strcmp(str, "non-block")) {
+				template.nonblock = 1;
+			} else if (!strcmp(str, "partial-frag")) {
+				template.partialfrag = 1;
+			} else if (!strcmp(str, "no-silence")) {
+				template.nosilence = 1;
+			} else if (!strcmp(str, "buggy-ptr")) {
+				template.buggyptr = 1;
+			}
+		} while (*str);
+		if (setup == NULL) {
+			setup = kmalloc(sizeof(*setup), GFP_KERNEL);
+			if (! setup) {
+				buffer->error = -ENOMEM;
+				mutex_unlock(&pstr->oss.setup_mutex);
+				return;
+			}
+			if (pstr->oss.setup_list == NULL)
+				pstr->oss.setup_list = setup;
+			else {
+				for (setup1 = pstr->oss.setup_list;
+				     setup1->next; setup1 = setup1->next);
+				setup1->next = setup;
+			}
+			template.task_name = kstrdup(task_name, GFP_KERNEL);
+			if (! template.task_name) {
+				kfree(setup);
+				buffer->error = -ENOMEM;
+				mutex_unlock(&pstr->oss.setup_mutex);
+				return;
+			}
+		}
+		*setup = template;
+		mutex_unlock(&pstr->oss.setup_mutex);
+	}
+}
+
+static void snd_pcm_oss_proc_init(struct snd_pcm *pcm)
+{
+	int stream;
+	for (stream = 0; stream < 2; ++stream) {
+		struct snd_info_entry *entry;
+		struct snd_pcm_str *pstr = &pcm->streams[stream];
+		if (pstr->substream_count == 0)
+			continue;
+		entry = snd_info_create_card_entry(pcm->card, "oss", pstr->proc_root);
+		if (entry) {
+			entry->content = SNDRV_INFO_CONTENT_TEXT;
+			entry->mode = S_IFREG | 0644;
+			entry->c.text.read = snd_pcm_oss_proc_read;
+			entry->c.text.write = snd_pcm_oss_proc_write;
+			entry->private_data = pstr;
+			if (snd_info_register(entry) < 0) {
+				snd_info_free_entry(entry);
+				entry = NULL;
+			}
+		}
+		pstr->oss.proc_entry = entry;
+	}
+}
+
+static void snd_pcm_oss_proc_done(struct snd_pcm *pcm)
+{
+	int stream;
+	for (stream = 0; stream < 2; ++stream) {
+		struct snd_pcm_str *pstr = &pcm->streams[stream];
+		snd_info_free_entry(pstr->oss.proc_entry);
+		pstr->oss.proc_entry = NULL;
+		snd_pcm_oss_proc_free_setup_list(pstr);
+	}
+}
+#else /* !CONFIG_SND_VERBOSE_PROCFS */
+static inline void snd_pcm_oss_proc_init(struct snd_pcm *pcm)
+{
+}
+static inline void snd_pcm_oss_proc_done(struct snd_pcm *pcm)
+{
+}
+#endif /* CONFIG_SND_VERBOSE_PROCFS */
+
+/*
+ *  ENTRY functions
+ */
+
+static const struct file_operations snd_pcm_oss_f_reg =
+{
+	.owner =	THIS_MODULE,
+	.read =		snd_pcm_oss_read,
+	.write =	snd_pcm_oss_write,
+	.open =		snd_pcm_oss_open,
+	.release =	snd_pcm_oss_release,
+	.llseek =	no_llseek,
+	.poll =		snd_pcm_oss_poll,
+	.unlocked_ioctl =	snd_pcm_oss_ioctl,
+	.compat_ioctl =	snd_pcm_oss_ioctl_compat,
+	.mmap =		snd_pcm_oss_mmap,
+};
+
+static void register_oss_dsp(struct snd_pcm *pcm, int index)
+{
+	if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
+				    pcm->card, index, &snd_pcm_oss_f_reg,
+				    pcm) < 0) {
+		pcm_err(pcm, "unable to register OSS PCM device %i:%i\n",
+			   pcm->card->number, pcm->device);
+	}
+}
+
+static int snd_pcm_oss_register_minor(struct snd_pcm *pcm)
+{
+	pcm->oss.reg = 0;
+	if (dsp_map[pcm->card->number] == (int)pcm->device) {
+		char name[128];
+		int duplex;
+		register_oss_dsp(pcm, 0);
+		duplex = (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count > 0 && 
+			      pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count && 
+			      !(pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX));
+		sprintf(name, "%s%s", pcm->name, duplex ? " (DUPLEX)" : "");
+#ifdef SNDRV_OSS_INFO_DEV_AUDIO
+		snd_oss_info_register(SNDRV_OSS_INFO_DEV_AUDIO,
+				      pcm->card->number,
+				      name);
+#endif
+		pcm->oss.reg++;
+		pcm->oss.reg_mask |= 1;
+	}
+	if (adsp_map[pcm->card->number] == (int)pcm->device) {
+		register_oss_dsp(pcm, 1);
+		pcm->oss.reg++;
+		pcm->oss.reg_mask |= 2;
+	}
+
+	if (pcm->oss.reg)
+		snd_pcm_oss_proc_init(pcm);
+
+	return 0;
+}
+
+static int snd_pcm_oss_disconnect_minor(struct snd_pcm *pcm)
+{
+	if (pcm->oss.reg) {
+		if (pcm->oss.reg_mask & 1) {
+			pcm->oss.reg_mask &= ~1;
+			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
+						  pcm->card, 0);
+		}
+		if (pcm->oss.reg_mask & 2) {
+			pcm->oss.reg_mask &= ~2;
+			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
+						  pcm->card, 1);
+		}
+		if (dsp_map[pcm->card->number] == (int)pcm->device) {
+#ifdef SNDRV_OSS_INFO_DEV_AUDIO
+			snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_AUDIO, pcm->card->number);
+#endif
+		}
+		pcm->oss.reg = 0;
+	}
+	return 0;
+}
+
+static int snd_pcm_oss_unregister_minor(struct snd_pcm *pcm)
+{
+	snd_pcm_oss_disconnect_minor(pcm);
+	snd_pcm_oss_proc_done(pcm);
+	return 0;
+}
+
+static struct snd_pcm_notify snd_pcm_oss_notify =
+{
+	.n_register =	snd_pcm_oss_register_minor,
+	.n_disconnect = snd_pcm_oss_disconnect_minor,
+	.n_unregister =	snd_pcm_oss_unregister_minor,
+};
+
+static int __init alsa_pcm_oss_init(void)
+{
+	int i;
+	int err;
+
+	/* check device map table */
+	for (i = 0; i < SNDRV_CARDS; i++) {
+		if (dsp_map[i] < 0 || dsp_map[i] >= SNDRV_PCM_DEVICES) {
+			pr_err("ALSA: pcm_oss: invalid dsp_map[%d] = %d\n",
+				   i, dsp_map[i]);
+			dsp_map[i] = 0;
+		}
+		if (adsp_map[i] < 0 || adsp_map[i] >= SNDRV_PCM_DEVICES) {
+			pr_err("ALSA: pcm_oss: invalid adsp_map[%d] = %d\n",
+				   i, adsp_map[i]);
+			adsp_map[i] = 1;
+		}
+	}
+	err = snd_pcm_notify(&snd_pcm_oss_notify, 0);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static void __exit alsa_pcm_oss_exit(void)
+{
+	snd_pcm_notify(&snd_pcm_oss_notify, 1);
+}
+
+module_init(alsa_pcm_oss_init)
+module_exit(alsa_pcm_oss_exit)
diff --git a/sound/core/oss/pcm_plugin.c b/sound/core/oss/pcm_plugin.c
new file mode 100644
index 0000000000..82e180c776
--- /dev/null
+++ b/sound/core/oss/pcm_plugin.c
@@ -0,0 +1,781 @@
+/*
+ *  PCM Plug-In shared (kernel/library) code
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+ *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+  
+#if 0
+#define PLUGIN_DEBUG
+#endif
+
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/vmalloc.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include "pcm_plugin.h"
+
+#define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
+#define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
+
+/*
+ *  because some cards might have rates "very close", we ignore
+ *  all "resampling" requests within +-5%
+ */
+static int rate_match(unsigned int src_rate, unsigned int dst_rate)
+{
+	unsigned int low = (src_rate * 95) / 100;
+	unsigned int high = (src_rate * 105) / 100;
+	return dst_rate >= low && dst_rate <= high;
+}
+
+static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
+{
+	struct snd_pcm_plugin_format *format;
+	ssize_t width;
+	size_t size;
+	unsigned int channel;
+	struct snd_pcm_plugin_channel *c;
+
+	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		format = &plugin->src_format;
+	} else {
+		format = &plugin->dst_format;
+	}
+	width = snd_pcm_format_physical_width(format->format);
+	if (width < 0)
+		return width;
+	size = array3_size(frames, format->channels, width);
+	/* check for too large period size once again */
+	if (size > 1024 * 1024)
+		return -ENOMEM;
+	if (snd_BUG_ON(size % 8))
+		return -ENXIO;
+	size /= 8;
+	if (plugin->buf_frames < frames) {
+		kvfree(plugin->buf);
+		plugin->buf = kvzalloc(size, GFP_KERNEL);
+		plugin->buf_frames = frames;
+	}
+	if (!plugin->buf) {
+		plugin->buf_frames = 0;
+		return -ENOMEM;
+	}
+	c = plugin->buf_channels;
+	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
+		for (channel = 0; channel < format->channels; channel++, c++) {
+			c->frames = frames;
+			c->enabled = 1;
+			c->wanted = 0;
+			c->area.addr = plugin->buf;
+			c->area.first = channel * width;
+			c->area.step = format->channels * width;
+		}
+	} else if (plugin->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
+		if (snd_BUG_ON(size % format->channels))
+			return -EINVAL;
+		size /= format->channels;
+		for (channel = 0; channel < format->channels; channel++, c++) {
+			c->frames = frames;
+			c->enabled = 1;
+			c->wanted = 0;
+			c->area.addr = plugin->buf + (channel * size);
+			c->area.first = 0;
+			c->area.step = width;
+		}
+	} else
+		return -EINVAL;
+	return 0;
+}
+
+int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
+{
+	int err;
+	if (snd_BUG_ON(!snd_pcm_plug_first(plug)))
+		return -ENXIO;
+	if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
+		struct snd_pcm_plugin *plugin = snd_pcm_plug_first(plug);
+		while (plugin->next) {
+			if (plugin->dst_frames)
+				frames = plugin->dst_frames(plugin, frames);
+			if ((snd_pcm_sframes_t)frames <= 0)
+				return -ENXIO;
+			plugin = plugin->next;
+			err = snd_pcm_plugin_alloc(plugin, frames);
+			if (err < 0)
+				return err;
+		}
+	} else {
+		struct snd_pcm_plugin *plugin = snd_pcm_plug_last(plug);
+		while (plugin->prev) {
+			if (plugin->src_frames)
+				frames = plugin->src_frames(plugin, frames);
+			if ((snd_pcm_sframes_t)frames <= 0)
+				return -ENXIO;
+			plugin = plugin->prev;
+			err = snd_pcm_plugin_alloc(plugin, frames);
+			if (err < 0)
+				return err;
+		}
+	}
+	return 0;
+}
+
+
+snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
+				       snd_pcm_uframes_t frames,
+				       struct snd_pcm_plugin_channel **channels)
+{
+	*channels = plugin->buf_channels;
+	return frames;
+}
+
+int snd_pcm_plugin_build(struct snd_pcm_substream *plug,
+			 const char *name,
+			 struct snd_pcm_plugin_format *src_format,
+			 struct snd_pcm_plugin_format *dst_format,
+			 size_t extra,
+			 struct snd_pcm_plugin **ret)
+{
+	struct snd_pcm_plugin *plugin;
+	unsigned int channels;
+	
+	if (snd_BUG_ON(!plug))
+		return -ENXIO;
+	if (snd_BUG_ON(!src_format || !dst_format))
+		return -ENXIO;
+	plugin = kzalloc(sizeof(*plugin) + extra, GFP_KERNEL);
+	if (plugin == NULL)
+		return -ENOMEM;
+	plugin->name = name;
+	plugin->plug = plug;
+	plugin->stream = snd_pcm_plug_stream(plug);
+	plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
+	plugin->src_format = *src_format;
+	plugin->src_width = snd_pcm_format_physical_width(src_format->format);
+	snd_BUG_ON(plugin->src_width <= 0);
+	plugin->dst_format = *dst_format;
+	plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
+	snd_BUG_ON(plugin->dst_width <= 0);
+	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		channels = src_format->channels;
+	else
+		channels = dst_format->channels;
+	plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
+	if (plugin->buf_channels == NULL) {
+		snd_pcm_plugin_free(plugin);
+		return -ENOMEM;
+	}
+	plugin->client_channels = snd_pcm_plugin_client_channels;
+	*ret = plugin;
+	return 0;
+}
+
+int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
+{
+	if (! plugin)
+		return 0;
+	if (plugin->private_free)
+		plugin->private_free(plugin);
+	kfree(plugin->buf_channels);
+	kvfree(plugin->buf);
+	kfree(plugin);
+	return 0;
+}
+
+static snd_pcm_sframes_t calc_dst_frames(struct snd_pcm_substream *plug,
+					 snd_pcm_sframes_t frames,
+					 bool check_size)
+{
+	struct snd_pcm_plugin *plugin, *plugin_next;
+
+	plugin = snd_pcm_plug_first(plug);
+	while (plugin && frames > 0) {
+		plugin_next = plugin->next;
+		if (check_size && plugin->buf_frames &&
+		    frames > plugin->buf_frames)
+			frames = plugin->buf_frames;
+		if (plugin->dst_frames) {
+			frames = plugin->dst_frames(plugin, frames);
+			if (frames < 0)
+				return frames;
+		}
+		plugin = plugin_next;
+	}
+	return frames;
+}
+
+static snd_pcm_sframes_t calc_src_frames(struct snd_pcm_substream *plug,
+					 snd_pcm_sframes_t frames,
+					 bool check_size)
+{
+	struct snd_pcm_plugin *plugin, *plugin_prev;
+
+	plugin = snd_pcm_plug_last(plug);
+	while (plugin && frames > 0) {
+		plugin_prev = plugin->prev;
+		if (plugin->src_frames) {
+			frames = plugin->src_frames(plugin, frames);
+			if (frames < 0)
+				return frames;
+		}
+		if (check_size && plugin->buf_frames &&
+		    frames > plugin->buf_frames)
+			frames = plugin->buf_frames;
+		plugin = plugin_prev;
+	}
+	return frames;
+}
+
+snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
+{
+	if (snd_BUG_ON(!plug))
+		return -ENXIO;
+	switch (snd_pcm_plug_stream(plug)) {
+	case SNDRV_PCM_STREAM_PLAYBACK:
+		return calc_src_frames(plug, drv_frames, false);
+	case SNDRV_PCM_STREAM_CAPTURE:
+		return calc_dst_frames(plug, drv_frames, false);
+	default:
+		snd_BUG();
+		return -EINVAL;
+	}
+}
+
+snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
+{
+	if (snd_BUG_ON(!plug))
+		return -ENXIO;
+	switch (snd_pcm_plug_stream(plug)) {
+	case SNDRV_PCM_STREAM_PLAYBACK:
+		return calc_dst_frames(plug, clt_frames, false);
+	case SNDRV_PCM_STREAM_CAPTURE:
+		return calc_src_frames(plug, clt_frames, false);
+	default:
+		snd_BUG();
+		return -EINVAL;
+	}
+}
+
+static int snd_pcm_plug_formats(const struct snd_mask *mask,
+				snd_pcm_format_t format)
+{
+	struct snd_mask formats = *mask;
+	u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
+		       SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
+		       SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
+		       SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
+		       SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
+		       SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
+		       SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
+		       SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
+		       SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
+	snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
+	
+	if (formats.bits[0] & lower_32_bits(linfmts))
+		formats.bits[0] |= lower_32_bits(linfmts);
+	if (formats.bits[1] & upper_32_bits(linfmts))
+		formats.bits[1] |= upper_32_bits(linfmts);
+	return snd_mask_test(&formats, (__force int)format);
+}
+
+static const snd_pcm_format_t preferred_formats[] = {
+	SNDRV_PCM_FORMAT_S16_LE,
+	SNDRV_PCM_FORMAT_S16_BE,
+	SNDRV_PCM_FORMAT_U16_LE,
+	SNDRV_PCM_FORMAT_U16_BE,
+	SNDRV_PCM_FORMAT_S24_3LE,
+	SNDRV_PCM_FORMAT_S24_3BE,
+	SNDRV_PCM_FORMAT_U24_3LE,
+	SNDRV_PCM_FORMAT_U24_3BE,
+	SNDRV_PCM_FORMAT_S24_LE,
+	SNDRV_PCM_FORMAT_S24_BE,
+	SNDRV_PCM_FORMAT_U24_LE,
+	SNDRV_PCM_FORMAT_U24_BE,
+	SNDRV_PCM_FORMAT_S32_LE,
+	SNDRV_PCM_FORMAT_S32_BE,
+	SNDRV_PCM_FORMAT_U32_LE,
+	SNDRV_PCM_FORMAT_U32_BE,
+	SNDRV_PCM_FORMAT_S8,
+	SNDRV_PCM_FORMAT_U8
+};
+
+snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
+					   const struct snd_mask *format_mask)
+{
+	int i;
+
+	if (snd_mask_test(format_mask, (__force int)format))
+		return format;
+	if (!snd_pcm_plug_formats(format_mask, format))
+		return (__force snd_pcm_format_t)-EINVAL;
+	if (snd_pcm_format_linear(format)) {
+		unsigned int width = snd_pcm_format_width(format);
+		int unsignd = snd_pcm_format_unsigned(format) > 0;
+		int big = snd_pcm_format_big_endian(format) > 0;
+		unsigned int badness, best = -1;
+		snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
+		for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
+			snd_pcm_format_t f = preferred_formats[i];
+			unsigned int w;
+			if (!snd_mask_test(format_mask, (__force int)f))
+				continue;
+			w = snd_pcm_format_width(f);
+			if (w >= width)
+				badness = w - width;
+			else
+				badness = width - w + 32;
+			badness += snd_pcm_format_unsigned(f) != unsignd;
+			badness += snd_pcm_format_big_endian(f) != big;
+			if (badness < best) {
+				best_format = f;
+				best = badness;
+			}
+		}
+		if ((__force int)best_format >= 0)
+			return best_format;
+		else
+			return (__force snd_pcm_format_t)-EINVAL;
+	} else {
+		switch (format) {
+		case SNDRV_PCM_FORMAT_MU_LAW:
+			for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
+				snd_pcm_format_t format1 = preferred_formats[i];
+				if (snd_mask_test(format_mask, (__force int)format1))
+					return format1;
+			}
+			fallthrough;
+		default:
+			return (__force snd_pcm_format_t)-EINVAL;
+		}
+	}
+}
+
+int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
+				struct snd_pcm_hw_params *params,
+				struct snd_pcm_hw_params *slave_params)
+{
+	struct snd_pcm_plugin_format tmpformat;
+	struct snd_pcm_plugin_format dstformat;
+	struct snd_pcm_plugin_format srcformat;
+	snd_pcm_access_t src_access, dst_access;
+	struct snd_pcm_plugin *plugin = NULL;
+	int err;
+	int stream = snd_pcm_plug_stream(plug);
+	int slave_interleaved = (params_channels(slave_params) == 1 ||
+				 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
+
+	switch (stream) {
+	case SNDRV_PCM_STREAM_PLAYBACK:
+		dstformat.format = params_format(slave_params);
+		dstformat.rate = params_rate(slave_params);
+		dstformat.channels = params_channels(slave_params);
+		srcformat.format = params_format(params);
+		srcformat.rate = params_rate(params);
+		srcformat.channels = params_channels(params);
+		src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
+		dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
+						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
+		break;
+	case SNDRV_PCM_STREAM_CAPTURE:
+		dstformat.format = params_format(params);
+		dstformat.rate = params_rate(params);
+		dstformat.channels = params_channels(params);
+		srcformat.format = params_format(slave_params);
+		srcformat.rate = params_rate(slave_params);
+		srcformat.channels = params_channels(slave_params);
+		src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
+						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
+		dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
+		break;
+	default:
+		snd_BUG();
+		return -EINVAL;
+	}
+	tmpformat = srcformat;
+		
+	pdprintf("srcformat: format=%i, rate=%i, channels=%i\n", 
+		 srcformat.format,
+		 srcformat.rate,
+		 srcformat.channels);
+	pdprintf("dstformat: format=%i, rate=%i, channels=%i\n", 
+		 dstformat.format,
+		 dstformat.rate,
+		 dstformat.channels);
+
+	/* Format change (linearization) */
+	if (! rate_match(srcformat.rate, dstformat.rate) &&
+	    ! snd_pcm_format_linear(srcformat.format)) {
+		if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
+			return -EINVAL;
+		tmpformat.format = SNDRV_PCM_FORMAT_S16;
+		err = snd_pcm_plugin_build_mulaw(plug,
+						 &srcformat, &tmpformat,
+						 &plugin);
+		if (err < 0)
+			return err;
+		err = snd_pcm_plugin_append(plugin);
+		if (err < 0) {
+			snd_pcm_plugin_free(plugin);
+			return err;
+		}
+		srcformat = tmpformat;
+		src_access = dst_access;
+	}
+
+	/* channels reduction */
+	if (srcformat.channels > dstformat.channels) {
+		tmpformat.channels = dstformat.channels;
+		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
+		pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
+		if (err < 0)
+			return err;
+		err = snd_pcm_plugin_append(plugin);
+		if (err < 0) {
+			snd_pcm_plugin_free(plugin);
+			return err;
+		}
+		srcformat = tmpformat;
+		src_access = dst_access;
+	}
+
+	/* rate resampling */
+	if (!rate_match(srcformat.rate, dstformat.rate)) {
+		if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
+			/* convert to S16 for resampling */
+			tmpformat.format = SNDRV_PCM_FORMAT_S16;
+			err = snd_pcm_plugin_build_linear(plug,
+							  &srcformat, &tmpformat,
+							  &plugin);
+			if (err < 0)
+				return err;
+			err = snd_pcm_plugin_append(plugin);
+			if (err < 0) {
+				snd_pcm_plugin_free(plugin);
+				return err;
+			}
+			srcformat = tmpformat;
+			src_access = dst_access;
+		}
+		tmpformat.rate = dstformat.rate;
+        	err = snd_pcm_plugin_build_rate(plug,
+        					&srcformat, &tmpformat,
+						&plugin);
+		pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
+		if (err < 0)
+			return err;
+		err = snd_pcm_plugin_append(plugin);
+		if (err < 0) {
+			snd_pcm_plugin_free(plugin);
+			return err;
+		}
+		srcformat = tmpformat;
+		src_access = dst_access;
+        }
+
+	/* format change */
+	if (srcformat.format != dstformat.format) {
+		tmpformat.format = dstformat.format;
+		if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
+		    tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
+			err = snd_pcm_plugin_build_mulaw(plug,
+							 &srcformat, &tmpformat,
+							 &plugin);
+		}
+		else if (snd_pcm_format_linear(srcformat.format) &&
+			 snd_pcm_format_linear(tmpformat.format)) {
+			err = snd_pcm_plugin_build_linear(plug,
+							  &srcformat, &tmpformat,
+							  &plugin);
+		}
+		else
+			return -EINVAL;
+		pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
+		if (err < 0)
+			return err;
+		err = snd_pcm_plugin_append(plugin);
+		if (err < 0) {
+			snd_pcm_plugin_free(plugin);
+			return err;
+		}
+		srcformat = tmpformat;
+		src_access = dst_access;
+	}
+
+	/* channels extension */
+	if (srcformat.channels < dstformat.channels) {
+		tmpformat.channels = dstformat.channels;
+		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
+		pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
+		if (err < 0)
+			return err;
+		err = snd_pcm_plugin_append(plugin);
+		if (err < 0) {
+			snd_pcm_plugin_free(plugin);
+			return err;
+		}
+		srcformat = tmpformat;
+		src_access = dst_access;
+	}
+
+	/* de-interleave */
+	if (src_access != dst_access) {
+		err = snd_pcm_plugin_build_copy(plug,
+						&srcformat,
+						&tmpformat,
+						&plugin);
+		pdprintf("interleave change (copy: returns %i)\n", err);
+		if (err < 0)
+			return err;
+		err = snd_pcm_plugin_append(plugin);
+		if (err < 0) {
+			snd_pcm_plugin_free(plugin);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
+					 char *buf,
+					 snd_pcm_uframes_t count,
+					 struct snd_pcm_plugin_channel **channels)
+{
+	struct snd_pcm_plugin *plugin;
+	struct snd_pcm_plugin_channel *v;
+	struct snd_pcm_plugin_format *format;
+	int width, nchannels, channel;
+	int stream = snd_pcm_plug_stream(plug);
+
+	if (snd_BUG_ON(!buf))
+		return -ENXIO;
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		plugin = snd_pcm_plug_first(plug);
+		format = &plugin->src_format;
+	} else {
+		plugin = snd_pcm_plug_last(plug);
+		format = &plugin->dst_format;
+	}
+	v = plugin->buf_channels;
+	*channels = v;
+	width = snd_pcm_format_physical_width(format->format);
+	if (width < 0)
+		return width;
+	nchannels = format->channels;
+	if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
+		       format->channels > 1))
+		return -ENXIO;
+	for (channel = 0; channel < nchannels; channel++, v++) {
+		v->frames = count;
+		v->enabled = 1;
+		v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
+		v->area.addr = buf;
+		v->area.first = channel * width;
+		v->area.step = nchannels * width;
+	}
+	return count;
+}
+
+snd_pcm_sframes_t snd_pcm_plug_write_transfer(struct snd_pcm_substream *plug, struct snd_pcm_plugin_channel *src_channels, snd_pcm_uframes_t size)
+{
+	struct snd_pcm_plugin *plugin, *next;
+	struct snd_pcm_plugin_channel *dst_channels;
+	int err;
+	snd_pcm_sframes_t frames = size;
+
+	plugin = snd_pcm_plug_first(plug);
+	while (plugin) {
+		if (frames <= 0)
+			return frames;
+		next = plugin->next;
+		if (next) {
+			snd_pcm_sframes_t frames1 = frames;
+			if (plugin->dst_frames) {
+				frames1 = plugin->dst_frames(plugin, frames);
+				if (frames1 <= 0)
+					return frames1;
+			}
+			err = next->client_channels(next, frames1, &dst_channels);
+			if (err < 0)
+				return err;
+			if (err != frames1) {
+				frames = err;
+				if (plugin->src_frames) {
+					frames = plugin->src_frames(plugin, frames1);
+					if (frames <= 0)
+						return frames;
+				}
+			}
+		} else
+			dst_channels = NULL;
+		pdprintf("write plugin: %s, %li\n", plugin->name, frames);
+		frames = plugin->transfer(plugin, src_channels, dst_channels, frames);
+		if (frames < 0)
+			return frames;
+		src_channels = dst_channels;
+		plugin = next;
+	}
+	return calc_src_frames(plug, frames, true);
+}
+
+snd_pcm_sframes_t snd_pcm_plug_read_transfer(struct snd_pcm_substream *plug, struct snd_pcm_plugin_channel *dst_channels_final, snd_pcm_uframes_t size)
+{
+	struct snd_pcm_plugin *plugin, *next;
+	struct snd_pcm_plugin_channel *src_channels, *dst_channels;
+	snd_pcm_sframes_t frames = size;
+	int err;
+
+	frames = calc_src_frames(plug, frames, true);
+	if (frames < 0)
+		return frames;
+
+	src_channels = NULL;
+	plugin = snd_pcm_plug_first(plug);
+	while (plugin && frames > 0) {
+		next = plugin->next;
+		if (next) {
+			err = plugin->client_channels(plugin, frames, &dst_channels);
+			if (err < 0)
+				return err;
+			frames = err;
+		} else {
+			dst_channels = dst_channels_final;
+		}
+		pdprintf("read plugin: %s, %li\n", plugin->name, frames);
+		frames = plugin->transfer(plugin, src_channels, dst_channels, frames);
+		if (frames < 0)
+			return frames;
+		plugin = next;
+		src_channels = dst_channels;
+	}
+	return frames;
+}
+
+int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
+			 size_t samples, snd_pcm_format_t format)
+{
+	/* FIXME: sub byte resolution and odd dst_offset */
+	unsigned char *dst;
+	unsigned int dst_step;
+	int width;
+	const unsigned char *silence;
+	if (!dst_area->addr)
+		return 0;
+	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
+	width = snd_pcm_format_physical_width(format);
+	if (width <= 0)
+		return -EINVAL;
+	if (dst_area->step == (unsigned int) width && width >= 8)
+		return snd_pcm_format_set_silence(format, dst, samples);
+	silence = snd_pcm_format_silence_64(format);
+	if (! silence)
+		return -EINVAL;
+	dst_step = dst_area->step / 8;
+	if (width == 4) {
+		/* Ima ADPCM */
+		int dstbit = dst_area->first % 8;
+		int dstbit_step = dst_area->step % 8;
+		while (samples-- > 0) {
+			if (dstbit)
+				*dst &= 0xf0;
+			else
+				*dst &= 0x0f;
+			dst += dst_step;
+			dstbit += dstbit_step;
+			if (dstbit == 8) {
+				dst++;
+				dstbit = 0;
+			}
+		}
+	} else {
+		width /= 8;
+		while (samples-- > 0) {
+			memcpy(dst, silence, width);
+			dst += dst_step;
+		}
+	}
+	return 0;
+}
+
+int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
+		      const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
+		      size_t samples, snd_pcm_format_t format)
+{
+	/* FIXME: sub byte resolution and odd dst_offset */
+	char *src, *dst;
+	int width;
+	int src_step, dst_step;
+	src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
+	if (!src_area->addr)
+		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
+	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
+	if (!dst_area->addr)
+		return 0;
+	width = snd_pcm_format_physical_width(format);
+	if (width <= 0)
+		return -EINVAL;
+	if (src_area->step == (unsigned int) width &&
+	    dst_area->step == (unsigned int) width && width >= 8) {
+		size_t bytes = samples * width / 8;
+		memcpy(dst, src, bytes);
+		return 0;
+	}
+	src_step = src_area->step / 8;
+	dst_step = dst_area->step / 8;
+	if (width == 4) {
+		/* Ima ADPCM */
+		int srcbit = src_area->first % 8;
+		int srcbit_step = src_area->step % 8;
+		int dstbit = dst_area->first % 8;
+		int dstbit_step = dst_area->step % 8;
+		while (samples-- > 0) {
+			unsigned char srcval;
+			if (srcbit)
+				srcval = *src & 0x0f;
+			else
+				srcval = (*src & 0xf0) >> 4;
+			if (dstbit)
+				*dst = (*dst & 0xf0) | srcval;
+			else
+				*dst = (*dst & 0x0f) | (srcval << 4);
+			src += src_step;
+			srcbit += srcbit_step;
+			if (srcbit == 8) {
+				src++;
+				srcbit = 0;
+			}
+			dst += dst_step;
+			dstbit += dstbit_step;
+			if (dstbit == 8) {
+				dst++;
+				dstbit = 0;
+			}
+		}
+	} else {
+		width /= 8;
+		while (samples-- > 0) {
+			memcpy(dst, src, width);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+	return 0;
+}
diff --git a/sound/core/oss/pcm_plugin.h b/sound/core/oss/pcm_plugin.h
new file mode 100644
index 0000000000..50a6b50f5d
--- /dev/null
+++ b/sound/core/oss/pcm_plugin.h
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __PCM_PLUGIN_H
+#define __PCM_PLUGIN_H
+
+/*
+ *  Digital Audio (Plugin interface) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#ifdef CONFIG_SND_PCM_OSS_PLUGINS
+
+#define snd_pcm_plug_stream(plug) ((plug)->stream)
+
+enum snd_pcm_plugin_action {
+	INIT = 0,
+	PREPARE = 1,
+};
+
+struct snd_pcm_channel_area {
+	void *addr;			/* base address of channel samples */
+	unsigned int first;		/* offset to first sample in bits */
+	unsigned int step;		/* samples distance in bits */
+};
+
+struct snd_pcm_plugin_channel {
+	void *aptr;			/* pointer to the allocated area */
+	struct snd_pcm_channel_area area;
+	snd_pcm_uframes_t frames;	/* allocated frames */
+	unsigned int enabled:1;		/* channel need to be processed */
+	unsigned int wanted:1;		/* channel is wanted */
+};
+
+struct snd_pcm_plugin_format {
+	snd_pcm_format_t format;
+	unsigned int rate;
+	unsigned int channels;
+};
+
+struct snd_pcm_plugin {
+	const char *name;		/* plug-in name */
+	int stream;
+	struct snd_pcm_plugin_format src_format;	/* source format */
+	struct snd_pcm_plugin_format dst_format;	/* destination format */
+	int src_width;			/* sample width in bits */
+	int dst_width;			/* sample width in bits */
+	snd_pcm_access_t access;
+	snd_pcm_sframes_t (*src_frames)(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t dst_frames);
+	snd_pcm_sframes_t (*dst_frames)(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t src_frames);
+	snd_pcm_sframes_t (*client_channels)(struct snd_pcm_plugin *plugin,
+					     snd_pcm_uframes_t frames,
+					     struct snd_pcm_plugin_channel **channels);
+	snd_pcm_sframes_t (*transfer)(struct snd_pcm_plugin *plugin,
+				      const struct snd_pcm_plugin_channel *src_channels,
+				      struct snd_pcm_plugin_channel *dst_channels,
+				      snd_pcm_uframes_t frames);
+	int (*action)(struct snd_pcm_plugin *plugin,
+		      enum snd_pcm_plugin_action action,
+		      unsigned long data);
+	struct snd_pcm_plugin *prev;
+	struct snd_pcm_plugin *next;
+	struct snd_pcm_substream *plug;
+	void *private_data;
+	void (*private_free)(struct snd_pcm_plugin *plugin);
+	char *buf;
+	snd_pcm_uframes_t buf_frames;
+	struct snd_pcm_plugin_channel *buf_channels;
+	char extra_data[];
+};
+
+int snd_pcm_plugin_build(struct snd_pcm_substream *handle,
+                         const char *name,
+                         struct snd_pcm_plugin_format *src_format,
+                         struct snd_pcm_plugin_format *dst_format,
+                         size_t extra,
+                         struct snd_pcm_plugin **ret);
+int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin);
+int snd_pcm_plugin_clear(struct snd_pcm_plugin **first);
+int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames);
+snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *handle, snd_pcm_uframes_t drv_size);
+snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *handle, snd_pcm_uframes_t clt_size);
+
+#define FULL ROUTE_PLUGIN_RESOLUTION
+#define HALF ROUTE_PLUGIN_RESOLUTION / 2
+
+int snd_pcm_plugin_build_io(struct snd_pcm_substream *handle,
+			    struct snd_pcm_hw_params *params,
+			    struct snd_pcm_plugin **r_plugin);
+int snd_pcm_plugin_build_linear(struct snd_pcm_substream *handle,
+				struct snd_pcm_plugin_format *src_format,
+				struct snd_pcm_plugin_format *dst_format,
+				struct snd_pcm_plugin **r_plugin);
+int snd_pcm_plugin_build_mulaw(struct snd_pcm_substream *handle,
+			       struct snd_pcm_plugin_format *src_format,
+			       struct snd_pcm_plugin_format *dst_format,
+			       struct snd_pcm_plugin **r_plugin);
+int snd_pcm_plugin_build_rate(struct snd_pcm_substream *handle,
+			      struct snd_pcm_plugin_format *src_format,
+			      struct snd_pcm_plugin_format *dst_format,
+			      struct snd_pcm_plugin **r_plugin);
+int snd_pcm_plugin_build_route(struct snd_pcm_substream *handle,
+			       struct snd_pcm_plugin_format *src_format,
+			       struct snd_pcm_plugin_format *dst_format,
+		               struct snd_pcm_plugin **r_plugin);
+int snd_pcm_plugin_build_copy(struct snd_pcm_substream *handle,
+			      struct snd_pcm_plugin_format *src_format,
+			      struct snd_pcm_plugin_format *dst_format,
+			      struct snd_pcm_plugin **r_plugin);
+
+int snd_pcm_plug_format_plugins(struct snd_pcm_substream *substream,
+				struct snd_pcm_hw_params *params,
+				struct snd_pcm_hw_params *slave_params);
+
+snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
+					   const struct snd_mask *format_mask);
+
+int snd_pcm_plugin_append(struct snd_pcm_plugin *plugin);
+
+snd_pcm_sframes_t snd_pcm_plug_write_transfer(struct snd_pcm_substream *handle,
+					      struct snd_pcm_plugin_channel *src_channels,
+					      snd_pcm_uframes_t size);
+snd_pcm_sframes_t snd_pcm_plug_read_transfer(struct snd_pcm_substream *handle,
+					     struct snd_pcm_plugin_channel *dst_channels_final,
+					     snd_pcm_uframes_t size);
+
+snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *handle,
+						   char *buf, snd_pcm_uframes_t count,
+						   struct snd_pcm_plugin_channel **channels);
+
+snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
+						 snd_pcm_uframes_t frames,
+						 struct snd_pcm_plugin_channel **channels);
+
+int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_channel,
+			 size_t dst_offset,
+			 size_t samples, snd_pcm_format_t format);
+int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_channel,
+		      size_t src_offset,
+		      const struct snd_pcm_channel_area *dst_channel,
+		      size_t dst_offset,
+		      size_t samples, snd_pcm_format_t format);
+
+void *snd_pcm_plug_buf_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t size);
+void snd_pcm_plug_buf_unlock(struct snd_pcm_substream *plug, void *ptr);
+#else
+
+static inline snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *handle, snd_pcm_uframes_t drv_size) { return drv_size; }
+static inline snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *handle, snd_pcm_uframes_t clt_size) { return clt_size; }
+static inline int snd_pcm_plug_slave_format(int format, const struct snd_mask *format_mask) { return format; }
+
+#endif
+
+snd_pcm_sframes_t snd_pcm_oss_write3(struct snd_pcm_substream *substream,
+				     const char *ptr, snd_pcm_uframes_t size,
+				     int in_kernel);
+snd_pcm_sframes_t snd_pcm_oss_read3(struct snd_pcm_substream *substream,
+				    char *ptr, snd_pcm_uframes_t size, int in_kernel);
+snd_pcm_sframes_t snd_pcm_oss_writev3(struct snd_pcm_substream *substream,
+				      void **bufs, snd_pcm_uframes_t frames);
+snd_pcm_sframes_t snd_pcm_oss_readv3(struct snd_pcm_substream *substream,
+				     void **bufs, snd_pcm_uframes_t frames);
+
+#ifdef PLUGIN_DEBUG
+#define pdprintf(fmt, args...) printk(KERN_DEBUG "plugin: " fmt, ##args)
+#else
+#define pdprintf(fmt, args...)
+#endif
+
+#endif				/* __PCM_PLUGIN_H */
diff --git a/sound/core/oss/rate.c b/sound/core/oss/rate.c
new file mode 100644
index 0000000000..9826911934
--- /dev/null
+++ b/sound/core/oss/rate.c
@@ -0,0 +1,348 @@
+/*
+ *  Rate conversion Plug-In
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+  
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+#define SHIFT	11
+#define BITS	(1<<SHIFT)
+#define R_MASK	(BITS-1)
+
+/*
+ *  Basic rate conversion plugin
+ */
+
+struct rate_channel {
+	signed short last_S1;
+	signed short last_S2;
+};
+ 
+typedef void (*rate_f)(struct snd_pcm_plugin *plugin,
+		       const struct snd_pcm_plugin_channel *src_channels,
+		       struct snd_pcm_plugin_channel *dst_channels,
+		       int src_frames, int dst_frames);
+
+struct rate_priv {
+	unsigned int pitch;
+	unsigned int pos;
+	rate_f func;
+	snd_pcm_sframes_t old_src_frames, old_dst_frames;
+	struct rate_channel channels[];
+};
+
+static void rate_init(struct snd_pcm_plugin *plugin)
+{
+	unsigned int channel;
+	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
+	data->pos = 0;
+	for (channel = 0; channel < plugin->src_format.channels; channel++) {
+		data->channels[channel].last_S1 = 0;
+		data->channels[channel].last_S2 = 0;
+	}
+}
+
+static void resample_expand(struct snd_pcm_plugin *plugin,
+			    const struct snd_pcm_plugin_channel *src_channels,
+			    struct snd_pcm_plugin_channel *dst_channels,
+			    int src_frames, int dst_frames)
+{
+	unsigned int pos = 0;
+	signed int val;
+	signed short S1, S2;
+	signed short *src, *dst;
+	unsigned int channel;
+	int src_step, dst_step;
+	int src_frames1, dst_frames1;
+	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
+	struct rate_channel *rchannels = data->channels;
+	
+	for (channel = 0; channel < plugin->src_format.channels; channel++) {
+		pos = data->pos;
+		S1 = rchannels->last_S1;
+		S2 = rchannels->last_S2;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = (signed short *)src_channels[channel].area.addr +
+			src_channels[channel].area.first / 8 / 2;
+		dst = (signed short *)dst_channels[channel].area.addr +
+			dst_channels[channel].area.first / 8 / 2;
+		src_step = src_channels[channel].area.step / 8 / 2;
+		dst_step = dst_channels[channel].area.step / 8 / 2;
+		src_frames1 = src_frames;
+		dst_frames1 = dst_frames;
+		while (dst_frames1-- > 0) {
+			if (pos & ~R_MASK) {
+				pos &= R_MASK;
+				S1 = S2;
+				if (src_frames1-- > 0) {
+					S2 = *src;
+					src += src_step;
+				}
+			}
+			val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
+			if (val < -32768)
+				val = -32768;
+			else if (val > 32767)
+				val = 32767;
+			*dst = val;
+			dst += dst_step;
+			pos += data->pitch;
+		}
+		rchannels->last_S1 = S1;
+		rchannels->last_S2 = S2;
+		rchannels++;
+	}
+	data->pos = pos;
+}
+
+static void resample_shrink(struct snd_pcm_plugin *plugin,
+			    const struct snd_pcm_plugin_channel *src_channels,
+			    struct snd_pcm_plugin_channel *dst_channels,
+			    int src_frames, int dst_frames)
+{
+	unsigned int pos = 0;
+	signed int val;
+	signed short S1, S2;
+	signed short *src, *dst;
+	unsigned int channel;
+	int src_step, dst_step;
+	int src_frames1, dst_frames1;
+	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
+	struct rate_channel *rchannels = data->channels;
+
+	for (channel = 0; channel < plugin->src_format.channels; ++channel) {
+		pos = data->pos;
+		S1 = rchannels->last_S1;
+		S2 = rchannels->last_S2;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = (signed short *)src_channels[channel].area.addr +
+			src_channels[channel].area.first / 8 / 2;
+		dst = (signed short *)dst_channels[channel].area.addr +
+			dst_channels[channel].area.first / 8 / 2;
+		src_step = src_channels[channel].area.step / 8 / 2;
+		dst_step = dst_channels[channel].area.step / 8 / 2;
+		src_frames1 = src_frames;
+		dst_frames1 = dst_frames;
+		while (dst_frames1 > 0) {
+			S1 = S2;
+			if (src_frames1-- > 0) {
+				S2 = *src;
+				src += src_step;
+			}
+			if (pos & ~R_MASK) {
+				pos &= R_MASK;
+				val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
+				if (val < -32768)
+					val = -32768;
+				else if (val > 32767)
+					val = 32767;
+				*dst = val;
+				dst += dst_step;
+				dst_frames1--;
+			}
+			pos += data->pitch;
+		}
+		rchannels->last_S1 = S1;
+		rchannels->last_S2 = S2;
+		rchannels++;
+	}
+	data->pos = pos;
+}
+
+static snd_pcm_sframes_t rate_src_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
+{
+	struct rate_priv *data;
+	snd_pcm_sframes_t res;
+
+	if (snd_BUG_ON(!plugin))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+	data = (struct rate_priv *)plugin->extra_data;
+	if (plugin->src_format.rate < plugin->dst_format.rate) {
+		res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
+	} else {
+		res = DIV_ROUND_CLOSEST(frames << SHIFT, data->pitch);
+	}
+	if (data->old_src_frames > 0) {
+		snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames;
+		while (data->old_src_frames < frames1) {
+			frames1 >>= 1;
+			res1 <<= 1;
+		}
+		while (data->old_src_frames > frames1) {
+			frames1 <<= 1;
+			res1 >>= 1;
+		}
+		if (data->old_src_frames == frames1)
+			return res1;
+	}
+	data->old_src_frames = frames;
+	data->old_dst_frames = res;
+	return res;
+}
+
+static snd_pcm_sframes_t rate_dst_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
+{
+	struct rate_priv *data;
+	snd_pcm_sframes_t res;
+
+	if (snd_BUG_ON(!plugin))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+	data = (struct rate_priv *)plugin->extra_data;
+	if (plugin->src_format.rate < plugin->dst_format.rate) {
+		res = DIV_ROUND_CLOSEST(frames << SHIFT, data->pitch);
+	} else {
+		res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
+	}
+	if (data->old_dst_frames > 0) {
+		snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames;
+		while (data->old_dst_frames < frames1) {
+			frames1 >>= 1;
+			res1 <<= 1;
+		}
+		while (data->old_dst_frames > frames1) {
+			frames1 <<= 1;
+			res1 >>= 1;
+		}
+		if (data->old_dst_frames == frames1)
+			return res1;
+	}
+	data->old_dst_frames = frames;
+	data->old_src_frames = res;
+	return res;
+}
+
+static snd_pcm_sframes_t rate_transfer(struct snd_pcm_plugin *plugin,
+			     const struct snd_pcm_plugin_channel *src_channels,
+			     struct snd_pcm_plugin_channel *dst_channels,
+			     snd_pcm_uframes_t frames)
+{
+	snd_pcm_uframes_t dst_frames;
+	struct rate_priv *data;
+
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+#ifdef CONFIG_SND_DEBUG
+	{
+		unsigned int channel;
+		for (channel = 0; channel < plugin->src_format.channels; channel++) {
+			if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
+				       src_channels[channel].area.step % 8))
+				return -ENXIO;
+			if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
+				       dst_channels[channel].area.step % 8))
+				return -ENXIO;
+		}
+	}
+#endif
+
+	dst_frames = rate_dst_frames(plugin, frames);
+	if (dst_frames > dst_channels[0].frames)
+		dst_frames = dst_channels[0].frames;
+	data = (struct rate_priv *)plugin->extra_data;
+	data->func(plugin, src_channels, dst_channels, frames, dst_frames);
+	return dst_frames;
+}
+
+static int rate_action(struct snd_pcm_plugin *plugin,
+		       enum snd_pcm_plugin_action action,
+		       unsigned long udata)
+{
+	if (snd_BUG_ON(!plugin))
+		return -ENXIO;
+	switch (action) {
+	case INIT:
+	case PREPARE:
+		rate_init(plugin);
+		break;
+	default:
+		break;
+	}
+	return 0;	/* silenty ignore other actions */
+}
+
+int snd_pcm_plugin_build_rate(struct snd_pcm_substream *plug,
+			      struct snd_pcm_plugin_format *src_format,
+			      struct snd_pcm_plugin_format *dst_format,
+			      struct snd_pcm_plugin **r_plugin)
+{
+	int err;
+	struct rate_priv *data;
+	struct snd_pcm_plugin *plugin;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+
+	if (snd_BUG_ON(src_format->channels != dst_format->channels))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->channels <= 0))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->format != SNDRV_PCM_FORMAT_S16))
+		return -ENXIO;
+	if (snd_BUG_ON(dst_format->format != SNDRV_PCM_FORMAT_S16))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->rate == dst_format->rate))
+		return -ENXIO;
+
+	err = snd_pcm_plugin_build(plug, "rate conversion",
+				   src_format, dst_format,
+				   struct_size(data, channels,
+					       src_format->channels),
+				   &plugin);
+	if (err < 0)
+		return err;
+	data = (struct rate_priv *)plugin->extra_data;
+	if (src_format->rate < dst_format->rate) {
+		data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate;
+		data->func = resample_expand;
+	} else {
+		data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate;
+		data->func = resample_shrink;
+	}
+	data->pos = 0;
+	rate_init(plugin);
+	data->old_src_frames = data->old_dst_frames = 0;
+	plugin->transfer = rate_transfer;
+	plugin->src_frames = rate_src_frames;
+	plugin->dst_frames = rate_dst_frames;
+	plugin->action = rate_action;
+	*r_plugin = plugin;
+	return 0;
+}
diff --git a/sound/core/oss/route.c b/sound/core/oss/route.c
new file mode 100644
index 0000000000..72dea04197
--- /dev/null
+++ b/sound/core/oss/route.c
@@ -0,0 +1,111 @@
+/*
+ *  Route Plug-In
+ *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+static void zero_areas(struct snd_pcm_plugin_channel *dvp, int ndsts,
+		       snd_pcm_uframes_t frames, snd_pcm_format_t format)
+{
+	int dst = 0;
+	for (; dst < ndsts; ++dst) {
+		if (dvp->wanted)
+			snd_pcm_area_silence(&dvp->area, 0, frames, format);
+		dvp->enabled = 0;
+		dvp++;
+	}
+}
+
+static inline void copy_area(const struct snd_pcm_plugin_channel *src_channel,
+			     struct snd_pcm_plugin_channel *dst_channel,
+			     snd_pcm_uframes_t frames, snd_pcm_format_t format)
+{
+	dst_channel->enabled = 1;
+	snd_pcm_area_copy(&src_channel->area, 0, &dst_channel->area, 0, frames, format);
+}
+
+static snd_pcm_sframes_t route_transfer(struct snd_pcm_plugin *plugin,
+					const struct snd_pcm_plugin_channel *src_channels,
+					struct snd_pcm_plugin_channel *dst_channels,
+					snd_pcm_uframes_t frames)
+{
+	int nsrcs, ndsts, dst;
+	struct snd_pcm_plugin_channel *dvp;
+	snd_pcm_format_t format;
+
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+	if (frames > dst_channels[0].frames)
+		frames = dst_channels[0].frames;
+
+	nsrcs = plugin->src_format.channels;
+	ndsts = plugin->dst_format.channels;
+
+	format = plugin->dst_format.format;
+	dvp = dst_channels;
+	if (nsrcs <= 1) {
+		/* expand to all channels */
+		for (dst = 0; dst < ndsts; ++dst) {
+			copy_area(src_channels, dvp, frames, format);
+			dvp++;
+		}
+		return frames;
+	}
+
+	for (dst = 0; dst < ndsts && dst < nsrcs; ++dst) {
+		copy_area(src_channels, dvp, frames, format);
+		dvp++;
+		src_channels++;
+	}
+	if (dst < ndsts)
+		zero_areas(dvp, ndsts - dst, frames, format);
+	return frames;
+}
+
+int snd_pcm_plugin_build_route(struct snd_pcm_substream *plug,
+			       struct snd_pcm_plugin_format *src_format,
+			       struct snd_pcm_plugin_format *dst_format,
+			       struct snd_pcm_plugin **r_plugin)
+{
+	struct snd_pcm_plugin *plugin;
+	int err;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+	if (snd_BUG_ON(src_format->rate != dst_format->rate))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->format != dst_format->format))
+		return -ENXIO;
+
+	err = snd_pcm_plugin_build(plug, "route conversion",
+				   src_format, dst_format, 0, &plugin);
+	if (err < 0)
+		return err;
+
+	plugin->transfer = route_transfer;
+	*r_plugin = plugin;
+	return 0;
+}
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
new file mode 100644
index 0000000000..6d0c9c3779
--- /dev/null
+++ b/sound/core/pcm.c
@@ -0,0 +1,1249 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/nospec.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/pcm.h>
+#include <sound/timer.h>
+#include <sound/control.h>
+#include <sound/info.h>
+
+#include "pcm_local.h"
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
+MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
+MODULE_LICENSE("GPL");
+
+static LIST_HEAD(snd_pcm_devices);
+static DEFINE_MUTEX(register_mutex);
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+static LIST_HEAD(snd_pcm_notify_list);
+#endif
+
+static int snd_pcm_free(struct snd_pcm *pcm);
+static int snd_pcm_dev_free(struct snd_device *device);
+static int snd_pcm_dev_register(struct snd_device *device);
+static int snd_pcm_dev_disconnect(struct snd_device *device);
+
+static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
+{
+	struct snd_pcm *pcm;
+
+	list_for_each_entry(pcm, &snd_pcm_devices, list) {
+		if (pcm->card == card && pcm->device == device)
+			return pcm;
+	}
+	return NULL;
+}
+
+static int snd_pcm_next(struct snd_card *card, int device)
+{
+	struct snd_pcm *pcm;
+
+	list_for_each_entry(pcm, &snd_pcm_devices, list) {
+		if (pcm->card == card && pcm->device > device)
+			return pcm->device;
+		else if (pcm->card->number > card->number)
+			return -1;
+	}
+	return -1;
+}
+
+static int snd_pcm_add(struct snd_pcm *newpcm)
+{
+	struct snd_pcm *pcm;
+
+	if (newpcm->internal)
+		return 0;
+
+	list_for_each_entry(pcm, &snd_pcm_devices, list) {
+		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
+			return -EBUSY;
+		if (pcm->card->number > newpcm->card->number ||
+				(pcm->card == newpcm->card &&
+				pcm->device > newpcm->device)) {
+			list_add(&newpcm->list, pcm->list.prev);
+			return 0;
+		}
+	}
+	list_add_tail(&newpcm->list, &snd_pcm_devices);
+	return 0;
+}
+
+static int snd_pcm_control_ioctl(struct snd_card *card,
+				 struct snd_ctl_file *control,
+				 unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
+		{
+			int device;
+
+			if (get_user(device, (int __user *)arg))
+				return -EFAULT;
+			mutex_lock(&register_mutex);
+			device = snd_pcm_next(card, device);
+			mutex_unlock(&register_mutex);
+			if (put_user(device, (int __user *)arg))
+				return -EFAULT;
+			return 0;
+		}
+	case SNDRV_CTL_IOCTL_PCM_INFO:
+		{
+			struct snd_pcm_info __user *info;
+			unsigned int device, subdevice;
+			int stream;
+			struct snd_pcm *pcm;
+			struct snd_pcm_str *pstr;
+			struct snd_pcm_substream *substream;
+			int err;
+
+			info = (struct snd_pcm_info __user *)arg;
+			if (get_user(device, &info->device))
+				return -EFAULT;
+			if (get_user(stream, &info->stream))
+				return -EFAULT;
+			if (stream < 0 || stream > 1)
+				return -EINVAL;
+			stream = array_index_nospec(stream, 2);
+			if (get_user(subdevice, &info->subdevice))
+				return -EFAULT;
+			mutex_lock(&register_mutex);
+			pcm = snd_pcm_get(card, device);
+			if (pcm == NULL) {
+				err = -ENXIO;
+				goto _error;
+			}
+			pstr = &pcm->streams[stream];
+			if (pstr->substream_count == 0) {
+				err = -ENOENT;
+				goto _error;
+			}
+			if (subdevice >= pstr->substream_count) {
+				err = -ENXIO;
+				goto _error;
+			}
+			for (substream = pstr->substream; substream;
+			     substream = substream->next)
+				if (substream->number == (int)subdevice)
+					break;
+			if (substream == NULL) {
+				err = -ENXIO;
+				goto _error;
+			}
+			mutex_lock(&pcm->open_mutex);
+			err = snd_pcm_info_user(substream, info);
+			mutex_unlock(&pcm->open_mutex);
+		_error:
+			mutex_unlock(&register_mutex);
+			return err;
+		}
+	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
+		{
+			int val;
+			
+			if (get_user(val, (int __user *)arg))
+				return -EFAULT;
+			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
+			return 0;
+		}
+	}
+	return -ENOIOCTLCMD;
+}
+
+#define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
+
+static const char * const snd_pcm_format_names[] = {
+	FORMAT(S8),
+	FORMAT(U8),
+	FORMAT(S16_LE),
+	FORMAT(S16_BE),
+	FORMAT(U16_LE),
+	FORMAT(U16_BE),
+	FORMAT(S24_LE),
+	FORMAT(S24_BE),
+	FORMAT(U24_LE),
+	FORMAT(U24_BE),
+	FORMAT(S32_LE),
+	FORMAT(S32_BE),
+	FORMAT(U32_LE),
+	FORMAT(U32_BE),
+	FORMAT(FLOAT_LE),
+	FORMAT(FLOAT_BE),
+	FORMAT(FLOAT64_LE),
+	FORMAT(FLOAT64_BE),
+	FORMAT(IEC958_SUBFRAME_LE),
+	FORMAT(IEC958_SUBFRAME_BE),
+	FORMAT(MU_LAW),
+	FORMAT(A_LAW),
+	FORMAT(IMA_ADPCM),
+	FORMAT(MPEG),
+	FORMAT(GSM),
+	FORMAT(SPECIAL),
+	FORMAT(S24_3LE),
+	FORMAT(S24_3BE),
+	FORMAT(U24_3LE),
+	FORMAT(U24_3BE),
+	FORMAT(S20_3LE),
+	FORMAT(S20_3BE),
+	FORMAT(U20_3LE),
+	FORMAT(U20_3BE),
+	FORMAT(S18_3LE),
+	FORMAT(S18_3BE),
+	FORMAT(U18_3LE),
+	FORMAT(U18_3BE),
+	FORMAT(G723_24),
+	FORMAT(G723_24_1B),
+	FORMAT(G723_40),
+	FORMAT(G723_40_1B),
+	FORMAT(DSD_U8),
+	FORMAT(DSD_U16_LE),
+	FORMAT(DSD_U32_LE),
+	FORMAT(DSD_U16_BE),
+	FORMAT(DSD_U32_BE),
+};
+
+/**
+ * snd_pcm_format_name - Return a name string for the given PCM format
+ * @format: PCM format
+ *
+ * Return: the format name string
+ */
+const char *snd_pcm_format_name(snd_pcm_format_t format)
+{
+	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
+		return "Unknown";
+	return snd_pcm_format_names[(__force unsigned int)format];
+}
+EXPORT_SYMBOL_GPL(snd_pcm_format_name);
+
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+
+#define STATE(v) [SNDRV_PCM_STATE_##v] = #v
+#define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
+#define READY(v) [SNDRV_PCM_READY_##v] = #v
+#define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
+#define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
+#define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
+#define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
+#define START(v) [SNDRV_PCM_START_##v] = #v
+#define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v 
+
+static const char * const snd_pcm_stream_names[] = {
+	STREAM(PLAYBACK),
+	STREAM(CAPTURE),
+};
+
+static const char * const snd_pcm_state_names[] = {
+	STATE(OPEN),
+	STATE(SETUP),
+	STATE(PREPARED),
+	STATE(RUNNING),
+	STATE(XRUN),
+	STATE(DRAINING),
+	STATE(PAUSED),
+	STATE(SUSPENDED),
+	STATE(DISCONNECTED),
+};
+
+static const char * const snd_pcm_access_names[] = {
+	ACCESS(MMAP_INTERLEAVED), 
+	ACCESS(MMAP_NONINTERLEAVED),
+	ACCESS(MMAP_COMPLEX),
+	ACCESS(RW_INTERLEAVED),
+	ACCESS(RW_NONINTERLEAVED),
+};
+
+static const char * const snd_pcm_subformat_names[] = {
+	SUBFORMAT(STD), 
+};
+
+static const char * const snd_pcm_tstamp_mode_names[] = {
+	TSTAMP(NONE),
+	TSTAMP(ENABLE),
+};
+
+static const char *snd_pcm_stream_name(int stream)
+{
+	return snd_pcm_stream_names[stream];
+}
+
+static const char *snd_pcm_access_name(snd_pcm_access_t access)
+{
+	return snd_pcm_access_names[(__force int)access];
+}
+
+static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
+{
+	return snd_pcm_subformat_names[(__force int)subformat];
+}
+
+static const char *snd_pcm_tstamp_mode_name(int mode)
+{
+	return snd_pcm_tstamp_mode_names[mode];
+}
+
+static const char *snd_pcm_state_name(snd_pcm_state_t state)
+{
+	return snd_pcm_state_names[(__force int)state];
+}
+
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+#include <linux/soundcard.h>
+
+static const char *snd_pcm_oss_format_name(int format)
+{
+	switch (format) {
+	case AFMT_MU_LAW:
+		return "MU_LAW";
+	case AFMT_A_LAW:
+		return "A_LAW";
+	case AFMT_IMA_ADPCM:
+		return "IMA_ADPCM";
+	case AFMT_U8:
+		return "U8";
+	case AFMT_S16_LE:
+		return "S16_LE";
+	case AFMT_S16_BE:
+		return "S16_BE";
+	case AFMT_S8:
+		return "S8";
+	case AFMT_U16_LE:
+		return "U16_LE";
+	case AFMT_U16_BE:
+		return "U16_BE";
+	case AFMT_MPEG:
+		return "MPEG";
+	default:
+		return "unknown";
+	}
+}
+#endif
+
+static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
+				   struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_info *info;
+	int err;
+
+	if (! substream)
+		return;
+
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return;
+
+	err = snd_pcm_info(substream, info);
+	if (err < 0) {
+		snd_iprintf(buffer, "error %d\n", err);
+		kfree(info);
+		return;
+	}
+	snd_iprintf(buffer, "card: %d\n", info->card);
+	snd_iprintf(buffer, "device: %d\n", info->device);
+	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
+	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
+	snd_iprintf(buffer, "id: %s\n", info->id);
+	snd_iprintf(buffer, "name: %s\n", info->name);
+	snd_iprintf(buffer, "subname: %s\n", info->subname);
+	snd_iprintf(buffer, "class: %d\n", info->dev_class);
+	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
+	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
+	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
+	kfree(info);
+}
+
+static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
+					  struct snd_info_buffer *buffer)
+{
+	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
+			       buffer);
+}
+
+static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
+					     struct snd_info_buffer *buffer)
+{
+	snd_pcm_proc_info_read(entry->private_data, buffer);
+}
+
+static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
+						  struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	struct snd_pcm_runtime *runtime;
+
+	mutex_lock(&substream->pcm->open_mutex);
+	runtime = substream->runtime;
+	if (!runtime) {
+		snd_iprintf(buffer, "closed\n");
+		goto unlock;
+	}
+	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
+		snd_iprintf(buffer, "no setup\n");
+		goto unlock;
+	}
+	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
+	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
+	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
+	snd_iprintf(buffer, "channels: %u\n", runtime->channels);	
+	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);	
+	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);	
+	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);	
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+	if (substream->oss.oss) {
+		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
+		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);	
+		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
+		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
+		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
+		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
+	}
+#endif
+ unlock:
+	mutex_unlock(&substream->pcm->open_mutex);
+}
+
+static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
+						  struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	struct snd_pcm_runtime *runtime;
+
+	mutex_lock(&substream->pcm->open_mutex);
+	runtime = substream->runtime;
+	if (!runtime) {
+		snd_iprintf(buffer, "closed\n");
+		goto unlock;
+	}
+	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
+		snd_iprintf(buffer, "no setup\n");
+		goto unlock;
+	}
+	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
+	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
+	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
+	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
+	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
+	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
+	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
+	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
+ unlock:
+	mutex_unlock(&substream->pcm->open_mutex);
+}
+
+static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
+					       struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	struct snd_pcm_runtime *runtime;
+	struct snd_pcm_status64 status;
+	int err;
+
+	mutex_lock(&substream->pcm->open_mutex);
+	runtime = substream->runtime;
+	if (!runtime) {
+		snd_iprintf(buffer, "closed\n");
+		goto unlock;
+	}
+	memset(&status, 0, sizeof(status));
+	err = snd_pcm_status64(substream, &status);
+	if (err < 0) {
+		snd_iprintf(buffer, "error %d\n", err);
+		goto unlock;
+	}
+	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
+	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
+	snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
+		status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
+	snd_iprintf(buffer, "tstamp      : %lld.%09lld\n",
+		status.tstamp_sec, status.tstamp_nsec);
+	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
+	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
+	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
+	snd_iprintf(buffer, "-----\n");
+	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
+	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
+ unlock:
+	mutex_unlock(&substream->pcm->open_mutex);
+}
+
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
+					 struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+
+	snd_pcm_stop_xrun(substream);
+}
+
+static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
+				    struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_str *pstr = entry->private_data;
+	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
+}
+
+static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
+				     struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_str *pstr = entry->private_data;
+	char line[64];
+	if (!snd_info_get_line(buffer, line, sizeof(line)))
+		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
+}
+#endif
+
+static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
+{
+	struct snd_pcm *pcm = pstr->pcm;
+	struct snd_info_entry *entry;
+	char name[16];
+
+	sprintf(name, "pcm%i%c", pcm->device, 
+		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
+	entry = snd_info_create_card_entry(pcm->card, name,
+					   pcm->card->proc_root);
+	if (!entry)
+		return -ENOMEM;
+	entry->mode = S_IFDIR | 0555;
+	pstr->proc_root = entry;
+	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
+					   pstr->proc_root);
+	if (entry) {
+		snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
+		entry->c.text.write = snd_pcm_xrun_debug_write;
+		entry->mode |= 0200;
+	}
+#endif
+	return 0;
+}
+
+static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
+{
+	snd_info_free_entry(pstr->proc_root);
+	pstr->proc_root = NULL;
+	return 0;
+}
+
+static struct snd_info_entry *
+create_substream_info_entry(struct snd_pcm_substream *substream,
+			    const char *name,
+			    void (*read)(struct snd_info_entry *,
+					 struct snd_info_buffer *))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(substream->pcm->card, name,
+					   substream->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, substream, read);
+	return entry;
+}
+
+static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
+{
+	struct snd_info_entry *entry;
+	struct snd_card *card;
+	char name[16];
+
+	card = substream->pcm->card;
+
+	sprintf(name, "sub%i", substream->number);
+	entry = snd_info_create_card_entry(card, name,
+					   substream->pstr->proc_root);
+	if (!entry)
+		return -ENOMEM;
+	entry->mode = S_IFDIR | 0555;
+	substream->proc_root = entry;
+
+	create_substream_info_entry(substream, "info",
+				    snd_pcm_substream_proc_info_read);
+	create_substream_info_entry(substream, "hw_params",
+				    snd_pcm_substream_proc_hw_params_read);
+	create_substream_info_entry(substream, "sw_params",
+				    snd_pcm_substream_proc_sw_params_read);
+	create_substream_info_entry(substream, "status",
+				    snd_pcm_substream_proc_status_read);
+
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+	entry = create_substream_info_entry(substream, "xrun_injection", NULL);
+	if (entry) {
+		entry->c.text.write = snd_pcm_xrun_injection_write;
+		entry->mode = S_IFREG | 0200;
+	}
+#endif /* CONFIG_SND_PCM_XRUN_DEBUG */
+
+	return 0;
+}
+
+#else /* !CONFIG_SND_VERBOSE_PROCFS */
+static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
+static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
+static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
+#endif /* CONFIG_SND_VERBOSE_PROCFS */
+
+static const struct attribute_group *pcm_dev_attr_groups[];
+
+/*
+ * PM callbacks: we need to deal only with suspend here, as the resume is
+ * triggered either from user-space or the driver's resume callback
+ */
+#ifdef CONFIG_PM_SLEEP
+static int do_pcm_suspend(struct device *dev)
+{
+	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
+
+	if (!pstr->pcm->no_device_suspend)
+		snd_pcm_suspend_all(pstr->pcm);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops pcm_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
+};
+
+/* device type for PCM -- basically only for passing PM callbacks */
+static const struct device_type pcm_dev_type = {
+	.name = "pcm",
+	.pm = &pcm_dev_pm_ops,
+};
+
+/**
+ * snd_pcm_new_stream - create a new PCM stream
+ * @pcm: the pcm instance
+ * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
+ * @substream_count: the number of substreams
+ *
+ * Creates a new stream for the pcm.
+ * The corresponding stream on the pcm must have been empty before
+ * calling this, i.e. zero must be given to the argument of
+ * snd_pcm_new().
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
+{
+	int idx, err;
+	struct snd_pcm_str *pstr = &pcm->streams[stream];
+	struct snd_pcm_substream *substream, *prev;
+
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+	mutex_init(&pstr->oss.setup_mutex);
+#endif
+	pstr->stream = stream;
+	pstr->pcm = pcm;
+	pstr->substream_count = substream_count;
+	if (!substream_count)
+		return 0;
+
+	err = snd_device_alloc(&pstr->dev, pcm->card);
+	if (err < 0)
+		return err;
+	dev_set_name(pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
+		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
+	pstr->dev->groups = pcm_dev_attr_groups;
+	pstr->dev->type = &pcm_dev_type;
+	dev_set_drvdata(pstr->dev, pstr);
+
+	if (!pcm->internal) {
+		err = snd_pcm_stream_proc_init(pstr);
+		if (err < 0) {
+			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
+			return err;
+		}
+	}
+	prev = NULL;
+	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
+		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
+		if (!substream)
+			return -ENOMEM;
+		substream->pcm = pcm;
+		substream->pstr = pstr;
+		substream->number = idx;
+		substream->stream = stream;
+		sprintf(substream->name, "subdevice #%i", idx);
+		substream->buffer_bytes_max = UINT_MAX;
+		if (prev == NULL)
+			pstr->substream = substream;
+		else
+			prev->next = substream;
+
+		if (!pcm->internal) {
+			err = snd_pcm_substream_proc_init(substream);
+			if (err < 0) {
+				pcm_err(pcm,
+					"Error in snd_pcm_stream_proc_init\n");
+				if (prev == NULL)
+					pstr->substream = NULL;
+				else
+					prev->next = NULL;
+				kfree(substream);
+				return err;
+			}
+		}
+		substream->group = &substream->self_group;
+		snd_pcm_group_init(&substream->self_group);
+		list_add_tail(&substream->link_list, &substream->self_group.substreams);
+		atomic_set(&substream->mmap_count, 0);
+		prev = substream;
+	}
+	return 0;
+}				
+EXPORT_SYMBOL(snd_pcm_new_stream);
+
+static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
+		int playback_count, int capture_count, bool internal,
+		struct snd_pcm **rpcm)
+{
+	struct snd_pcm *pcm;
+	int err;
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_pcm_dev_free,
+		.dev_register =	snd_pcm_dev_register,
+		.dev_disconnect = snd_pcm_dev_disconnect,
+	};
+	static const struct snd_device_ops internal_ops = {
+		.dev_free = snd_pcm_dev_free,
+	};
+
+	if (snd_BUG_ON(!card))
+		return -ENXIO;
+	if (rpcm)
+		*rpcm = NULL;
+	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
+	if (!pcm)
+		return -ENOMEM;
+	pcm->card = card;
+	pcm->device = device;
+	pcm->internal = internal;
+	mutex_init(&pcm->open_mutex);
+	init_waitqueue_head(&pcm->open_wait);
+	INIT_LIST_HEAD(&pcm->list);
+	if (id)
+		strscpy(pcm->id, id, sizeof(pcm->id));
+
+	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
+				 playback_count);
+	if (err < 0)
+		goto free_pcm;
+
+	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
+	if (err < 0)
+		goto free_pcm;
+
+	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
+			     internal ? &internal_ops : &ops);
+	if (err < 0)
+		goto free_pcm;
+
+	if (rpcm)
+		*rpcm = pcm;
+	return 0;
+
+free_pcm:
+	snd_pcm_free(pcm);
+	return err;
+}
+
+/**
+ * snd_pcm_new - create a new PCM instance
+ * @card: the card instance
+ * @id: the id string
+ * @device: the device index (zero based)
+ * @playback_count: the number of substreams for playback
+ * @capture_count: the number of substreams for capture
+ * @rpcm: the pointer to store the new pcm instance
+ *
+ * Creates a new PCM instance.
+ *
+ * The pcm operators have to be set afterwards to the new instance
+ * via snd_pcm_set_ops().
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_new(struct snd_card *card, const char *id, int device,
+		int playback_count, int capture_count, struct snd_pcm **rpcm)
+{
+	return _snd_pcm_new(card, id, device, playback_count, capture_count,
+			false, rpcm);
+}
+EXPORT_SYMBOL(snd_pcm_new);
+
+/**
+ * snd_pcm_new_internal - create a new internal PCM instance
+ * @card: the card instance
+ * @id: the id string
+ * @device: the device index (zero based - shared with normal PCMs)
+ * @playback_count: the number of substreams for playback
+ * @capture_count: the number of substreams for capture
+ * @rpcm: the pointer to store the new pcm instance
+ *
+ * Creates a new internal PCM instance with no userspace device or procfs
+ * entries. This is used by ASoC Back End PCMs in order to create a PCM that
+ * will only be used internally by kernel drivers. i.e. it cannot be opened
+ * by userspace. It provides existing ASoC components drivers with a substream
+ * and access to any private data.
+ *
+ * The pcm operators have to be set afterwards to the new instance
+ * via snd_pcm_set_ops().
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
+	int playback_count, int capture_count,
+	struct snd_pcm **rpcm)
+{
+	return _snd_pcm_new(card, id, device, playback_count, capture_count,
+			true, rpcm);
+}
+EXPORT_SYMBOL(snd_pcm_new_internal);
+
+static void free_chmap(struct snd_pcm_str *pstr)
+{
+	if (pstr->chmap_kctl) {
+		struct snd_card *card = pstr->pcm->card;
+
+		snd_ctl_remove(card, pstr->chmap_kctl);
+		pstr->chmap_kctl = NULL;
+	}
+}
+
+static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
+{
+	struct snd_pcm_substream *substream, *substream_next;
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+	struct snd_pcm_oss_setup *setup, *setupn;
+#endif
+
+	/* free all proc files under the stream */
+	snd_pcm_stream_proc_done(pstr);
+
+	substream = pstr->substream;
+	while (substream) {
+		substream_next = substream->next;
+		snd_pcm_timer_done(substream);
+		kfree(substream);
+		substream = substream_next;
+	}
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
+		setupn = setup->next;
+		kfree(setup->task_name);
+		kfree(setup);
+	}
+#endif
+	free_chmap(pstr);
+	if (pstr->substream_count)
+		put_device(pstr->dev);
+}
+
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+#define pcm_call_notify(pcm, call)					\
+	do {								\
+		struct snd_pcm_notify *_notify;				\
+		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
+			_notify->call(pcm);				\
+	} while (0)
+#else
+#define pcm_call_notify(pcm, call) do {} while (0)
+#endif
+
+static int snd_pcm_free(struct snd_pcm *pcm)
+{
+	if (!pcm)
+		return 0;
+	if (!pcm->internal)
+		pcm_call_notify(pcm, n_unregister);
+	if (pcm->private_free)
+		pcm->private_free(pcm);
+	snd_pcm_lib_preallocate_free_for_all(pcm);
+	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
+	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
+	kfree(pcm);
+	return 0;
+}
+
+static int snd_pcm_dev_free(struct snd_device *device)
+{
+	struct snd_pcm *pcm = device->device_data;
+	return snd_pcm_free(pcm);
+}
+
+int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
+			     struct file *file,
+			     struct snd_pcm_substream **rsubstream)
+{
+	struct snd_pcm_str * pstr;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	struct snd_card *card;
+	int prefer_subdevice;
+	size_t size;
+
+	if (snd_BUG_ON(!pcm || !rsubstream))
+		return -ENXIO;
+	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
+		       stream != SNDRV_PCM_STREAM_CAPTURE))
+		return -EINVAL;
+	*rsubstream = NULL;
+	pstr = &pcm->streams[stream];
+	if (pstr->substream == NULL || pstr->substream_count == 0)
+		return -ENODEV;
+
+	card = pcm->card;
+	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
+
+	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
+		int opposite = !stream;
+
+		for (substream = pcm->streams[opposite].substream; substream;
+		     substream = substream->next) {
+			if (SUBSTREAM_BUSY(substream))
+				return -EAGAIN;
+		}
+	}
+
+	if (file->f_flags & O_APPEND) {
+		if (prefer_subdevice < 0) {
+			if (pstr->substream_count > 1)
+				return -EINVAL; /* must be unique */
+			substream = pstr->substream;
+		} else {
+			for (substream = pstr->substream; substream;
+			     substream = substream->next)
+				if (substream->number == prefer_subdevice)
+					break;
+		}
+		if (! substream)
+			return -ENODEV;
+		if (! SUBSTREAM_BUSY(substream))
+			return -EBADFD;
+		substream->ref_count++;
+		*rsubstream = substream;
+		return 0;
+	}
+
+	for (substream = pstr->substream; substream; substream = substream->next) {
+		if (!SUBSTREAM_BUSY(substream) &&
+		    (prefer_subdevice == -1 ||
+		     substream->number == prefer_subdevice))
+			break;
+	}
+	if (substream == NULL)
+		return -EAGAIN;
+
+	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
+	if (runtime == NULL)
+		return -ENOMEM;
+
+	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
+	runtime->status = alloc_pages_exact(size, GFP_KERNEL);
+	if (runtime->status == NULL) {
+		kfree(runtime);
+		return -ENOMEM;
+	}
+	memset(runtime->status, 0, size);
+
+	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
+	runtime->control = alloc_pages_exact(size, GFP_KERNEL);
+	if (runtime->control == NULL) {
+		free_pages_exact(runtime->status,
+			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
+		kfree(runtime);
+		return -ENOMEM;
+	}
+	memset(runtime->control, 0, size);
+
+	init_waitqueue_head(&runtime->sleep);
+	init_waitqueue_head(&runtime->tsleep);
+
+	__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
+	mutex_init(&runtime->buffer_mutex);
+	atomic_set(&runtime->buffer_accessing, 0);
+
+	substream->runtime = runtime;
+	substream->private_data = pcm->private_data;
+	substream->ref_count = 1;
+	substream->f_flags = file->f_flags;
+	substream->pid = get_pid(task_pid(current));
+	pstr->substream_opened++;
+	*rsubstream = substream;
+	return 0;
+}
+
+void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return;
+	runtime = substream->runtime;
+	if (runtime->private_free != NULL)
+		runtime->private_free(runtime);
+	free_pages_exact(runtime->status,
+		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
+	free_pages_exact(runtime->control,
+		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
+	kfree(runtime->hw_constraints.rules);
+	/* Avoid concurrent access to runtime via PCM timer interface */
+	if (substream->timer) {
+		spin_lock_irq(&substream->timer->lock);
+		substream->runtime = NULL;
+		spin_unlock_irq(&substream->timer->lock);
+	} else {
+		substream->runtime = NULL;
+	}
+	mutex_destroy(&runtime->buffer_mutex);
+	snd_fasync_free(runtime->fasync);
+	kfree(runtime);
+	put_pid(substream->pid);
+	substream->pid = NULL;
+	substream->pstr->substream_opened--;
+}
+
+static ssize_t pcm_class_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
+	struct snd_pcm *pcm = pstr->pcm;
+	const char *str;
+	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
+		[SNDRV_PCM_CLASS_GENERIC] = "generic",
+		[SNDRV_PCM_CLASS_MULTI] = "multi",
+		[SNDRV_PCM_CLASS_MODEM] = "modem",
+		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
+	};
+
+	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
+		str = "none";
+	else
+		str = strs[pcm->dev_class];
+	return sysfs_emit(buf, "%s\n", str);
+}
+
+static DEVICE_ATTR_RO(pcm_class);
+static struct attribute *pcm_dev_attrs[] = {
+	&dev_attr_pcm_class.attr,
+	NULL
+};
+
+static const struct attribute_group pcm_dev_attr_group = {
+	.attrs	= pcm_dev_attrs,
+};
+
+static const struct attribute_group *pcm_dev_attr_groups[] = {
+	&pcm_dev_attr_group,
+	NULL
+};
+
+static int snd_pcm_dev_register(struct snd_device *device)
+{
+	int cidx, err;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm *pcm;
+
+	if (snd_BUG_ON(!device || !device->device_data))
+		return -ENXIO;
+	pcm = device->device_data;
+
+	mutex_lock(&register_mutex);
+	err = snd_pcm_add(pcm);
+	if (err)
+		goto unlock;
+	for (cidx = 0; cidx < 2; cidx++) {
+		int devtype = -1;
+		if (pcm->streams[cidx].substream == NULL)
+			continue;
+		switch (cidx) {
+		case SNDRV_PCM_STREAM_PLAYBACK:
+			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
+			break;
+		case SNDRV_PCM_STREAM_CAPTURE:
+			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
+			break;
+		}
+		/* register pcm */
+		err = snd_register_device(devtype, pcm->card, pcm->device,
+					  &snd_pcm_f_ops[cidx], pcm,
+					  pcm->streams[cidx].dev);
+		if (err < 0) {
+			list_del_init(&pcm->list);
+			goto unlock;
+		}
+
+		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
+			snd_pcm_timer_init(substream);
+	}
+
+	pcm_call_notify(pcm, n_register);
+
+ unlock:
+	mutex_unlock(&register_mutex);
+	return err;
+}
+
+static int snd_pcm_dev_disconnect(struct snd_device *device)
+{
+	struct snd_pcm *pcm = device->device_data;
+	struct snd_pcm_substream *substream;
+	int cidx;
+
+	mutex_lock(&register_mutex);
+	mutex_lock(&pcm->open_mutex);
+	wake_up(&pcm->open_wait);
+	list_del_init(&pcm->list);
+
+	for_each_pcm_substream(pcm, cidx, substream) {
+		snd_pcm_stream_lock_irq(substream);
+		if (substream->runtime) {
+			if (snd_pcm_running(substream))
+				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
+			/* to be sure, set the state unconditionally */
+			__snd_pcm_set_state(substream->runtime,
+					    SNDRV_PCM_STATE_DISCONNECTED);
+			wake_up(&substream->runtime->sleep);
+			wake_up(&substream->runtime->tsleep);
+		}
+		snd_pcm_stream_unlock_irq(substream);
+	}
+
+	for_each_pcm_substream(pcm, cidx, substream)
+		snd_pcm_sync_stop(substream, false);
+
+	pcm_call_notify(pcm, n_disconnect);
+	for (cidx = 0; cidx < 2; cidx++) {
+		if (pcm->streams[cidx].dev)
+			snd_unregister_device(pcm->streams[cidx].dev);
+		free_chmap(&pcm->streams[cidx]);
+	}
+	mutex_unlock(&pcm->open_mutex);
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+/**
+ * snd_pcm_notify - Add/remove the notify list
+ * @notify: PCM notify list
+ * @nfree: 0 = register, 1 = unregister
+ *
+ * This adds the given notifier to the global list so that the callback is
+ * called for each registered PCM devices.  This exists only for PCM OSS
+ * emulation, so far.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
+{
+	struct snd_pcm *pcm;
+
+	if (snd_BUG_ON(!notify ||
+		       !notify->n_register ||
+		       !notify->n_unregister ||
+		       !notify->n_disconnect))
+		return -EINVAL;
+	mutex_lock(&register_mutex);
+	if (nfree) {
+		list_del(&notify->list);
+		list_for_each_entry(pcm, &snd_pcm_devices, list)
+			notify->n_unregister(pcm);
+	} else {
+		list_add_tail(&notify->list, &snd_pcm_notify_list);
+		list_for_each_entry(pcm, &snd_pcm_devices, list)
+			notify->n_register(pcm);
+	}
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_notify);
+#endif /* CONFIG_SND_PCM_OSS */
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ *  Info interface
+ */
+
+static void snd_pcm_proc_read(struct snd_info_entry *entry,
+			      struct snd_info_buffer *buffer)
+{
+	struct snd_pcm *pcm;
+
+	mutex_lock(&register_mutex);
+	list_for_each_entry(pcm, &snd_pcm_devices, list) {
+		snd_iprintf(buffer, "%02i-%02i: %s : %s",
+			    pcm->card->number, pcm->device, pcm->id, pcm->name);
+		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
+			snd_iprintf(buffer, " : playback %i",
+				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
+		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
+			snd_iprintf(buffer, " : capture %i",
+				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
+		snd_iprintf(buffer, "\n");
+	}
+	mutex_unlock(&register_mutex);
+}
+
+static struct snd_info_entry *snd_pcm_proc_entry;
+
+static void snd_pcm_proc_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
+	if (entry) {
+		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
+		if (snd_info_register(entry) < 0) {
+			snd_info_free_entry(entry);
+			entry = NULL;
+		}
+	}
+	snd_pcm_proc_entry = entry;
+}
+
+static void snd_pcm_proc_done(void)
+{
+	snd_info_free_entry(snd_pcm_proc_entry);
+}
+
+#else /* !CONFIG_SND_PROC_FS */
+#define snd_pcm_proc_init()
+#define snd_pcm_proc_done()
+#endif /* CONFIG_SND_PROC_FS */
+
+
+/*
+ *  ENTRY functions
+ */
+
+static int __init alsa_pcm_init(void)
+{
+	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
+	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
+	snd_pcm_proc_init();
+	return 0;
+}
+
+static void __exit alsa_pcm_exit(void)
+{
+	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
+	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
+	snd_pcm_proc_done();
+}
+
+module_init(alsa_pcm_init)
+module_exit(alsa_pcm_exit)
diff --git a/sound/core/pcm_compat.c b/sound/core/pcm_compat.c
new file mode 100644
index 0000000000..c96483091f
--- /dev/null
+++ b/sound/core/pcm_compat.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   32bit -> 64bit ioctl wrapper for PCM API
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ */
+
+/* This file included from pcm_native.c */
+
+#include <linux/compat.h>
+#include <linux/slab.h>
+
+static int snd_pcm_ioctl_delay_compat(struct snd_pcm_substream *substream,
+				      s32 __user *src)
+{
+	snd_pcm_sframes_t delay;
+	int err;
+
+	err = snd_pcm_delay(substream, &delay);
+	if (err)
+		return err;
+	if (put_user(delay, src))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_pcm_ioctl_rewind_compat(struct snd_pcm_substream *substream,
+				       u32 __user *src)
+{
+	snd_pcm_uframes_t frames;
+	int err;
+
+	if (get_user(frames, src))
+		return -EFAULT;
+	err = snd_pcm_rewind(substream, frames);
+	if (put_user(err, src))
+		return -EFAULT;
+	return err < 0 ? err : 0;
+}
+
+static int snd_pcm_ioctl_forward_compat(struct snd_pcm_substream *substream,
+				       u32 __user *src)
+{
+	snd_pcm_uframes_t frames;
+	int err;
+
+	if (get_user(frames, src))
+		return -EFAULT;
+	err = snd_pcm_forward(substream, frames);
+	if (put_user(err, src))
+		return -EFAULT;
+	return err < 0 ? err : 0;
+}
+
+struct snd_pcm_hw_params32 {
+	u32 flags;
+	struct snd_mask masks[SNDRV_PCM_HW_PARAM_LAST_MASK - SNDRV_PCM_HW_PARAM_FIRST_MASK + 1]; /* this must be identical */
+	struct snd_mask mres[5];	/* reserved masks */
+	struct snd_interval intervals[SNDRV_PCM_HW_PARAM_LAST_INTERVAL - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL + 1];
+	struct snd_interval ires[9];	/* reserved intervals */
+	u32 rmask;
+	u32 cmask;
+	u32 info;
+	u32 msbits;
+	u32 rate_num;
+	u32 rate_den;
+	u32 fifo_size;
+	unsigned char reserved[64];
+};
+
+struct snd_pcm_sw_params32 {
+	s32 tstamp_mode;
+	u32 period_step;
+	u32 sleep_min;
+	u32 avail_min;
+	u32 xfer_align;
+	u32 start_threshold;
+	u32 stop_threshold;
+	u32 silence_threshold;
+	u32 silence_size;
+	u32 boundary;
+	u32 proto;
+	u32 tstamp_type;
+	unsigned char reserved[56];
+};
+
+static int snd_pcm_ioctl_sw_params_compat(struct snd_pcm_substream *substream,
+					  struct snd_pcm_sw_params32 __user *src)
+{
+	struct snd_pcm_sw_params params;
+	snd_pcm_uframes_t boundary;
+	int err;
+
+	memset(&params, 0, sizeof(params));
+	if (get_user(params.tstamp_mode, &src->tstamp_mode) ||
+	    get_user(params.period_step, &src->period_step) ||
+	    get_user(params.sleep_min, &src->sleep_min) ||
+	    get_user(params.avail_min, &src->avail_min) ||
+	    get_user(params.xfer_align, &src->xfer_align) ||
+	    get_user(params.start_threshold, &src->start_threshold) ||
+	    get_user(params.stop_threshold, &src->stop_threshold) ||
+	    get_user(params.silence_threshold, &src->silence_threshold) ||
+	    get_user(params.silence_size, &src->silence_size) ||
+	    get_user(params.tstamp_type, &src->tstamp_type) ||
+	    get_user(params.proto, &src->proto))
+		return -EFAULT;
+	/*
+	 * Check silent_size parameter.  Since we have 64bit boundary,
+	 * silence_size must be compared with the 32bit boundary.
+	 */
+	boundary = recalculate_boundary(substream->runtime);
+	if (boundary && params.silence_size >= boundary)
+		params.silence_size = substream->runtime->boundary;
+	err = snd_pcm_sw_params(substream, &params);
+	if (err < 0)
+		return err;
+	if (boundary && put_user(boundary, &src->boundary))
+		return -EFAULT;
+	return err;
+}
+
+struct snd_pcm_channel_info32 {
+	u32 channel;
+	u32 offset;
+	u32 first;
+	u32 step;
+};
+
+static int snd_pcm_ioctl_channel_info_compat(struct snd_pcm_substream *substream,
+					     struct snd_pcm_channel_info32 __user *src)
+{
+	struct snd_pcm_channel_info info;
+	int err;
+
+	if (get_user(info.channel, &src->channel) ||
+	    get_user(info.offset, &src->offset) ||
+	    get_user(info.first, &src->first) ||
+	    get_user(info.step, &src->step))
+		return -EFAULT;
+	err = snd_pcm_channel_info(substream, &info);
+	if (err < 0)
+		return err;
+	if (put_user(info.channel, &src->channel) ||
+	    put_user(info.offset, &src->offset) ||
+	    put_user(info.first, &src->first) ||
+	    put_user(info.step, &src->step))
+		return -EFAULT;
+	return err;
+}
+
+#ifdef CONFIG_X86_X32_ABI
+/* X32 ABI has the same struct as x86-64 for snd_pcm_channel_info */
+static int snd_pcm_channel_info_user(struct snd_pcm_substream *substream,
+				     struct snd_pcm_channel_info __user *src);
+#define snd_pcm_ioctl_channel_info_x32(s, p)	\
+	snd_pcm_channel_info_user(s, p)
+#endif /* CONFIG_X86_X32_ABI */
+
+struct compat_snd_pcm_status64 {
+	snd_pcm_state_t state;
+	u8 rsvd[4]; /* alignment */
+	s64 trigger_tstamp_sec;
+	s64 trigger_tstamp_nsec;
+	s64 tstamp_sec;
+	s64 tstamp_nsec;
+	u32 appl_ptr;
+	u32 hw_ptr;
+	s32 delay;
+	u32 avail;
+	u32 avail_max;
+	u32 overrange;
+	snd_pcm_state_t suspended_state;
+	u32 audio_tstamp_data;
+	s64 audio_tstamp_sec;
+	s64 audio_tstamp_nsec;
+	s64 driver_tstamp_sec;
+	s64 driver_tstamp_nsec;
+	u32 audio_tstamp_accuracy;
+	unsigned char reserved[52-4*sizeof(s64)];
+} __packed;
+
+static int snd_pcm_status_user_compat64(struct snd_pcm_substream *substream,
+					struct compat_snd_pcm_status64 __user *src,
+					bool ext)
+{
+	struct snd_pcm_status64 status;
+	struct compat_snd_pcm_status64 compat_status64;
+	int err;
+
+	memset(&status, 0, sizeof(status));
+	memset(&compat_status64, 0, sizeof(compat_status64));
+	/*
+	 * with extension, parameters are read/write,
+	 * get audio_tstamp_data from user,
+	 * ignore rest of status structure
+	 */
+	if (ext && get_user(status.audio_tstamp_data,
+				(u32 __user *)(&src->audio_tstamp_data)))
+		return -EFAULT;
+	err = snd_pcm_status64(substream, &status);
+	if (err < 0)
+		return err;
+
+	if (clear_user(src, sizeof(*src)))
+		return -EFAULT;
+
+	compat_status64 = (struct compat_snd_pcm_status64) {
+		.state = status.state,
+		.trigger_tstamp_sec = status.trigger_tstamp_sec,
+		.trigger_tstamp_nsec = status.trigger_tstamp_nsec,
+		.tstamp_sec = status.tstamp_sec,
+		.tstamp_nsec = status.tstamp_nsec,
+		.appl_ptr = status.appl_ptr,
+		.hw_ptr = status.hw_ptr,
+		.delay = status.delay,
+		.avail = status.avail,
+		.avail_max = status.avail_max,
+		.overrange = status.overrange,
+		.suspended_state = status.suspended_state,
+		.audio_tstamp_data = status.audio_tstamp_data,
+		.audio_tstamp_sec = status.audio_tstamp_sec,
+		.audio_tstamp_nsec = status.audio_tstamp_nsec,
+		.driver_tstamp_sec = status.audio_tstamp_sec,
+		.driver_tstamp_nsec = status.audio_tstamp_nsec,
+		.audio_tstamp_accuracy = status.audio_tstamp_accuracy,
+	};
+
+	if (copy_to_user(src, &compat_status64, sizeof(compat_status64)))
+		return -EFAULT;
+
+	return err;
+}
+
+/* both for HW_PARAMS and HW_REFINE */
+static int snd_pcm_ioctl_hw_params_compat(struct snd_pcm_substream *substream,
+					  int refine, 
+					  struct snd_pcm_hw_params32 __user *data32)
+{
+	struct snd_pcm_hw_params *data;
+	struct snd_pcm_runtime *runtime;
+	int err;
+
+	runtime = substream->runtime;
+	if (!runtime)
+		return -ENOTTY;
+
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* only fifo_size (RO from userspace) is different, so just copy all */
+	if (copy_from_user(data, data32, sizeof(*data32))) {
+		err = -EFAULT;
+		goto error;
+	}
+
+	if (refine) {
+		err = snd_pcm_hw_refine(substream, data);
+		if (err < 0)
+			goto error;
+		err = fixup_unreferenced_params(substream, data);
+	} else {
+		err = snd_pcm_hw_params(substream, data);
+	}
+	if (err < 0)
+		goto error;
+	if (copy_to_user(data32, data, sizeof(*data32)) ||
+	    put_user(data->fifo_size, &data32->fifo_size)) {
+		err = -EFAULT;
+		goto error;
+	}
+
+	if (! refine) {
+		unsigned int new_boundary = recalculate_boundary(runtime);
+		if (new_boundary)
+			runtime->boundary = new_boundary;
+	}
+ error:
+	kfree(data);
+	return err;
+}
+
+
+/*
+ */
+struct snd_xferi32 {
+	s32 result;
+	u32 buf;
+	u32 frames;
+};
+
+static int snd_pcm_ioctl_xferi_compat(struct snd_pcm_substream *substream,
+				      int dir, struct snd_xferi32 __user *data32)
+{
+	compat_caddr_t buf;
+	u32 frames;
+	int err;
+
+	if (! substream->runtime)
+		return -ENOTTY;
+	if (substream->stream != dir)
+		return -EINVAL;
+	if (substream->runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+
+	if (get_user(buf, &data32->buf) ||
+	    get_user(frames, &data32->frames))
+		return -EFAULT;
+
+	if (dir == SNDRV_PCM_STREAM_PLAYBACK)
+		err = snd_pcm_lib_write(substream, compat_ptr(buf), frames);
+	else
+		err = snd_pcm_lib_read(substream, compat_ptr(buf), frames);
+	if (err < 0)
+		return err;
+	/* copy the result */
+	if (put_user(err, &data32->result))
+		return -EFAULT;
+	return 0;
+}
+
+
+/* snd_xfern needs remapping of bufs */
+struct snd_xfern32 {
+	s32 result;
+	u32 bufs;  /* this is void **; */
+	u32 frames;
+};
+
+/*
+ * xfern ioctl nees to copy (up to) 128 pointers on stack.
+ * although we may pass the copied pointers through f_op->ioctl, but the ioctl
+ * handler there expands again the same 128 pointers on stack, so it is better
+ * to handle the function (calling pcm_readv/writev) directly in this handler.
+ */
+static int snd_pcm_ioctl_xfern_compat(struct snd_pcm_substream *substream,
+				      int dir, struct snd_xfern32 __user *data32)
+{
+	compat_caddr_t buf;
+	compat_caddr_t __user *bufptr;
+	u32 frames;
+	void __user **bufs;
+	int err, ch, i;
+
+	if (! substream->runtime)
+		return -ENOTTY;
+	if (substream->stream != dir)
+		return -EINVAL;
+	if (substream->runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+
+	ch = substream->runtime->channels;
+	if (ch > 128)
+		return -EINVAL;
+	if (get_user(buf, &data32->bufs) ||
+	    get_user(frames, &data32->frames))
+		return -EFAULT;
+	bufptr = compat_ptr(buf);
+	bufs = kmalloc_array(ch, sizeof(void __user *), GFP_KERNEL);
+	if (bufs == NULL)
+		return -ENOMEM;
+	for (i = 0; i < ch; i++) {
+		u32 ptr;
+		if (get_user(ptr, bufptr)) {
+			kfree(bufs);
+			return -EFAULT;
+		}
+		bufs[i] = compat_ptr(ptr);
+		bufptr++;
+	}
+	if (dir == SNDRV_PCM_STREAM_PLAYBACK)
+		err = snd_pcm_lib_writev(substream, bufs, frames);
+	else
+		err = snd_pcm_lib_readv(substream, bufs, frames);
+	if (err >= 0) {
+		if (put_user(err, &data32->result))
+			err = -EFAULT;
+	}
+	kfree(bufs);
+	return err;
+}
+
+#ifdef CONFIG_X86_X32_ABI
+/* X32 ABI has 64bit timespec and 64bit alignment */
+struct snd_pcm_mmap_status_x32 {
+	snd_pcm_state_t state;
+	s32 pad1;
+	u32 hw_ptr;
+	u32 pad2; /* alignment */
+	s64 tstamp_sec;
+	s64 tstamp_nsec;
+	snd_pcm_state_t suspended_state;
+	s32 pad3;
+	s64 audio_tstamp_sec;
+	s64 audio_tstamp_nsec;
+} __packed;
+
+struct snd_pcm_mmap_control_x32 {
+	u32 appl_ptr;
+	u32 avail_min;
+};
+
+struct snd_pcm_sync_ptr_x32 {
+	u32 flags;
+	u32 rsvd; /* alignment */
+	union {
+		struct snd_pcm_mmap_status_x32 status;
+		unsigned char reserved[64];
+	} s;
+	union {
+		struct snd_pcm_mmap_control_x32 control;
+		unsigned char reserved[64];
+	} c;
+} __packed;
+
+static int snd_pcm_ioctl_sync_ptr_x32(struct snd_pcm_substream *substream,
+				      struct snd_pcm_sync_ptr_x32 __user *src)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	volatile struct snd_pcm_mmap_status *status;
+	volatile struct snd_pcm_mmap_control *control;
+	u32 sflags;
+	struct snd_pcm_mmap_control scontrol;
+	struct snd_pcm_mmap_status sstatus;
+	snd_pcm_uframes_t boundary;
+	int err;
+
+	if (snd_BUG_ON(!runtime))
+		return -EINVAL;
+
+	if (get_user(sflags, &src->flags) ||
+	    get_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
+	    get_user(scontrol.avail_min, &src->c.control.avail_min))
+		return -EFAULT;
+	if (sflags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
+		err = snd_pcm_hwsync(substream);
+		if (err < 0)
+			return err;
+	}
+	status = runtime->status;
+	control = runtime->control;
+	boundary = recalculate_boundary(runtime);
+	if (!boundary)
+		boundary = 0x7fffffff;
+	snd_pcm_stream_lock_irq(substream);
+	/* FIXME: we should consider the boundary for the sync from app */
+	if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL))
+		control->appl_ptr = scontrol.appl_ptr;
+	else
+		scontrol.appl_ptr = control->appl_ptr % boundary;
+	if (!(sflags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
+		control->avail_min = scontrol.avail_min;
+	else
+		scontrol.avail_min = control->avail_min;
+	sstatus.state = status->state;
+	sstatus.hw_ptr = status->hw_ptr % boundary;
+	sstatus.tstamp = status->tstamp;
+	sstatus.suspended_state = status->suspended_state;
+	sstatus.audio_tstamp = status->audio_tstamp;
+	snd_pcm_stream_unlock_irq(substream);
+	if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL))
+		snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+	if (put_user(sstatus.state, &src->s.status.state) ||
+	    put_user(sstatus.hw_ptr, &src->s.status.hw_ptr) ||
+	    put_user(sstatus.tstamp.tv_sec, &src->s.status.tstamp_sec) ||
+	    put_user(sstatus.tstamp.tv_nsec, &src->s.status.tstamp_nsec) ||
+	    put_user(sstatus.suspended_state, &src->s.status.suspended_state) ||
+	    put_user(sstatus.audio_tstamp.tv_sec, &src->s.status.audio_tstamp_sec) ||
+	    put_user(sstatus.audio_tstamp.tv_nsec, &src->s.status.audio_tstamp_nsec) ||
+	    put_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
+	    put_user(scontrol.avail_min, &src->c.control.avail_min))
+		return -EFAULT;
+
+	return 0;
+}
+#endif /* CONFIG_X86_X32_ABI */
+
+#ifdef __BIG_ENDIAN
+typedef char __pad_before_u32[4];
+typedef char __pad_after_u32[0];
+#else
+typedef char __pad_before_u32[0];
+typedef char __pad_after_u32[4];
+#endif
+
+/* PCM 2.0.15 API definition had a bug in mmap control; it puts the avail_min
+ * at the wrong offset due to a typo in padding type.
+ * The bug hits only 32bit.
+ * A workaround for incorrect read/write is needed only in 32bit compat mode.
+ */
+struct __snd_pcm_mmap_control64_buggy {
+	__pad_before_u32 __pad1;
+	__u32 appl_ptr;
+	__pad_before_u32 __pad2;	/* SiC! here is the bug */
+	__pad_before_u32 __pad3;
+	__u32 avail_min;
+	__pad_after_uframe __pad4;
+};
+
+static int snd_pcm_ioctl_sync_ptr_buggy(struct snd_pcm_substream *substream,
+					struct snd_pcm_sync_ptr __user *_sync_ptr)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_sync_ptr sync_ptr;
+	struct __snd_pcm_mmap_control64_buggy *sync_cp;
+	volatile struct snd_pcm_mmap_status *status;
+	volatile struct snd_pcm_mmap_control *control;
+	int err;
+
+	memset(&sync_ptr, 0, sizeof(sync_ptr));
+	sync_cp = (struct __snd_pcm_mmap_control64_buggy *)&sync_ptr.c.control;
+	if (get_user(sync_ptr.flags, (unsigned __user *)&(_sync_ptr->flags)))
+		return -EFAULT;
+	if (copy_from_user(sync_cp, &(_sync_ptr->c.control), sizeof(*sync_cp)))
+		return -EFAULT;
+	status = runtime->status;
+	control = runtime->control;
+	if (sync_ptr.flags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
+		err = snd_pcm_hwsync(substream);
+		if (err < 0)
+			return err;
+	}
+	snd_pcm_stream_lock_irq(substream);
+	if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL)) {
+		err = pcm_lib_apply_appl_ptr(substream, sync_cp->appl_ptr);
+		if (err < 0) {
+			snd_pcm_stream_unlock_irq(substream);
+			return err;
+		}
+	} else {
+		sync_cp->appl_ptr = control->appl_ptr;
+	}
+	if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
+		control->avail_min = sync_cp->avail_min;
+	else
+		sync_cp->avail_min = control->avail_min;
+	sync_ptr.s.status.state = status->state;
+	sync_ptr.s.status.hw_ptr = status->hw_ptr;
+	sync_ptr.s.status.tstamp = status->tstamp;
+	sync_ptr.s.status.suspended_state = status->suspended_state;
+	sync_ptr.s.status.audio_tstamp = status->audio_tstamp;
+	snd_pcm_stream_unlock_irq(substream);
+	if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL))
+		snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+	if (copy_to_user(_sync_ptr, &sync_ptr, sizeof(sync_ptr)))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ */
+enum {
+	SNDRV_PCM_IOCTL_HW_REFINE32 = _IOWR('A', 0x10, struct snd_pcm_hw_params32),
+	SNDRV_PCM_IOCTL_HW_PARAMS32 = _IOWR('A', 0x11, struct snd_pcm_hw_params32),
+	SNDRV_PCM_IOCTL_SW_PARAMS32 = _IOWR('A', 0x13, struct snd_pcm_sw_params32),
+	SNDRV_PCM_IOCTL_STATUS_COMPAT32 = _IOR('A', 0x20, struct snd_pcm_status32),
+	SNDRV_PCM_IOCTL_STATUS_EXT_COMPAT32 = _IOWR('A', 0x24, struct snd_pcm_status32),
+	SNDRV_PCM_IOCTL_DELAY32 = _IOR('A', 0x21, s32),
+	SNDRV_PCM_IOCTL_CHANNEL_INFO32 = _IOR('A', 0x32, struct snd_pcm_channel_info32),
+	SNDRV_PCM_IOCTL_REWIND32 = _IOW('A', 0x46, u32),
+	SNDRV_PCM_IOCTL_FORWARD32 = _IOW('A', 0x49, u32),
+	SNDRV_PCM_IOCTL_WRITEI_FRAMES32 = _IOW('A', 0x50, struct snd_xferi32),
+	SNDRV_PCM_IOCTL_READI_FRAMES32 = _IOR('A', 0x51, struct snd_xferi32),
+	SNDRV_PCM_IOCTL_WRITEN_FRAMES32 = _IOW('A', 0x52, struct snd_xfern32),
+	SNDRV_PCM_IOCTL_READN_FRAMES32 = _IOR('A', 0x53, struct snd_xfern32),
+	SNDRV_PCM_IOCTL_STATUS_COMPAT64 = _IOR('A', 0x20, struct compat_snd_pcm_status64),
+	SNDRV_PCM_IOCTL_STATUS_EXT_COMPAT64 = _IOWR('A', 0x24, struct compat_snd_pcm_status64),
+#ifdef CONFIG_X86_X32_ABI
+	SNDRV_PCM_IOCTL_CHANNEL_INFO_X32 = _IOR('A', 0x32, struct snd_pcm_channel_info),
+	SNDRV_PCM_IOCTL_SYNC_PTR_X32 = _IOWR('A', 0x23, struct snd_pcm_sync_ptr_x32),
+#endif /* CONFIG_X86_X32_ABI */
+};
+
+static long snd_pcm_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	void __user *argp = compat_ptr(arg);
+
+	pcm_file = file->private_data;
+	if (! pcm_file)
+		return -ENOTTY;
+	substream = pcm_file->substream;
+	if (! substream)
+		return -ENOTTY;
+
+	/*
+	 * When PCM is used on 32bit mode, we need to disable
+	 * mmap of the old PCM status/control records because
+	 * of the size incompatibility.
+	 */
+	pcm_file->no_compat_mmap = 1;
+
+	switch (cmd) {
+	case SNDRV_PCM_IOCTL_PVERSION:
+	case SNDRV_PCM_IOCTL_INFO:
+	case SNDRV_PCM_IOCTL_TSTAMP:
+	case SNDRV_PCM_IOCTL_TTSTAMP:
+	case SNDRV_PCM_IOCTL_USER_PVERSION:
+	case SNDRV_PCM_IOCTL_HWSYNC:
+	case SNDRV_PCM_IOCTL_PREPARE:
+	case SNDRV_PCM_IOCTL_RESET:
+	case SNDRV_PCM_IOCTL_START:
+	case SNDRV_PCM_IOCTL_DROP:
+	case SNDRV_PCM_IOCTL_DRAIN:
+	case SNDRV_PCM_IOCTL_PAUSE:
+	case SNDRV_PCM_IOCTL_HW_FREE:
+	case SNDRV_PCM_IOCTL_RESUME:
+	case SNDRV_PCM_IOCTL_XRUN:
+	case SNDRV_PCM_IOCTL_LINK:
+	case SNDRV_PCM_IOCTL_UNLINK:
+	case __SNDRV_PCM_IOCTL_SYNC_PTR32:
+		return snd_pcm_common_ioctl(file, substream, cmd, argp);
+	case __SNDRV_PCM_IOCTL_SYNC_PTR64:
+#ifdef CONFIG_X86_X32_ABI
+		if (in_x32_syscall())
+			return snd_pcm_ioctl_sync_ptr_x32(substream, argp);
+#endif /* CONFIG_X86_X32_ABI */
+		return snd_pcm_ioctl_sync_ptr_buggy(substream, argp);
+	case SNDRV_PCM_IOCTL_HW_REFINE32:
+		return snd_pcm_ioctl_hw_params_compat(substream, 1, argp);
+	case SNDRV_PCM_IOCTL_HW_PARAMS32:
+		return snd_pcm_ioctl_hw_params_compat(substream, 0, argp);
+	case SNDRV_PCM_IOCTL_SW_PARAMS32:
+		return snd_pcm_ioctl_sw_params_compat(substream, argp);
+	case SNDRV_PCM_IOCTL_STATUS_COMPAT32:
+		return snd_pcm_status_user32(substream, argp, false);
+	case SNDRV_PCM_IOCTL_STATUS_EXT_COMPAT32:
+		return snd_pcm_status_user32(substream, argp, true);
+	case SNDRV_PCM_IOCTL_CHANNEL_INFO32:
+		return snd_pcm_ioctl_channel_info_compat(substream, argp);
+	case SNDRV_PCM_IOCTL_WRITEI_FRAMES32:
+		return snd_pcm_ioctl_xferi_compat(substream, SNDRV_PCM_STREAM_PLAYBACK, argp);
+	case SNDRV_PCM_IOCTL_READI_FRAMES32:
+		return snd_pcm_ioctl_xferi_compat(substream, SNDRV_PCM_STREAM_CAPTURE, argp);
+	case SNDRV_PCM_IOCTL_WRITEN_FRAMES32:
+		return snd_pcm_ioctl_xfern_compat(substream, SNDRV_PCM_STREAM_PLAYBACK, argp);
+	case SNDRV_PCM_IOCTL_READN_FRAMES32:
+		return snd_pcm_ioctl_xfern_compat(substream, SNDRV_PCM_STREAM_CAPTURE, argp);
+	case SNDRV_PCM_IOCTL_DELAY32:
+		return snd_pcm_ioctl_delay_compat(substream, argp);
+	case SNDRV_PCM_IOCTL_REWIND32:
+		return snd_pcm_ioctl_rewind_compat(substream, argp);
+	case SNDRV_PCM_IOCTL_FORWARD32:
+		return snd_pcm_ioctl_forward_compat(substream, argp);
+	case SNDRV_PCM_IOCTL_STATUS_COMPAT64:
+		return snd_pcm_status_user_compat64(substream, argp, false);
+	case SNDRV_PCM_IOCTL_STATUS_EXT_COMPAT64:
+		return snd_pcm_status_user_compat64(substream, argp, true);
+#ifdef CONFIG_X86_X32_ABI
+	case SNDRV_PCM_IOCTL_CHANNEL_INFO_X32:
+		return snd_pcm_ioctl_channel_info_x32(substream, argp);
+#endif /* CONFIG_X86_X32_ABI */
+	}
+
+	return -ENOIOCTLCMD;
+}
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
new file mode 100644
index 0000000000..494ec0c207
--- /dev/null
+++ b/sound/core/pcm_dmaengine.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2012, Analog Devices Inc.
+ *	Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  Based on:
+ *	imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
+ *	mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
+ *	ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *		      Copyright (C) 2006 Applied Data Systems
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/dmaengine.h>
+#include <linux/slab.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <sound/dmaengine_pcm.h>
+
+struct dmaengine_pcm_runtime_data {
+	struct dma_chan *dma_chan;
+	dma_cookie_t cookie;
+
+	unsigned int pos;
+};
+
+static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
+	const struct snd_pcm_substream *substream)
+{
+	return substream->runtime->private_data;
+}
+
+struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	return prtd->dma_chan;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
+
+/**
+ * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
+ * @substream: PCM substream
+ * @params: hw_params
+ * @slave_config: DMA slave config
+ *
+ * This function can be used to initialize a dma_slave_config from a substream
+ * and hw_params in a dmaengine based PCM driver implementation.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
+	const struct snd_pcm_hw_params *params,
+	struct dma_slave_config *slave_config)
+{
+	enum dma_slave_buswidth buswidth;
+	int bits;
+
+	bits = params_physical_width(params);
+	if (bits < 8 || bits > 64)
+		return -EINVAL;
+	else if (bits == 8)
+		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	else if (bits == 16)
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	else if (bits == 24)
+		buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
+	else if (bits <= 32)
+		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	else
+		buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		slave_config->direction = DMA_MEM_TO_DEV;
+		slave_config->dst_addr_width = buswidth;
+	} else {
+		slave_config->direction = DMA_DEV_TO_MEM;
+		slave_config->src_addr_width = buswidth;
+	}
+
+	slave_config->device_fc = false;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
+
+/**
+ * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
+ *  using DAI DMA data.
+ * @substream: PCM substream
+ * @dma_data: DAI DMA data
+ * @slave_config: DMA slave configuration
+ *
+ * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width
+ * fields of the DMA slave config from the same fields of the DAI DMA
+ * data struct. The src and dst fields will be initialized depending on the
+ * direction of the substream. If the substream is a playback stream the dst
+ * fields will be initialized, if it is a capture stream the src fields will be
+ * initialized. The {dst,src}_addr_width field will only be initialized if the
+ * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
+ * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
+ * both conditions are met the latter takes priority.
+ */
+void snd_dmaengine_pcm_set_config_from_dai_data(
+	const struct snd_pcm_substream *substream,
+	const struct snd_dmaengine_dai_dma_data *dma_data,
+	struct dma_slave_config *slave_config)
+{
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		slave_config->dst_addr = dma_data->addr;
+		slave_config->dst_maxburst = dma_data->maxburst;
+		if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
+			slave_config->dst_addr_width =
+				DMA_SLAVE_BUSWIDTH_UNDEFINED;
+		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
+			slave_config->dst_addr_width = dma_data->addr_width;
+	} else {
+		slave_config->src_addr = dma_data->addr;
+		slave_config->src_maxburst = dma_data->maxburst;
+		if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
+			slave_config->src_addr_width =
+				DMA_SLAVE_BUSWIDTH_UNDEFINED;
+		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
+			slave_config->src_addr_width = dma_data->addr_width;
+	}
+
+	slave_config->peripheral_config = dma_data->peripheral_config;
+	slave_config->peripheral_size = dma_data->peripheral_size;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
+
+static void dmaengine_pcm_dma_complete(void *arg)
+{
+	unsigned int new_pos;
+	struct snd_pcm_substream *substream = arg;
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
+	if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
+		new_pos = 0;
+	prtd->pos = new_pos;
+
+	snd_pcm_period_elapsed(substream);
+}
+
+static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct dma_chan *chan = prtd->dma_chan;
+	struct dma_async_tx_descriptor *desc;
+	enum dma_transfer_direction direction;
+	unsigned long flags = DMA_CTRL_ACK;
+
+	direction = snd_pcm_substream_to_dma_direction(substream);
+
+	if (!substream->runtime->no_period_wakeup)
+		flags |= DMA_PREP_INTERRUPT;
+
+	prtd->pos = 0;
+	desc = dmaengine_prep_dma_cyclic(chan,
+		substream->runtime->dma_addr,
+		snd_pcm_lib_buffer_bytes(substream),
+		snd_pcm_lib_period_bytes(substream), direction, flags);
+
+	if (!desc)
+		return -ENOMEM;
+
+	desc->callback = dmaengine_pcm_dma_complete;
+	desc->callback_param = substream;
+	prtd->cookie = dmaengine_submit(desc);
+
+	return 0;
+}
+
+/**
+ * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
+ * @substream: PCM substream
+ * @cmd: Trigger command
+ *
+ * This function can be used as the PCM trigger callback for dmaengine based PCM
+ * driver implementations.
+ *
+ * Return: 0 on success, a negative error code otherwise
+ */
+int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int ret;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		ret = dmaengine_pcm_prepare_and_submit(substream);
+		if (ret)
+			return ret;
+		dma_async_issue_pending(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		dmaengine_resume(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		if (runtime->info & SNDRV_PCM_INFO_PAUSE)
+			dmaengine_pause(prtd->dma_chan);
+		else
+			dmaengine_terminate_async(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		dmaengine_pause(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		dmaengine_terminate_async(prtd->dma_chan);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
+
+/**
+ * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
+ * @substream: PCM substream
+ *
+ * This function is deprecated and should not be used by new drivers, as its
+ * results may be unreliable.
+ *
+ * Return: PCM position in frames
+ */
+snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	return bytes_to_frames(substream->runtime, prtd->pos);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
+
+/**
+ * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
+ * @substream: PCM substream
+ *
+ * This function can be used as the PCM pointer callback for dmaengine based PCM
+ * driver implementations.
+ *
+ * Return: PCM position in frames
+ */
+snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct dma_tx_state state;
+	enum dma_status status;
+	unsigned int buf_size;
+	unsigned int pos = 0;
+
+	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
+	if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
+		buf_size = snd_pcm_lib_buffer_bytes(substream);
+		if (state.residue > 0 && state.residue <= buf_size)
+			pos = buf_size - state.residue;
+
+		runtime->delay = bytes_to_frames(runtime,
+						 state.in_flight_bytes);
+	}
+
+	return bytes_to_frames(runtime, pos);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
+
+/**
+ * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
+ * @filter_fn: Filter function used to request the DMA channel
+ * @filter_data: Data passed to the DMA filter function
+ *
+ * This function request a DMA channel for usage with dmaengine PCM.
+ *
+ * Return: NULL or the requested DMA channel
+ */
+struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
+	void *filter_data)
+{
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_CYCLIC, mask);
+
+	return dma_request_channel(mask, filter_fn, filter_data);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
+
+/**
+ * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
+ * @substream: PCM substream
+ * @chan: DMA channel to use for data transfers
+ *
+ * The function should usually be called from the pcm open callback. Note that
+ * this function will use private_data field of the substream's runtime. So it
+ * is not available to your pcm driver implementation.
+ *
+ * Return: 0 on success, a negative error code otherwise
+ */
+int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
+	struct dma_chan *chan)
+{
+	struct dmaengine_pcm_runtime_data *prtd;
+	int ret;
+
+	if (!chan)
+		return -ENXIO;
+
+	ret = snd_pcm_hw_constraint_integer(substream->runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		return ret;
+
+	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
+	if (!prtd)
+		return -ENOMEM;
+
+	prtd->dma_chan = chan;
+
+	substream->runtime->private_data = prtd;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
+
+/**
+ * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
+ * @substream: PCM substream
+ * @filter_fn: Filter function used to request the DMA channel
+ * @filter_data: Data passed to the DMA filter function
+ *
+ * This function will request a DMA channel using the passed filter function and
+ * data. The function should usually be called from the pcm open callback. Note
+ * that this function will use private_data field of the substream's runtime. So
+ * it is not available to your pcm driver implementation.
+ *
+ * Return: 0 on success, a negative error code otherwise
+ */
+int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
+	dma_filter_fn filter_fn, void *filter_data)
+{
+	return snd_dmaengine_pcm_open(substream,
+		    snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
+
+/**
+ * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
+ * @substream: PCM substream
+ *
+ * Return: 0 on success, a negative error code otherwise
+ */
+int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	dmaengine_synchronize(prtd->dma_chan);
+	kfree(prtd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
+
+/**
+ * snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM
+ *					  substream and release channel
+ * @substream: PCM substream
+ *
+ * Releases the DMA channel associated with the PCM substream.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	dmaengine_synchronize(prtd->dma_chan);
+	dma_release_channel(prtd->dma_chan);
+	kfree(prtd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
+
+/**
+ * snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params
+ * @substream: PCM substream
+ * @dma_data: DAI DMA data
+ * @hw: PCM hw params
+ * @chan: DMA channel to use for data transfers
+ *
+ * This function will query DMA capability, then refine the pcm hardware
+ * parameters.
+ *
+ * Return: 0 on success, a negative error code otherwise
+ */
+int snd_dmaengine_pcm_refine_runtime_hwparams(
+	struct snd_pcm_substream *substream,
+	struct snd_dmaengine_dai_dma_data *dma_data,
+	struct snd_pcm_hardware *hw,
+	struct dma_chan *chan)
+{
+	struct dma_slave_caps dma_caps;
+	u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+			  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+			  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	snd_pcm_format_t i;
+	int ret = 0;
+
+	if (!hw || !chan || !dma_data)
+		return -EINVAL;
+
+	ret = dma_get_slave_caps(chan, &dma_caps);
+	if (ret == 0) {
+		if (dma_caps.cmd_pause && dma_caps.cmd_resume)
+			hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
+		if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
+			hw->info |= SNDRV_PCM_INFO_BATCH;
+
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			addr_widths = dma_caps.dst_addr_widths;
+		else
+			addr_widths = dma_caps.src_addr_widths;
+	}
+
+	/*
+	 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
+	 * hw.formats set to 0, meaning no restrictions are in place.
+	 * In this case it's the responsibility of the DAI driver to
+	 * provide the supported format information.
+	 */
+	if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
+		/*
+		 * Prepare formats mask for valid/allowed sample types. If the
+		 * dma does not have support for the given physical word size,
+		 * it needs to be masked out so user space can not use the
+		 * format which produces corrupted audio.
+		 * In case the dma driver does not implement the slave_caps the
+		 * default assumption is that it supports 1, 2 and 4 bytes
+		 * widths.
+		 */
+		pcm_for_each_format(i) {
+			int bits = snd_pcm_format_physical_width(i);
+
+			/*
+			 * Enable only samples with DMA supported physical
+			 * widths
+			 */
+			switch (bits) {
+			case 8:
+			case 16:
+			case 24:
+			case 32:
+			case 64:
+				if (addr_widths & (1 << (bits / 8)))
+					hw->formats |= pcm_format_to_bits(i);
+				break;
+			default:
+				/* Unsupported types */
+				break;
+			}
+		}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams);
+
+MODULE_LICENSE("GPL");
diff --git a/sound/core/pcm_drm_eld.c b/sound/core/pcm_drm_eld.c
new file mode 100644
index 0000000000..0707507197
--- /dev/null
+++ b/sound/core/pcm_drm_eld.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  PCM DRM helpers
+ */
+#include <linux/bitfield.h>
+#include <linux/export.h>
+#include <linux/hdmi.h>
+#include <drm/drm_edid.h>
+#include <sound/pcm.h>
+#include <sound/pcm_drm_eld.h>
+
+#define SAD0_CHANNELS_MASK	GENMASK(2, 0) /* max number of channels - 1 */
+#define SAD0_FORMAT_MASK	GENMASK(6, 3) /* audio format */
+
+#define SAD1_RATE_MASK		GENMASK(6, 0) /* bitfield of supported rates */
+#define SAD1_RATE_32000_MASK	BIT(0)
+#define SAD1_RATE_44100_MASK	BIT(1)
+#define SAD1_RATE_48000_MASK	BIT(2)
+#define SAD1_RATE_88200_MASK	BIT(3)
+#define SAD1_RATE_96000_MASK	BIT(4)
+#define SAD1_RATE_176400_MASK	BIT(5)
+#define SAD1_RATE_192000_MASK	BIT(6)
+
+static const unsigned int eld_rates[] = {
+	32000,
+	44100,
+	48000,
+	88200,
+	96000,
+	176400,
+	192000,
+};
+
+static unsigned int map_rate_families(const u8 *sad,
+				      unsigned int mask_32000,
+				      unsigned int mask_44100,
+				      unsigned int mask_48000)
+{
+	unsigned int rate_mask = 0;
+
+	if (sad[1] & SAD1_RATE_32000_MASK)
+		rate_mask |= mask_32000;
+	if (sad[1] & (SAD1_RATE_44100_MASK | SAD1_RATE_88200_MASK | SAD1_RATE_176400_MASK))
+		rate_mask |= mask_44100;
+	if (sad[1] & (SAD1_RATE_48000_MASK | SAD1_RATE_96000_MASK | SAD1_RATE_192000_MASK))
+		rate_mask |= mask_48000;
+	return rate_mask;
+}
+
+static unsigned int sad_rate_mask(const u8 *sad)
+{
+	switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {
+	case HDMI_AUDIO_CODING_TYPE_PCM:
+		return sad[1] & SAD1_RATE_MASK;
+	case HDMI_AUDIO_CODING_TYPE_AC3:
+	case HDMI_AUDIO_CODING_TYPE_DTS:
+		return map_rate_families(sad,
+					 SAD1_RATE_32000_MASK,
+					 SAD1_RATE_44100_MASK,
+					 SAD1_RATE_48000_MASK);
+	case HDMI_AUDIO_CODING_TYPE_EAC3:
+	case HDMI_AUDIO_CODING_TYPE_DTS_HD:
+	case HDMI_AUDIO_CODING_TYPE_MLP:
+		return map_rate_families(sad,
+					 0,
+					 SAD1_RATE_176400_MASK,
+					 SAD1_RATE_192000_MASK);
+	default:
+		/* TODO adjust for other compressed formats as well */
+		return sad[1] & SAD1_RATE_MASK;
+	}
+}
+
+static unsigned int sad_max_channels(const u8 *sad)
+{
+	switch (FIELD_GET(SAD0_FORMAT_MASK, sad[0])) {
+	case HDMI_AUDIO_CODING_TYPE_PCM:
+		return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);
+	case HDMI_AUDIO_CODING_TYPE_AC3:
+	case HDMI_AUDIO_CODING_TYPE_DTS:
+	case HDMI_AUDIO_CODING_TYPE_EAC3:
+		return 2;
+	case HDMI_AUDIO_CODING_TYPE_DTS_HD:
+	case HDMI_AUDIO_CODING_TYPE_MLP:
+		return 8;
+	default:
+		/* TODO adjust for other compressed formats as well */
+		return 1 + FIELD_GET(SAD0_CHANNELS_MASK, sad[0]);
+	}
+}
+
+static int eld_limit_rates(struct snd_pcm_hw_params *params,
+			   struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval *r = hw_param_interval(params, rule->var);
+	const struct snd_interval *c;
+	unsigned int rate_mask = 7, i;
+	const u8 *sad, *eld = rule->private;
+
+	sad = drm_eld_sad(eld);
+	if (sad) {
+		c = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+
+		for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) {
+			unsigned max_channels = sad_max_channels(sad);
+
+			/*
+			 * Exclude SADs which do not include the
+			 * requested number of channels.
+			 */
+			if (c->min <= max_channels)
+				rate_mask |= sad_rate_mask(sad);
+		}
+	}
+
+	return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates,
+				 rate_mask);
+}
+
+static int eld_limit_channels(struct snd_pcm_hw_params *params,
+			      struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval *c = hw_param_interval(params, rule->var);
+	const struct snd_interval *r;
+	struct snd_interval t = { .min = 1, .max = 2, .integer = 1, };
+	unsigned int i;
+	const u8 *sad, *eld = rule->private;
+
+	sad = drm_eld_sad(eld);
+	if (sad) {
+		unsigned int rate_mask = 0;
+
+		/* Convert the rate interval to a mask */
+		r = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
+		for (i = 0; i < ARRAY_SIZE(eld_rates); i++)
+			if (r->min <= eld_rates[i] && r->max >= eld_rates[i])
+				rate_mask |= BIT(i);
+
+		for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3)
+			if (rate_mask & sad_rate_mask(sad))
+				t.max = max(t.max, sad_max_channels(sad));
+	}
+
+	return snd_interval_refine(c, &t);
+}
+
+int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld)
+{
+	int ret;
+
+	ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+				  eld_limit_rates, eld,
+				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+				  eld_limit_channels, eld,
+				  SNDRV_PCM_HW_PARAM_RATE, -1);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);
diff --git a/sound/core/pcm_iec958.c b/sound/core/pcm_iec958.c
new file mode 100644
index 0000000000..7a1b816f67
--- /dev/null
+++ b/sound/core/pcm_iec958.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  PCM DRM helpers
+ */
+#include <linux/export.h>
+#include <linux/types.h>
+#include <sound/asoundef.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/pcm_iec958.h>
+
+/**
+ * snd_pcm_create_iec958_consumer_default - create default consumer format IEC958 channel status
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Create the consumer format channel status data in @cs of maximum size
+ * @len. When relevant, the configuration-dependant bits will be set as
+ * unspecified.
+ *
+ * Drivers should then call einter snd_pcm_fill_iec958_consumer() or
+ * snd_pcm_fill_iec958_consumer_hw_params() to replace these unspecified
+ * bits by their actual values.
+ *
+ * Drivers may wish to tweak the contents of the buffer after creation.
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_create_iec958_consumer_default(u8 *cs, size_t len)
+{
+	if (len < 4)
+		return -EINVAL;
+
+	memset(cs, 0, len);
+
+	cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
+	cs[1] = IEC958_AES1_CON_GENERAL;
+	cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
+	cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | IEC958_AES3_CON_FS_NOTID;
+
+	if (len > 4)
+		cs[4] = IEC958_AES4_CON_WORDLEN_NOTID;
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_create_iec958_consumer_default);
+
+static int fill_iec958_consumer(uint rate, uint sample_width,
+				u8 *cs, size_t len)
+{
+	if (len < 4)
+		return -EINVAL;
+
+	if ((cs[3] & IEC958_AES3_CON_FS) == IEC958_AES3_CON_FS_NOTID) {
+		unsigned int fs;
+
+		switch (rate) {
+			case 32000:
+				fs = IEC958_AES3_CON_FS_32000;
+				break;
+			case 44100:
+				fs = IEC958_AES3_CON_FS_44100;
+				break;
+			case 48000:
+				fs = IEC958_AES3_CON_FS_48000;
+				break;
+			case 88200:
+				fs = IEC958_AES3_CON_FS_88200;
+				break;
+			case 96000:
+				fs = IEC958_AES3_CON_FS_96000;
+				break;
+			case 176400:
+				fs = IEC958_AES3_CON_FS_176400;
+				break;
+			case 192000:
+				fs = IEC958_AES3_CON_FS_192000;
+				break;
+			default:
+				return -EINVAL;
+		}
+
+		cs[3] &= ~IEC958_AES3_CON_FS;
+		cs[3] |= fs;
+	}
+
+	if (len > 4 &&
+	    (cs[4] & IEC958_AES4_CON_WORDLEN) == IEC958_AES4_CON_WORDLEN_NOTID) {
+		unsigned int ws;
+
+		switch (sample_width) {
+		case 16:
+			ws = IEC958_AES4_CON_WORDLEN_20_16;
+			break;
+		case 18:
+			ws = IEC958_AES4_CON_WORDLEN_22_18;
+			break;
+		case 20:
+			ws = IEC958_AES4_CON_WORDLEN_20_16 |
+			     IEC958_AES4_CON_MAX_WORDLEN_24;
+			break;
+		case 24:
+		case 32: /* Assume 24-bit width for 32-bit samples. */
+			ws = IEC958_AES4_CON_WORDLEN_24_20 |
+			     IEC958_AES4_CON_MAX_WORDLEN_24;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+
+		cs[4] &= ~IEC958_AES4_CON_WORDLEN;
+		cs[4] |= ws;
+	}
+
+	return len;
+}
+
+/**
+ * snd_pcm_fill_iec958_consumer - Fill consumer format IEC958 channel status
+ * @runtime: pcm runtime structure with ->rate filled in
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Fill the unspecified bits in an IEC958 status bits array using the
+ * parameters of the PCM runtime @runtime.
+ *
+ * Drivers may wish to tweak the contents of the buffer after its been
+ * filled.
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_fill_iec958_consumer(struct snd_pcm_runtime *runtime,
+				 u8 *cs, size_t len)
+{
+	return fill_iec958_consumer(runtime->rate,
+				    snd_pcm_format_width(runtime->format),
+				    cs, len);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_fill_iec958_consumer);
+
+/**
+ * snd_pcm_fill_iec958_consumer_hw_params - Fill consumer format IEC958 channel status
+ * @params: the hw_params instance for extracting rate and sample format
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Fill the unspecified bits in an IEC958 status bits array using the
+ * parameters of the PCM hardware parameters @params.
+ *
+ * Drivers may wish to tweak the contents of the buffer after its been
+ * filled..
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_fill_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
+					   u8 *cs, size_t len)
+{
+	return fill_iec958_consumer(params_rate(params), params_width(params), cs, len);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_fill_iec958_consumer_hw_params);
+
+/**
+ * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
+ * @runtime: pcm runtime structure with ->rate filled in
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Create the consumer format channel status data in @cs of maximum size
+ * @len corresponding to the parameters of the PCM runtime @runtime.
+ *
+ * Drivers may wish to tweak the contents of the buffer after creation.
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
+	size_t len)
+{
+	int ret;
+
+	ret = snd_pcm_create_iec958_consumer_default(cs, len);
+	if (ret < 0)
+		return ret;
+
+	return snd_pcm_fill_iec958_consumer(runtime, cs, len);
+}
+EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
+
+/**
+ * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status
+ * @params: the hw_params instance for extracting rate and sample format
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Create the consumer format channel status data in @cs of maximum size
+ * @len corresponding to the parameters of the PCM runtime @runtime.
+ *
+ * Drivers may wish to tweak the contents of the buffer after creation.
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
+					     u8 *cs, size_t len)
+{
+	int ret;
+
+	ret = snd_pcm_create_iec958_consumer_default(cs, len);
+	if (ret < 0)
+		return ret;
+
+	return fill_iec958_consumer(params_rate(params), params_width(params), cs, len);
+}
+EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
new file mode 100644
index 0000000000..a11cd7d629
--- /dev/null
+++ b/sound/core/pcm_lib.c
@@ -0,0 +1,2567 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *                   Abramo Bagnara <abramo@alsa-project.org>
+ */
+
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/time.h>
+#include <linux/math64.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/timer.h>
+
+#include "pcm_local.h"
+
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+#define CREATE_TRACE_POINTS
+#include "pcm_trace.h"
+#else
+#define trace_hwptr(substream, pos, in_interrupt)
+#define trace_xrun(substream)
+#define trace_hw_ptr_error(substream, reason)
+#define trace_applptr(substream, prev, curr)
+#endif
+
+static int fill_silence_frames(struct snd_pcm_substream *substream,
+			       snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
+
+
+static inline void update_silence_vars(struct snd_pcm_runtime *runtime,
+				       snd_pcm_uframes_t ptr,
+				       snd_pcm_uframes_t new_ptr)
+{
+	snd_pcm_sframes_t delta;
+
+	delta = new_ptr - ptr;
+	if (delta == 0)
+		return;
+	if (delta < 0)
+		delta += runtime->boundary;
+	if ((snd_pcm_uframes_t)delta < runtime->silence_filled)
+		runtime->silence_filled -= delta;
+	else
+		runtime->silence_filled = 0;
+	runtime->silence_start = new_ptr;
+}
+
+/*
+ * fill ring buffer with silence
+ * runtime->silence_start: starting pointer to silence area
+ * runtime->silence_filled: size filled with silence
+ * runtime->silence_threshold: threshold from application
+ * runtime->silence_size: maximal size from application
+ *
+ * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
+ */
+void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t frames, ofs, transfer;
+	int err;
+
+	if (runtime->silence_size < runtime->boundary) {
+		snd_pcm_sframes_t noise_dist;
+		snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
+		update_silence_vars(runtime, runtime->silence_start, appl_ptr);
+		/* initialization outside pointer updates */
+		if (new_hw_ptr == ULONG_MAX)
+			new_hw_ptr = runtime->status->hw_ptr;
+		/* get hw_avail with the boundary crossing */
+		noise_dist = appl_ptr - new_hw_ptr;
+		if (noise_dist < 0)
+			noise_dist += runtime->boundary;
+		/* total noise distance */
+		noise_dist += runtime->silence_filled;
+		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
+			return;
+		frames = runtime->silence_threshold - noise_dist;
+		if (frames > runtime->silence_size)
+			frames = runtime->silence_size;
+	} else {
+		/*
+		 * This filling mode aims at free-running mode (used for example by dmix),
+		 * which doesn't update the application pointer.
+		 */
+		snd_pcm_uframes_t hw_ptr = runtime->status->hw_ptr;
+		if (new_hw_ptr == ULONG_MAX) {
+			/*
+			 * Initialization, fill the whole unused buffer with silence.
+			 *
+			 * Usually, this is entered while stopped, before data is queued,
+			 * so both pointers are expected to be zero.
+			 */
+			snd_pcm_sframes_t avail = runtime->control->appl_ptr - hw_ptr;
+			if (avail < 0)
+				avail += runtime->boundary;
+			/*
+			 * In free-running mode, appl_ptr will be zero even while running,
+			 * so we end up with a huge number. There is no useful way to
+			 * handle this, so we just clear the whole buffer.
+			 */
+			runtime->silence_filled = avail > runtime->buffer_size ? 0 : avail;
+			runtime->silence_start = hw_ptr;
+		} else {
+			/* Silence the just played area immediately */
+			update_silence_vars(runtime, hw_ptr, new_hw_ptr);
+		}
+		/*
+		 * In this mode, silence_filled actually includes the valid
+		 * sample data from the user.
+		 */
+		frames = runtime->buffer_size - runtime->silence_filled;
+	}
+	if (snd_BUG_ON(frames > runtime->buffer_size))
+		return;
+	if (frames == 0)
+		return;
+	ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size;
+	do {
+		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
+		err = fill_silence_frames(substream, ofs, transfer);
+		snd_BUG_ON(err < 0);
+		runtime->silence_filled += transfer;
+		frames -= transfer;
+		ofs = 0;
+	} while (frames > 0);
+	snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+}
+
+#ifdef CONFIG_SND_DEBUG
+void snd_pcm_debug_name(struct snd_pcm_substream *substream,
+			   char *name, size_t len)
+{
+	snprintf(name, len, "pcmC%dD%d%c:%d",
+		 substream->pcm->card->number,
+		 substream->pcm->device,
+		 substream->stream ? 'c' : 'p',
+		 substream->number);
+}
+EXPORT_SYMBOL(snd_pcm_debug_name);
+#endif
+
+#define XRUN_DEBUG_BASIC	(1<<0)
+#define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
+#define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
+
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+
+#define xrun_debug(substream, mask) \
+			((substream)->pstr->xrun_debug & (mask))
+#else
+#define xrun_debug(substream, mask)	0
+#endif
+
+#define dump_stack_on_xrun(substream) do {			\
+		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
+			dump_stack();				\
+	} while (0)
+
+/* call with stream lock held */
+void __snd_pcm_xrun(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	trace_xrun(substream);
+	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
+		struct timespec64 tstamp;
+
+		snd_pcm_gettime(runtime, &tstamp);
+		runtime->status->tstamp.tv_sec = tstamp.tv_sec;
+		runtime->status->tstamp.tv_nsec = tstamp.tv_nsec;
+	}
+	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
+		char name[16];
+		snd_pcm_debug_name(substream, name, sizeof(name));
+		pcm_warn(substream->pcm, "XRUN: %s\n", name);
+		dump_stack_on_xrun(substream);
+	}
+}
+
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+#define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)	\
+	do {								\
+		trace_hw_ptr_error(substream, reason);	\
+		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
+			pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
+					   (in_interrupt) ? 'Q' : 'P', ##args);	\
+			dump_stack_on_xrun(substream);			\
+		}							\
+	} while (0)
+
+#else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
+
+#define hw_ptr_error(substream, fmt, args...) do { } while (0)
+
+#endif
+
+int snd_pcm_update_state(struct snd_pcm_substream *substream,
+			 struct snd_pcm_runtime *runtime)
+{
+	snd_pcm_uframes_t avail;
+
+	avail = snd_pcm_avail(substream);
+	if (avail > runtime->avail_max)
+		runtime->avail_max = avail;
+	if (runtime->state == SNDRV_PCM_STATE_DRAINING) {
+		if (avail >= runtime->buffer_size) {
+			snd_pcm_drain_done(substream);
+			return -EPIPE;
+		}
+	} else {
+		if (avail >= runtime->stop_threshold) {
+			__snd_pcm_xrun(substream);
+			return -EPIPE;
+		}
+	}
+	if (runtime->twake) {
+		if (avail >= runtime->twake)
+			wake_up(&runtime->tsleep);
+	} else if (avail >= runtime->control->avail_min)
+		wake_up(&runtime->sleep);
+	return 0;
+}
+
+static void update_audio_tstamp(struct snd_pcm_substream *substream,
+				struct timespec64 *curr_tstamp,
+				struct timespec64 *audio_tstamp)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	u64 audio_frames, audio_nsecs;
+	struct timespec64 driver_tstamp;
+
+	if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
+		return;
+
+	if (!(substream->ops->get_time_info) ||
+		(runtime->audio_tstamp_report.actual_type ==
+			SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
+
+		/*
+		 * provide audio timestamp derived from pointer position
+		 * add delay only if requested
+		 */
+
+		audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
+
+		if (runtime->audio_tstamp_config.report_delay) {
+			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+				audio_frames -=  runtime->delay;
+			else
+				audio_frames +=  runtime->delay;
+		}
+		audio_nsecs = div_u64(audio_frames * 1000000000LL,
+				runtime->rate);
+		*audio_tstamp = ns_to_timespec64(audio_nsecs);
+	}
+
+	if (runtime->status->audio_tstamp.tv_sec != audio_tstamp->tv_sec ||
+	    runtime->status->audio_tstamp.tv_nsec != audio_tstamp->tv_nsec) {
+		runtime->status->audio_tstamp.tv_sec = audio_tstamp->tv_sec;
+		runtime->status->audio_tstamp.tv_nsec = audio_tstamp->tv_nsec;
+		runtime->status->tstamp.tv_sec = curr_tstamp->tv_sec;
+		runtime->status->tstamp.tv_nsec = curr_tstamp->tv_nsec;
+	}
+
+
+	/*
+	 * re-take a driver timestamp to let apps detect if the reference tstamp
+	 * read by low-level hardware was provided with a delay
+	 */
+	snd_pcm_gettime(substream->runtime, &driver_tstamp);
+	runtime->driver_tstamp = driver_tstamp;
+}
+
+static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
+				  unsigned int in_interrupt)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t pos;
+	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
+	snd_pcm_sframes_t hdelta, delta;
+	unsigned long jdelta;
+	unsigned long curr_jiffies;
+	struct timespec64 curr_tstamp;
+	struct timespec64 audio_tstamp;
+	int crossed_boundary = 0;
+
+	old_hw_ptr = runtime->status->hw_ptr;
+
+	/*
+	 * group pointer, time and jiffies reads to allow for more
+	 * accurate correlations/corrections.
+	 * The values are stored at the end of this routine after
+	 * corrections for hw_ptr position
+	 */
+	pos = substream->ops->pointer(substream);
+	curr_jiffies = jiffies;
+	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
+		if ((substream->ops->get_time_info) &&
+			(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
+			substream->ops->get_time_info(substream, &curr_tstamp,
+						&audio_tstamp,
+						&runtime->audio_tstamp_config,
+						&runtime->audio_tstamp_report);
+
+			/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
+			if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
+				snd_pcm_gettime(runtime, &curr_tstamp);
+		} else
+			snd_pcm_gettime(runtime, &curr_tstamp);
+	}
+
+	if (pos == SNDRV_PCM_POS_XRUN) {
+		__snd_pcm_xrun(substream);
+		return -EPIPE;
+	}
+	if (pos >= runtime->buffer_size) {
+		if (printk_ratelimit()) {
+			char name[16];
+			snd_pcm_debug_name(substream, name, sizeof(name));
+			pcm_err(substream->pcm,
+				"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
+				name, pos, runtime->buffer_size,
+				runtime->period_size);
+		}
+		pos = 0;
+	}
+	pos -= pos % runtime->min_align;
+	trace_hwptr(substream, pos, in_interrupt);
+	hw_base = runtime->hw_ptr_base;
+	new_hw_ptr = hw_base + pos;
+	if (in_interrupt) {
+		/* we know that one period was processed */
+		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
+		delta = runtime->hw_ptr_interrupt + runtime->period_size;
+		if (delta > new_hw_ptr) {
+			/* check for double acknowledged interrupts */
+			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
+			if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
+				hw_base += runtime->buffer_size;
+				if (hw_base >= runtime->boundary) {
+					hw_base = 0;
+					crossed_boundary++;
+				}
+				new_hw_ptr = hw_base + pos;
+				goto __delta;
+			}
+		}
+	}
+	/* new_hw_ptr might be lower than old_hw_ptr in case when */
+	/* pointer crosses the end of the ring buffer */
+	if (new_hw_ptr < old_hw_ptr) {
+		hw_base += runtime->buffer_size;
+		if (hw_base >= runtime->boundary) {
+			hw_base = 0;
+			crossed_boundary++;
+		}
+		new_hw_ptr = hw_base + pos;
+	}
+      __delta:
+	delta = new_hw_ptr - old_hw_ptr;
+	if (delta < 0)
+		delta += runtime->boundary;
+
+	if (runtime->no_period_wakeup) {
+		snd_pcm_sframes_t xrun_threshold;
+		/*
+		 * Without regular period interrupts, we have to check
+		 * the elapsed time to detect xruns.
+		 */
+		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
+		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
+			goto no_delta_check;
+		hdelta = jdelta - delta * HZ / runtime->rate;
+		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
+		while (hdelta > xrun_threshold) {
+			delta += runtime->buffer_size;
+			hw_base += runtime->buffer_size;
+			if (hw_base >= runtime->boundary) {
+				hw_base = 0;
+				crossed_boundary++;
+			}
+			new_hw_ptr = hw_base + pos;
+			hdelta -= runtime->hw_ptr_buffer_jiffies;
+		}
+		goto no_delta_check;
+	}
+
+	/* something must be really wrong */
+	if (delta >= runtime->buffer_size + runtime->period_size) {
+		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
+			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
+			     substream->stream, (long)pos,
+			     (long)new_hw_ptr, (long)old_hw_ptr);
+		return 0;
+	}
+
+	/* Do jiffies check only in xrun_debug mode */
+	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
+		goto no_jiffies_check;
+
+	/* Skip the jiffies check for hardwares with BATCH flag.
+	 * Such hardware usually just increases the position at each IRQ,
+	 * thus it can't give any strange position.
+	 */
+	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
+		goto no_jiffies_check;
+	hdelta = delta;
+	if (hdelta < runtime->delay)
+		goto no_jiffies_check;
+	hdelta -= runtime->delay;
+	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
+	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
+		delta = jdelta /
+			(((runtime->period_size * HZ) / runtime->rate)
+								+ HZ/100);
+		/* move new_hw_ptr according jiffies not pos variable */
+		new_hw_ptr = old_hw_ptr;
+		hw_base = delta;
+		/* use loop to avoid checks for delta overflows */
+		/* the delta value is small or zero in most cases */
+		while (delta > 0) {
+			new_hw_ptr += runtime->period_size;
+			if (new_hw_ptr >= runtime->boundary) {
+				new_hw_ptr -= runtime->boundary;
+				crossed_boundary--;
+			}
+			delta--;
+		}
+		/* align hw_base to buffer_size */
+		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
+			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
+			     (long)pos, (long)hdelta,
+			     (long)runtime->period_size, jdelta,
+			     ((hdelta * HZ) / runtime->rate), hw_base,
+			     (unsigned long)old_hw_ptr,
+			     (unsigned long)new_hw_ptr);
+		/* reset values to proper state */
+		delta = 0;
+		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
+	}
+ no_jiffies_check:
+	if (delta > runtime->period_size + runtime->period_size / 2) {
+		hw_ptr_error(substream, in_interrupt,
+			     "Lost interrupts?",
+			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
+			     substream->stream, (long)delta,
+			     (long)new_hw_ptr,
+			     (long)old_hw_ptr);
+	}
+
+ no_delta_check:
+	if (runtime->status->hw_ptr == new_hw_ptr) {
+		runtime->hw_ptr_jiffies = curr_jiffies;
+		update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
+		return 0;
+	}
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+	    runtime->silence_size > 0)
+		snd_pcm_playback_silence(substream, new_hw_ptr);
+
+	if (in_interrupt) {
+		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
+		if (delta < 0)
+			delta += runtime->boundary;
+		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
+		runtime->hw_ptr_interrupt += delta;
+		if (runtime->hw_ptr_interrupt >= runtime->boundary)
+			runtime->hw_ptr_interrupt -= runtime->boundary;
+	}
+	runtime->hw_ptr_base = hw_base;
+	runtime->status->hw_ptr = new_hw_ptr;
+	runtime->hw_ptr_jiffies = curr_jiffies;
+	if (crossed_boundary) {
+		snd_BUG_ON(crossed_boundary != 1);
+		runtime->hw_ptr_wrap += runtime->boundary;
+	}
+
+	update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
+
+	return snd_pcm_update_state(substream, runtime);
+}
+
+/* CAUTION: call it with irq disabled */
+int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_update_hw_ptr0(substream, 0);
+}
+
+/**
+ * snd_pcm_set_ops - set the PCM operators
+ * @pcm: the pcm instance
+ * @direction: stream direction, SNDRV_PCM_STREAM_XXX
+ * @ops: the operator table
+ *
+ * Sets the given PCM operators to the pcm instance.
+ */
+void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
+		     const struct snd_pcm_ops *ops)
+{
+	struct snd_pcm_str *stream = &pcm->streams[direction];
+	struct snd_pcm_substream *substream;
+	
+	for (substream = stream->substream; substream != NULL; substream = substream->next)
+		substream->ops = ops;
+}
+EXPORT_SYMBOL(snd_pcm_set_ops);
+
+/**
+ * snd_pcm_set_sync - set the PCM sync id
+ * @substream: the pcm substream
+ *
+ * Sets the PCM sync identifier for the card.
+ */
+void snd_pcm_set_sync(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	
+	runtime->sync.id32[0] = substream->pcm->card->number;
+	runtime->sync.id32[1] = -1;
+	runtime->sync.id32[2] = -1;
+	runtime->sync.id32[3] = -1;
+}
+EXPORT_SYMBOL(snd_pcm_set_sync);
+
+/*
+ *  Standard ioctl routine
+ */
+
+static inline unsigned int div32(unsigned int a, unsigned int b, 
+				 unsigned int *r)
+{
+	if (b == 0) {
+		*r = 0;
+		return UINT_MAX;
+	}
+	*r = a % b;
+	return a / b;
+}
+
+static inline unsigned int div_down(unsigned int a, unsigned int b)
+{
+	if (b == 0)
+		return UINT_MAX;
+	return a / b;
+}
+
+static inline unsigned int div_up(unsigned int a, unsigned int b)
+{
+	unsigned int r;
+	unsigned int q;
+	if (b == 0)
+		return UINT_MAX;
+	q = div32(a, b, &r);
+	if (r)
+		++q;
+	return q;
+}
+
+static inline unsigned int mul(unsigned int a, unsigned int b)
+{
+	if (a == 0)
+		return 0;
+	if (div_down(UINT_MAX, a) < b)
+		return UINT_MAX;
+	return a * b;
+}
+
+static inline unsigned int muldiv32(unsigned int a, unsigned int b,
+				    unsigned int c, unsigned int *r)
+{
+	u_int64_t n = (u_int64_t) a * b;
+	if (c == 0) {
+		*r = 0;
+		return UINT_MAX;
+	}
+	n = div_u64_rem(n, c, r);
+	if (n >= UINT_MAX) {
+		*r = 0;
+		return UINT_MAX;
+	}
+	return n;
+}
+
+/**
+ * snd_interval_refine - refine the interval value of configurator
+ * @i: the interval value to refine
+ * @v: the interval value to refer to
+ *
+ * Refines the interval value with the reference value.
+ * The interval is changed to the range satisfying both intervals.
+ * The interval status (min, max, integer, etc.) are evaluated.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
+{
+	int changed = 0;
+	if (snd_BUG_ON(snd_interval_empty(i)))
+		return -EINVAL;
+	if (i->min < v->min) {
+		i->min = v->min;
+		i->openmin = v->openmin;
+		changed = 1;
+	} else if (i->min == v->min && !i->openmin && v->openmin) {
+		i->openmin = 1;
+		changed = 1;
+	}
+	if (i->max > v->max) {
+		i->max = v->max;
+		i->openmax = v->openmax;
+		changed = 1;
+	} else if (i->max == v->max && !i->openmax && v->openmax) {
+		i->openmax = 1;
+		changed = 1;
+	}
+	if (!i->integer && v->integer) {
+		i->integer = 1;
+		changed = 1;
+	}
+	if (i->integer) {
+		if (i->openmin) {
+			i->min++;
+			i->openmin = 0;
+		}
+		if (i->openmax) {
+			i->max--;
+			i->openmax = 0;
+		}
+	} else if (!i->openmin && !i->openmax && i->min == i->max)
+		i->integer = 1;
+	if (snd_interval_checkempty(i)) {
+		snd_interval_none(i);
+		return -EINVAL;
+	}
+	return changed;
+}
+EXPORT_SYMBOL(snd_interval_refine);
+
+static int snd_interval_refine_first(struct snd_interval *i)
+{
+	const unsigned int last_max = i->max;
+
+	if (snd_BUG_ON(snd_interval_empty(i)))
+		return -EINVAL;
+	if (snd_interval_single(i))
+		return 0;
+	i->max = i->min;
+	if (i->openmin)
+		i->max++;
+	/* only exclude max value if also excluded before refine */
+	i->openmax = (i->openmax && i->max >= last_max);
+	return 1;
+}
+
+static int snd_interval_refine_last(struct snd_interval *i)
+{
+	const unsigned int last_min = i->min;
+
+	if (snd_BUG_ON(snd_interval_empty(i)))
+		return -EINVAL;
+	if (snd_interval_single(i))
+		return 0;
+	i->min = i->max;
+	if (i->openmax)
+		i->min--;
+	/* only exclude min value if also excluded before refine */
+	i->openmin = (i->openmin && i->min <= last_min);
+	return 1;
+}
+
+void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
+{
+	if (a->empty || b->empty) {
+		snd_interval_none(c);
+		return;
+	}
+	c->empty = 0;
+	c->min = mul(a->min, b->min);
+	c->openmin = (a->openmin || b->openmin);
+	c->max = mul(a->max,  b->max);
+	c->openmax = (a->openmax || b->openmax);
+	c->integer = (a->integer && b->integer);
+}
+
+/**
+ * snd_interval_div - refine the interval value with division
+ * @a: dividend
+ * @b: divisor
+ * @c: quotient
+ *
+ * c = a / b
+ *
+ * Returns non-zero if the value is changed, zero if not changed.
+ */
+void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
+{
+	unsigned int r;
+	if (a->empty || b->empty) {
+		snd_interval_none(c);
+		return;
+	}
+	c->empty = 0;
+	c->min = div32(a->min, b->max, &r);
+	c->openmin = (r || a->openmin || b->openmax);
+	if (b->min > 0) {
+		c->max = div32(a->max, b->min, &r);
+		if (r) {
+			c->max++;
+			c->openmax = 1;
+		} else
+			c->openmax = (a->openmax || b->openmin);
+	} else {
+		c->max = UINT_MAX;
+		c->openmax = 0;
+	}
+	c->integer = 0;
+}
+
+/**
+ * snd_interval_muldivk - refine the interval value
+ * @a: dividend 1
+ * @b: dividend 2
+ * @k: divisor (as integer)
+ * @c: result
+  *
+ * c = a * b / k
+ *
+ * Returns non-zero if the value is changed, zero if not changed.
+ */
+void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
+		      unsigned int k, struct snd_interval *c)
+{
+	unsigned int r;
+	if (a->empty || b->empty) {
+		snd_interval_none(c);
+		return;
+	}
+	c->empty = 0;
+	c->min = muldiv32(a->min, b->min, k, &r);
+	c->openmin = (r || a->openmin || b->openmin);
+	c->max = muldiv32(a->max, b->max, k, &r);
+	if (r) {
+		c->max++;
+		c->openmax = 1;
+	} else
+		c->openmax = (a->openmax || b->openmax);
+	c->integer = 0;
+}
+
+/**
+ * snd_interval_mulkdiv - refine the interval value
+ * @a: dividend 1
+ * @k: dividend 2 (as integer)
+ * @b: divisor
+ * @c: result
+ *
+ * c = a * k / b
+ *
+ * Returns non-zero if the value is changed, zero if not changed.
+ */
+void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
+		      const struct snd_interval *b, struct snd_interval *c)
+{
+	unsigned int r;
+	if (a->empty || b->empty) {
+		snd_interval_none(c);
+		return;
+	}
+	c->empty = 0;
+	c->min = muldiv32(a->min, k, b->max, &r);
+	c->openmin = (r || a->openmin || b->openmax);
+	if (b->min > 0) {
+		c->max = muldiv32(a->max, k, b->min, &r);
+		if (r) {
+			c->max++;
+			c->openmax = 1;
+		} else
+			c->openmax = (a->openmax || b->openmin);
+	} else {
+		c->max = UINT_MAX;
+		c->openmax = 0;
+	}
+	c->integer = 0;
+}
+
+/* ---- */
+
+
+/**
+ * snd_interval_ratnum - refine the interval value
+ * @i: interval to refine
+ * @rats_count: number of ratnum_t 
+ * @rats: ratnum_t array
+ * @nump: pointer to store the resultant numerator
+ * @denp: pointer to store the resultant denominator
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+int snd_interval_ratnum(struct snd_interval *i,
+			unsigned int rats_count, const struct snd_ratnum *rats,
+			unsigned int *nump, unsigned int *denp)
+{
+	unsigned int best_num, best_den;
+	int best_diff;
+	unsigned int k;
+	struct snd_interval t;
+	int err;
+	unsigned int result_num, result_den;
+	int result_diff;
+
+	best_num = best_den = best_diff = 0;
+	for (k = 0; k < rats_count; ++k) {
+		unsigned int num = rats[k].num;
+		unsigned int den;
+		unsigned int q = i->min;
+		int diff;
+		if (q == 0)
+			q = 1;
+		den = div_up(num, q);
+		if (den < rats[k].den_min)
+			continue;
+		if (den > rats[k].den_max)
+			den = rats[k].den_max;
+		else {
+			unsigned int r;
+			r = (den - rats[k].den_min) % rats[k].den_step;
+			if (r != 0)
+				den -= r;
+		}
+		diff = num - q * den;
+		if (diff < 0)
+			diff = -diff;
+		if (best_num == 0 ||
+		    diff * best_den < best_diff * den) {
+			best_diff = diff;
+			best_den = den;
+			best_num = num;
+		}
+	}
+	if (best_den == 0) {
+		i->empty = 1;
+		return -EINVAL;
+	}
+	t.min = div_down(best_num, best_den);
+	t.openmin = !!(best_num % best_den);
+	
+	result_num = best_num;
+	result_diff = best_diff;
+	result_den = best_den;
+	best_num = best_den = best_diff = 0;
+	for (k = 0; k < rats_count; ++k) {
+		unsigned int num = rats[k].num;
+		unsigned int den;
+		unsigned int q = i->max;
+		int diff;
+		if (q == 0) {
+			i->empty = 1;
+			return -EINVAL;
+		}
+		den = div_down(num, q);
+		if (den > rats[k].den_max)
+			continue;
+		if (den < rats[k].den_min)
+			den = rats[k].den_min;
+		else {
+			unsigned int r;
+			r = (den - rats[k].den_min) % rats[k].den_step;
+			if (r != 0)
+				den += rats[k].den_step - r;
+		}
+		diff = q * den - num;
+		if (diff < 0)
+			diff = -diff;
+		if (best_num == 0 ||
+		    diff * best_den < best_diff * den) {
+			best_diff = diff;
+			best_den = den;
+			best_num = num;
+		}
+	}
+	if (best_den == 0) {
+		i->empty = 1;
+		return -EINVAL;
+	}
+	t.max = div_up(best_num, best_den);
+	t.openmax = !!(best_num % best_den);
+	t.integer = 0;
+	err = snd_interval_refine(i, &t);
+	if (err < 0)
+		return err;
+
+	if (snd_interval_single(i)) {
+		if (best_diff * result_den < result_diff * best_den) {
+			result_num = best_num;
+			result_den = best_den;
+		}
+		if (nump)
+			*nump = result_num;
+		if (denp)
+			*denp = result_den;
+	}
+	return err;
+}
+EXPORT_SYMBOL(snd_interval_ratnum);
+
+/**
+ * snd_interval_ratden - refine the interval value
+ * @i: interval to refine
+ * @rats_count: number of struct ratden
+ * @rats: struct ratden array
+ * @nump: pointer to store the resultant numerator
+ * @denp: pointer to store the resultant denominator
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+static int snd_interval_ratden(struct snd_interval *i,
+			       unsigned int rats_count,
+			       const struct snd_ratden *rats,
+			       unsigned int *nump, unsigned int *denp)
+{
+	unsigned int best_num, best_diff, best_den;
+	unsigned int k;
+	struct snd_interval t;
+	int err;
+
+	best_num = best_den = best_diff = 0;
+	for (k = 0; k < rats_count; ++k) {
+		unsigned int num;
+		unsigned int den = rats[k].den;
+		unsigned int q = i->min;
+		int diff;
+		num = mul(q, den);
+		if (num > rats[k].num_max)
+			continue;
+		if (num < rats[k].num_min)
+			num = rats[k].num_max;
+		else {
+			unsigned int r;
+			r = (num - rats[k].num_min) % rats[k].num_step;
+			if (r != 0)
+				num += rats[k].num_step - r;
+		}
+		diff = num - q * den;
+		if (best_num == 0 ||
+		    diff * best_den < best_diff * den) {
+			best_diff = diff;
+			best_den = den;
+			best_num = num;
+		}
+	}
+	if (best_den == 0) {
+		i->empty = 1;
+		return -EINVAL;
+	}
+	t.min = div_down(best_num, best_den);
+	t.openmin = !!(best_num % best_den);
+	
+	best_num = best_den = best_diff = 0;
+	for (k = 0; k < rats_count; ++k) {
+		unsigned int num;
+		unsigned int den = rats[k].den;
+		unsigned int q = i->max;
+		int diff;
+		num = mul(q, den);
+		if (num < rats[k].num_min)
+			continue;
+		if (num > rats[k].num_max)
+			num = rats[k].num_max;
+		else {
+			unsigned int r;
+			r = (num - rats[k].num_min) % rats[k].num_step;
+			if (r != 0)
+				num -= r;
+		}
+		diff = q * den - num;
+		if (best_num == 0 ||
+		    diff * best_den < best_diff * den) {
+			best_diff = diff;
+			best_den = den;
+			best_num = num;
+		}
+	}
+	if (best_den == 0) {
+		i->empty = 1;
+		return -EINVAL;
+	}
+	t.max = div_up(best_num, best_den);
+	t.openmax = !!(best_num % best_den);
+	t.integer = 0;
+	err = snd_interval_refine(i, &t);
+	if (err < 0)
+		return err;
+
+	if (snd_interval_single(i)) {
+		if (nump)
+			*nump = best_num;
+		if (denp)
+			*denp = best_den;
+	}
+	return err;
+}
+
+/**
+ * snd_interval_list - refine the interval value from the list
+ * @i: the interval value to refine
+ * @count: the number of elements in the list
+ * @list: the value list
+ * @mask: the bit-mask to evaluate
+ *
+ * Refines the interval value from the list.
+ * When mask is non-zero, only the elements corresponding to bit 1 are
+ * evaluated.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+int snd_interval_list(struct snd_interval *i, unsigned int count,
+		      const unsigned int *list, unsigned int mask)
+{
+        unsigned int k;
+	struct snd_interval list_range;
+
+	if (!count) {
+		i->empty = 1;
+		return -EINVAL;
+	}
+	snd_interval_any(&list_range);
+	list_range.min = UINT_MAX;
+	list_range.max = 0;
+        for (k = 0; k < count; k++) {
+		if (mask && !(mask & (1 << k)))
+			continue;
+		if (!snd_interval_test(i, list[k]))
+			continue;
+		list_range.min = min(list_range.min, list[k]);
+		list_range.max = max(list_range.max, list[k]);
+        }
+	return snd_interval_refine(i, &list_range);
+}
+EXPORT_SYMBOL(snd_interval_list);
+
+/**
+ * snd_interval_ranges - refine the interval value from the list of ranges
+ * @i: the interval value to refine
+ * @count: the number of elements in the list of ranges
+ * @ranges: the ranges list
+ * @mask: the bit-mask to evaluate
+ *
+ * Refines the interval value from the list of ranges.
+ * When mask is non-zero, only the elements corresponding to bit 1 are
+ * evaluated.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+int snd_interval_ranges(struct snd_interval *i, unsigned int count,
+			const struct snd_interval *ranges, unsigned int mask)
+{
+	unsigned int k;
+	struct snd_interval range_union;
+	struct snd_interval range;
+
+	if (!count) {
+		snd_interval_none(i);
+		return -EINVAL;
+	}
+	snd_interval_any(&range_union);
+	range_union.min = UINT_MAX;
+	range_union.max = 0;
+	for (k = 0; k < count; k++) {
+		if (mask && !(mask & (1 << k)))
+			continue;
+		snd_interval_copy(&range, &ranges[k]);
+		if (snd_interval_refine(&range, i) < 0)
+			continue;
+		if (snd_interval_empty(&range))
+			continue;
+
+		if (range.min < range_union.min) {
+			range_union.min = range.min;
+			range_union.openmin = 1;
+		}
+		if (range.min == range_union.min && !range.openmin)
+			range_union.openmin = 0;
+		if (range.max > range_union.max) {
+			range_union.max = range.max;
+			range_union.openmax = 1;
+		}
+		if (range.max == range_union.max && !range.openmax)
+			range_union.openmax = 0;
+	}
+	return snd_interval_refine(i, &range_union);
+}
+EXPORT_SYMBOL(snd_interval_ranges);
+
+static int snd_interval_step(struct snd_interval *i, unsigned int step)
+{
+	unsigned int n;
+	int changed = 0;
+	n = i->min % step;
+	if (n != 0 || i->openmin) {
+		i->min += step - n;
+		i->openmin = 0;
+		changed = 1;
+	}
+	n = i->max % step;
+	if (n != 0 || i->openmax) {
+		i->max -= n;
+		i->openmax = 0;
+		changed = 1;
+	}
+	if (snd_interval_checkempty(i)) {
+		i->empty = 1;
+		return -EINVAL;
+	}
+	return changed;
+}
+
+/* Info constraints helpers */
+
+/**
+ * snd_pcm_hw_rule_add - add the hw-constraint rule
+ * @runtime: the pcm runtime instance
+ * @cond: condition bits
+ * @var: the variable to evaluate
+ * @func: the evaluation function
+ * @private: the private data pointer passed to function
+ * @dep: the dependent variables
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
+			int var,
+			snd_pcm_hw_rule_func_t func, void *private,
+			int dep, ...)
+{
+	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
+	struct snd_pcm_hw_rule *c;
+	unsigned int k;
+	va_list args;
+	va_start(args, dep);
+	if (constrs->rules_num >= constrs->rules_all) {
+		struct snd_pcm_hw_rule *new;
+		unsigned int new_rules = constrs->rules_all + 16;
+		new = krealloc_array(constrs->rules, new_rules,
+				     sizeof(*c), GFP_KERNEL);
+		if (!new) {
+			va_end(args);
+			return -ENOMEM;
+		}
+		constrs->rules = new;
+		constrs->rules_all = new_rules;
+	}
+	c = &constrs->rules[constrs->rules_num];
+	c->cond = cond;
+	c->func = func;
+	c->var = var;
+	c->private = private;
+	k = 0;
+	while (1) {
+		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
+			va_end(args);
+			return -EINVAL;
+		}
+		c->deps[k++] = dep;
+		if (dep < 0)
+			break;
+		dep = va_arg(args, int);
+	}
+	constrs->rules_num++;
+	va_end(args);
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_hw_rule_add);
+
+/**
+ * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
+ * @runtime: PCM runtime instance
+ * @var: hw_params variable to apply the mask
+ * @mask: the bitmap mask
+ *
+ * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
+			       u_int32_t mask)
+{
+	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
+	struct snd_mask *maskp = constrs_mask(constrs, var);
+	*maskp->bits &= mask;
+	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
+	if (*maskp->bits == 0)
+		return -EINVAL;
+	return 0;
+}
+
+/**
+ * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
+ * @runtime: PCM runtime instance
+ * @var: hw_params variable to apply the mask
+ * @mask: the 64bit bitmap mask
+ *
+ * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
+				 u_int64_t mask)
+{
+	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
+	struct snd_mask *maskp = constrs_mask(constrs, var);
+	maskp->bits[0] &= (u_int32_t)mask;
+	maskp->bits[1] &= (u_int32_t)(mask >> 32);
+	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
+	if (! maskp->bits[0] && ! maskp->bits[1])
+		return -EINVAL;
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
+
+/**
+ * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
+ * @runtime: PCM runtime instance
+ * @var: hw_params variable to apply the integer constraint
+ *
+ * Apply the constraint of integer to an interval parameter.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
+{
+	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
+	return snd_interval_setinteger(constrs_interval(constrs, var));
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
+
+/**
+ * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
+ * @runtime: PCM runtime instance
+ * @var: hw_params variable to apply the range
+ * @min: the minimal value
+ * @max: the maximal value
+ * 
+ * Apply the min/max range constraint to an interval parameter.
+ *
+ * Return: Positive if the value is changed, zero if it's not changed, or a
+ * negative error code.
+ */
+int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
+				 unsigned int min, unsigned int max)
+{
+	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
+	struct snd_interval t;
+	t.min = min;
+	t.max = max;
+	t.openmin = t.openmax = 0;
+	t.integer = 0;
+	return snd_interval_refine(constrs_interval(constrs, var), &t);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
+
+static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
+				struct snd_pcm_hw_rule *rule)
+{
+	struct snd_pcm_hw_constraint_list *list = rule->private;
+	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
+}		
+
+
+/**
+ * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @var: hw_params variable to apply the list constraint
+ * @l: list
+ * 
+ * Apply the list of constraints to an interval parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
+			       unsigned int cond,
+			       snd_pcm_hw_param_t var,
+			       const struct snd_pcm_hw_constraint_list *l)
+{
+	return snd_pcm_hw_rule_add(runtime, cond, var,
+				   snd_pcm_hw_rule_list, (void *)l,
+				   var, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
+
+static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
+				  struct snd_pcm_hw_rule *rule)
+{
+	struct snd_pcm_hw_constraint_ranges *r = rule->private;
+	return snd_interval_ranges(hw_param_interval(params, rule->var),
+				   r->count, r->ranges, r->mask);
+}
+
+
+/**
+ * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @var: hw_params variable to apply the list of range constraints
+ * @r: ranges
+ *
+ * Apply the list of range constraints to an interval parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
+				 unsigned int cond,
+				 snd_pcm_hw_param_t var,
+				 const struct snd_pcm_hw_constraint_ranges *r)
+{
+	return snd_pcm_hw_rule_add(runtime, cond, var,
+				   snd_pcm_hw_rule_ranges, (void *)r,
+				   var, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
+
+static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
+				   struct snd_pcm_hw_rule *rule)
+{
+	const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
+	unsigned int num = 0, den = 0;
+	int err;
+	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
+				  r->nrats, r->rats, &num, &den);
+	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
+		params->rate_num = num;
+		params->rate_den = den;
+	}
+	return err;
+}
+
+/**
+ * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @var: hw_params variable to apply the ratnums constraint
+ * @r: struct snd_ratnums constriants
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, 
+				  unsigned int cond,
+				  snd_pcm_hw_param_t var,
+				  const struct snd_pcm_hw_constraint_ratnums *r)
+{
+	return snd_pcm_hw_rule_add(runtime, cond, var,
+				   snd_pcm_hw_rule_ratnums, (void *)r,
+				   var, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
+
+static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
+				   struct snd_pcm_hw_rule *rule)
+{
+	const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
+	unsigned int num = 0, den = 0;
+	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
+				  r->nrats, r->rats, &num, &den);
+	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
+		params->rate_num = num;
+		params->rate_den = den;
+	}
+	return err;
+}
+
+/**
+ * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @var: hw_params variable to apply the ratdens constraint
+ * @r: struct snd_ratdens constriants
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, 
+				  unsigned int cond,
+				  snd_pcm_hw_param_t var,
+				  const struct snd_pcm_hw_constraint_ratdens *r)
+{
+	return snd_pcm_hw_rule_add(runtime, cond, var,
+				   snd_pcm_hw_rule_ratdens, (void *)r,
+				   var, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
+
+static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
+				  struct snd_pcm_hw_rule *rule)
+{
+	unsigned int l = (unsigned long) rule->private;
+	int width = l & 0xffff;
+	unsigned int msbits = l >> 16;
+	const struct snd_interval *i =
+		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
+
+	if (!snd_interval_single(i))
+		return 0;
+
+	if ((snd_interval_value(i) == width) ||
+	    (width == 0 && snd_interval_value(i) > msbits))
+		params->msbits = min_not_zero(params->msbits, msbits);
+
+	return 0;
+}
+
+/**
+ * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @width: sample bits width
+ * @msbits: msbits width
+ *
+ * This constraint will set the number of most significant bits (msbits) if a
+ * sample format with the specified width has been select. If width is set to 0
+ * the msbits will be set for any sample format with a width larger than the
+ * specified msbits.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, 
+				 unsigned int cond,
+				 unsigned int width,
+				 unsigned int msbits)
+{
+	unsigned long l = (msbits << 16) | width;
+	return snd_pcm_hw_rule_add(runtime, cond, -1,
+				    snd_pcm_hw_rule_msbits,
+				    (void*) l,
+				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
+
+static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
+				struct snd_pcm_hw_rule *rule)
+{
+	unsigned long step = (unsigned long) rule->private;
+	return snd_interval_step(hw_param_interval(params, rule->var), step);
+}
+
+/**
+ * snd_pcm_hw_constraint_step - add a hw constraint step rule
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @var: hw_params variable to apply the step constraint
+ * @step: step size
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
+			       unsigned int cond,
+			       snd_pcm_hw_param_t var,
+			       unsigned long step)
+{
+	return snd_pcm_hw_rule_add(runtime, cond, var, 
+				   snd_pcm_hw_rule_step, (void *) step,
+				   var, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
+
+static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
+{
+	static const unsigned int pow2_sizes[] = {
+		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
+		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
+		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
+		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
+	};
+	return snd_interval_list(hw_param_interval(params, rule->var),
+				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
+}		
+
+/**
+ * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
+ * @runtime: PCM runtime instance
+ * @cond: condition bits
+ * @var: hw_params variable to apply the power-of-2 constraint
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
+			       unsigned int cond,
+			       snd_pcm_hw_param_t var)
+{
+	return snd_pcm_hw_rule_add(runtime, cond, var, 
+				   snd_pcm_hw_rule_pow2, NULL,
+				   var, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
+
+static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
+					   struct snd_pcm_hw_rule *rule)
+{
+	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
+	struct snd_interval *rate;
+
+	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+	return snd_interval_list(rate, 1, &base_rate, 0);
+}
+
+/**
+ * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
+ * @runtime: PCM runtime instance
+ * @base_rate: the rate at which the hardware does not resample
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
+			       unsigned int base_rate)
+{
+	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
+				   SNDRV_PCM_HW_PARAM_RATE,
+				   snd_pcm_hw_rule_noresample_func,
+				   (void *)(uintptr_t)base_rate,
+				   SNDRV_PCM_HW_PARAM_RATE, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
+
+static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
+				  snd_pcm_hw_param_t var)
+{
+	if (hw_is_mask(var)) {
+		snd_mask_any(hw_param_mask(params, var));
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+		return;
+	}
+	if (hw_is_interval(var)) {
+		snd_interval_any(hw_param_interval(params, var));
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+		return;
+	}
+	snd_BUG();
+}
+
+void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
+{
+	unsigned int k;
+	memset(params, 0, sizeof(*params));
+	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
+		_snd_pcm_hw_param_any(params, k);
+	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
+		_snd_pcm_hw_param_any(params, k);
+	params->info = ~0U;
+}
+EXPORT_SYMBOL(_snd_pcm_hw_params_any);
+
+/**
+ * snd_pcm_hw_param_value - return @params field @var value
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @dir: pointer to the direction (-1,0,1) or %NULL
+ *
+ * Return: The value for field @var if it's fixed in configuration space
+ * defined by @params. -%EINVAL otherwise.
+ */
+int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
+			   snd_pcm_hw_param_t var, int *dir)
+{
+	if (hw_is_mask(var)) {
+		const struct snd_mask *mask = hw_param_mask_c(params, var);
+		if (!snd_mask_single(mask))
+			return -EINVAL;
+		if (dir)
+			*dir = 0;
+		return snd_mask_value(mask);
+	}
+	if (hw_is_interval(var)) {
+		const struct snd_interval *i = hw_param_interval_c(params, var);
+		if (!snd_interval_single(i))
+			return -EINVAL;
+		if (dir)
+			*dir = i->openmin;
+		return snd_interval_value(i);
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL(snd_pcm_hw_param_value);
+
+void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
+				snd_pcm_hw_param_t var)
+{
+	if (hw_is_mask(var)) {
+		snd_mask_none(hw_param_mask(params, var));
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	} else if (hw_is_interval(var)) {
+		snd_interval_none(hw_param_interval(params, var));
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	} else {
+		snd_BUG();
+	}
+}
+EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
+
+static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
+				   snd_pcm_hw_param_t var)
+{
+	int changed;
+	if (hw_is_mask(var))
+		changed = snd_mask_refine_first(hw_param_mask(params, var));
+	else if (hw_is_interval(var))
+		changed = snd_interval_refine_first(hw_param_interval(params, var));
+	else
+		return -EINVAL;
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+
+
+/**
+ * snd_pcm_hw_param_first - refine config space and return minimum value
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @dir: pointer to the direction (-1,0,1) or %NULL
+ *
+ * Inside configuration space defined by @params remove from @var all
+ * values > minimum. Reduce configuration space accordingly.
+ *
+ * Return: The minimum, or a negative error code on failure.
+ */
+int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, 
+			   struct snd_pcm_hw_params *params, 
+			   snd_pcm_hw_param_t var, int *dir)
+{
+	int changed = _snd_pcm_hw_param_first(params, var);
+	if (changed < 0)
+		return changed;
+	if (params->rmask) {
+		int err = snd_pcm_hw_refine(pcm, params);
+		if (err < 0)
+			return err;
+	}
+	return snd_pcm_hw_param_value(params, var, dir);
+}
+EXPORT_SYMBOL(snd_pcm_hw_param_first);
+
+static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
+				  snd_pcm_hw_param_t var)
+{
+	int changed;
+	if (hw_is_mask(var))
+		changed = snd_mask_refine_last(hw_param_mask(params, var));
+	else if (hw_is_interval(var))
+		changed = snd_interval_refine_last(hw_param_interval(params, var));
+	else
+		return -EINVAL;
+	if (changed > 0) {
+		params->cmask |= 1 << var;
+		params->rmask |= 1 << var;
+	}
+	return changed;
+}
+
+
+/**
+ * snd_pcm_hw_param_last - refine config space and return maximum value
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ * @var: parameter to retrieve
+ * @dir: pointer to the direction (-1,0,1) or %NULL
+ *
+ * Inside configuration space defined by @params remove from @var all
+ * values < maximum. Reduce configuration space accordingly.
+ *
+ * Return: The maximum, or a negative error code on failure.
+ */
+int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm, 
+			  struct snd_pcm_hw_params *params,
+			  snd_pcm_hw_param_t var, int *dir)
+{
+	int changed = _snd_pcm_hw_param_last(params, var);
+	if (changed < 0)
+		return changed;
+	if (params->rmask) {
+		int err = snd_pcm_hw_refine(pcm, params);
+		if (err < 0)
+			return err;
+	}
+	return snd_pcm_hw_param_value(params, var, dir);
+}
+EXPORT_SYMBOL(snd_pcm_hw_param_last);
+
+static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
+				   void *arg)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	unsigned long flags;
+	snd_pcm_stream_lock_irqsave(substream, flags);
+	if (snd_pcm_running(substream) &&
+	    snd_pcm_update_hw_ptr(substream) >= 0)
+		runtime->status->hw_ptr %= runtime->buffer_size;
+	else {
+		runtime->status->hw_ptr = 0;
+		runtime->hw_ptr_wrap = 0;
+	}
+	snd_pcm_stream_unlock_irqrestore(substream, flags);
+	return 0;
+}
+
+static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
+					  void *arg)
+{
+	struct snd_pcm_channel_info *info = arg;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int width;
+	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
+		info->offset = -1;
+		return 0;
+	}
+	width = snd_pcm_format_physical_width(runtime->format);
+	if (width < 0)
+		return width;
+	info->offset = 0;
+	switch (runtime->access) {
+	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
+	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
+		info->first = info->channel * width;
+		info->step = runtime->channels * width;
+		break;
+	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
+	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
+	{
+		size_t size = runtime->dma_bytes / runtime->channels;
+		info->first = info->channel * size * 8;
+		info->step = width;
+		break;
+	}
+	default:
+		snd_BUG();
+		break;
+	}
+	return 0;
+}
+
+static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
+				       void *arg)
+{
+	struct snd_pcm_hw_params *params = arg;
+	snd_pcm_format_t format;
+	int channels;
+	ssize_t frame_size;
+
+	params->fifo_size = substream->runtime->hw.fifo_size;
+	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
+		format = params_format(params);
+		channels = params_channels(params);
+		frame_size = snd_pcm_format_size(format, channels);
+		if (frame_size > 0)
+			params->fifo_size /= frame_size;
+	}
+	return 0;
+}
+
+/**
+ * snd_pcm_lib_ioctl - a generic PCM ioctl callback
+ * @substream: the pcm substream instance
+ * @cmd: ioctl command
+ * @arg: ioctl argument
+ *
+ * Processes the generic ioctl commands for PCM.
+ * Can be passed as the ioctl callback for PCM ops.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
+		      unsigned int cmd, void *arg)
+{
+	switch (cmd) {
+	case SNDRV_PCM_IOCTL1_RESET:
+		return snd_pcm_lib_ioctl_reset(substream, arg);
+	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
+		return snd_pcm_lib_ioctl_channel_info(substream, arg);
+	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
+		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
+	}
+	return -ENXIO;
+}
+EXPORT_SYMBOL(snd_pcm_lib_ioctl);
+
+/**
+ * snd_pcm_period_elapsed_under_stream_lock() - update the status of runtime for the next period
+ *						under acquired lock of PCM substream.
+ * @substream: the instance of pcm substream.
+ *
+ * This function is called when the batch of audio data frames as the same size as the period of
+ * buffer is already processed in audio data transmission.
+ *
+ * The call of function updates the status of runtime with the latest position of audio data
+ * transmission, checks overrun and underrun over buffer, awaken user processes from waiting for
+ * available audio data frames, sampling audio timestamp, and performs stop or drain the PCM
+ * substream according to configured threshold.
+ *
+ * The function is intended to use for the case that PCM driver operates audio data frames under
+ * acquired lock of PCM substream; e.g. in callback of any operation of &snd_pcm_ops in process
+ * context. In any interrupt context, it's preferrable to use ``snd_pcm_period_elapsed()`` instead
+ * since lock of PCM substream should be acquired in advance.
+ *
+ * Developer should pay enough attention that some callbacks in &snd_pcm_ops are done by the call of
+ * function:
+ *
+ * - .pointer - to retrieve current position of audio data transmission by frame count or XRUN state.
+ * - .trigger - with SNDRV_PCM_TRIGGER_STOP at XRUN or DRAINING state.
+ * - .get_time_info - to retrieve audio time stamp if needed.
+ *
+ * Even if more than one periods have elapsed since the last call, you have to call this only once.
+ */
+void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return;
+	runtime = substream->runtime;
+
+	if (!snd_pcm_running(substream) ||
+	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
+		goto _end;
+
+#ifdef CONFIG_SND_PCM_TIMER
+	if (substream->timer_running)
+		snd_timer_interrupt(substream->timer, 1);
+#endif
+ _end:
+	snd_kill_fasync(runtime->fasync, SIGIO, POLL_IN);
+}
+EXPORT_SYMBOL(snd_pcm_period_elapsed_under_stream_lock);
+
+/**
+ * snd_pcm_period_elapsed() - update the status of runtime for the next period by acquiring lock of
+ *			      PCM substream.
+ * @substream: the instance of PCM substream.
+ *
+ * This function is mostly similar to ``snd_pcm_period_elapsed_under_stream_lock()`` except for
+ * acquiring lock of PCM substream voluntarily.
+ *
+ * It's typically called by any type of IRQ handler when hardware IRQ occurs to notify event that
+ * the batch of audio data frames as the same size as the period of buffer is already processed in
+ * audio data transmission.
+ */
+void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!substream))
+		return;
+
+	snd_pcm_stream_lock_irqsave(substream, flags);
+	snd_pcm_period_elapsed_under_stream_lock(substream);
+	snd_pcm_stream_unlock_irqrestore(substream, flags);
+}
+EXPORT_SYMBOL(snd_pcm_period_elapsed);
+
+/*
+ * Wait until avail_min data becomes available
+ * Returns a negative error code if any error occurs during operation.
+ * The available space is stored on availp.  When err = 0 and avail = 0
+ * on the capture stream, it indicates the stream is in DRAINING state.
+ */
+static int wait_for_avail(struct snd_pcm_substream *substream,
+			      snd_pcm_uframes_t *availp)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	wait_queue_entry_t wait;
+	int err = 0;
+	snd_pcm_uframes_t avail = 0;
+	long wait_time, tout;
+
+	init_waitqueue_entry(&wait, current);
+	set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&runtime->tsleep, &wait);
+
+	if (runtime->no_period_wakeup)
+		wait_time = MAX_SCHEDULE_TIMEOUT;
+	else {
+		/* use wait time from substream if available */
+		if (substream->wait_time) {
+			wait_time = substream->wait_time;
+		} else {
+			wait_time = 100;
+
+			if (runtime->rate) {
+				long t = runtime->buffer_size * 1100 / runtime->rate;
+				wait_time = max(t, wait_time);
+			}
+		}
+		wait_time = msecs_to_jiffies(wait_time);
+	}
+
+	for (;;) {
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+
+		/*
+		 * We need to check if space became available already
+		 * (and thus the wakeup happened already) first to close
+		 * the race of space already having become available.
+		 * This check must happen after been added to the waitqueue
+		 * and having current state be INTERRUPTIBLE.
+		 */
+		avail = snd_pcm_avail(substream);
+		if (avail >= runtime->twake)
+			break;
+		snd_pcm_stream_unlock_irq(substream);
+
+		tout = schedule_timeout(wait_time);
+
+		snd_pcm_stream_lock_irq(substream);
+		set_current_state(TASK_INTERRUPTIBLE);
+		switch (runtime->state) {
+		case SNDRV_PCM_STATE_SUSPENDED:
+			err = -ESTRPIPE;
+			goto _endloop;
+		case SNDRV_PCM_STATE_XRUN:
+			err = -EPIPE;
+			goto _endloop;
+		case SNDRV_PCM_STATE_DRAINING:
+			if (is_playback)
+				err = -EPIPE;
+			else 
+				avail = 0; /* indicate draining */
+			goto _endloop;
+		case SNDRV_PCM_STATE_OPEN:
+		case SNDRV_PCM_STATE_SETUP:
+		case SNDRV_PCM_STATE_DISCONNECTED:
+			err = -EBADFD;
+			goto _endloop;
+		case SNDRV_PCM_STATE_PAUSED:
+			continue;
+		}
+		if (!tout) {
+			pcm_dbg(substream->pcm,
+				"%s timeout (DMA or IRQ trouble?)\n",
+				is_playback ? "playback write" : "capture read");
+			err = -EIO;
+			break;
+		}
+	}
+ _endloop:
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&runtime->tsleep, &wait);
+	*availp = avail;
+	return err;
+}
+	
+typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
+			      int channel, unsigned long hwoff,
+			      struct iov_iter *iter, unsigned long bytes);
+
+typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
+			  snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f,
+			  bool);
+
+/* calculate the target DMA-buffer position to be written/read */
+static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
+			   int channel, unsigned long hwoff)
+{
+	return runtime->dma_area + hwoff +
+		channel * (runtime->dma_bytes / runtime->channels);
+}
+
+/* default copy ops for write; used for both interleaved and non- modes */
+static int default_write_copy(struct snd_pcm_substream *substream,
+			      int channel, unsigned long hwoff,
+			      struct iov_iter *iter, unsigned long bytes)
+{
+	if (copy_from_iter(get_dma_ptr(substream->runtime, channel, hwoff),
+			   bytes, iter) != bytes)
+		return -EFAULT;
+	return 0;
+}
+
+/* fill silence instead of copy data; called as a transfer helper
+ * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
+ * a NULL buffer is passed
+ */
+static int fill_silence(struct snd_pcm_substream *substream, int channel,
+			unsigned long hwoff, struct iov_iter *iter,
+			unsigned long bytes)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return 0;
+	if (substream->ops->fill_silence)
+		return substream->ops->fill_silence(substream, channel,
+						    hwoff, bytes);
+
+	snd_pcm_format_set_silence(runtime->format,
+				   get_dma_ptr(runtime, channel, hwoff),
+				   bytes_to_samples(runtime, bytes));
+	return 0;
+}
+
+/* default copy ops for read; used for both interleaved and non- modes */
+static int default_read_copy(struct snd_pcm_substream *substream,
+			     int channel, unsigned long hwoff,
+			     struct iov_iter *iter, unsigned long bytes)
+{
+	if (copy_to_iter(get_dma_ptr(substream->runtime, channel, hwoff),
+			 bytes, iter) != bytes)
+		return -EFAULT;
+	return 0;
+}
+
+/* call transfer with the filled iov_iter */
+static int do_transfer(struct snd_pcm_substream *substream, int c,
+		       unsigned long hwoff, void *data, unsigned long bytes,
+		       pcm_transfer_f transfer, bool in_kernel)
+{
+	struct iov_iter iter;
+	int err, type;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		type = ITER_SOURCE;
+	else
+		type = ITER_DEST;
+
+	if (in_kernel) {
+		struct kvec kvec = { data, bytes };
+
+		iov_iter_kvec(&iter, type, &kvec, 1, bytes);
+		return transfer(substream, c, hwoff, &iter, bytes);
+	}
+
+	err = import_ubuf(type, (__force void __user *)data, bytes, &iter);
+	if (err)
+		return err;
+	return transfer(substream, c, hwoff, &iter, bytes);
+}
+
+/* call transfer function with the converted pointers and sizes;
+ * for interleaved mode, it's one shot for all samples
+ */
+static int interleaved_copy(struct snd_pcm_substream *substream,
+			    snd_pcm_uframes_t hwoff, void *data,
+			    snd_pcm_uframes_t off,
+			    snd_pcm_uframes_t frames,
+			    pcm_transfer_f transfer,
+			    bool in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	/* convert to bytes */
+	hwoff = frames_to_bytes(runtime, hwoff);
+	off = frames_to_bytes(runtime, off);
+	frames = frames_to_bytes(runtime, frames);
+
+	return do_transfer(substream, 0, hwoff, data + off, frames, transfer,
+			   in_kernel);
+}
+
+/* call transfer function with the converted pointers and sizes for each
+ * non-interleaved channel; when buffer is NULL, silencing instead of copying
+ */
+static int noninterleaved_copy(struct snd_pcm_substream *substream,
+			       snd_pcm_uframes_t hwoff, void *data,
+			       snd_pcm_uframes_t off,
+			       snd_pcm_uframes_t frames,
+			       pcm_transfer_f transfer,
+			       bool in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int channels = runtime->channels;
+	void **bufs = data;
+	int c, err;
+
+	/* convert to bytes; note that it's not frames_to_bytes() here.
+	 * in non-interleaved mode, we copy for each channel, thus
+	 * each copy is n_samples bytes x channels = whole frames.
+	 */
+	off = samples_to_bytes(runtime, off);
+	frames = samples_to_bytes(runtime, frames);
+	hwoff = samples_to_bytes(runtime, hwoff);
+	for (c = 0; c < channels; ++c, ++bufs) {
+		if (!data || !*bufs)
+			err = fill_silence(substream, c, hwoff, NULL, frames);
+		else
+			err = do_transfer(substream, c, hwoff, *bufs + off,
+					  frames, transfer, in_kernel);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/* fill silence on the given buffer position;
+ * called from snd_pcm_playback_silence()
+ */
+static int fill_silence_frames(struct snd_pcm_substream *substream,
+			       snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
+{
+	if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
+	    substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
+		return interleaved_copy(substream, off, NULL, 0, frames,
+					fill_silence, true);
+	else
+		return noninterleaved_copy(substream, off, NULL, 0, frames,
+					   fill_silence, true);
+}
+
+/* sanity-check for read/write methods */
+static int pcm_sanity_check(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
+		return -EINVAL;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+	return 0;
+}
+
+static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
+{
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_RUNNING:
+	case SNDRV_PCM_STATE_PAUSED:
+		return 0;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
+	case SNDRV_PCM_STATE_SUSPENDED:
+		return -ESTRPIPE;
+	default:
+		return -EBADFD;
+	}
+}
+
+/* update to the given appl_ptr and call ack callback if needed;
+ * when an error is returned, take back to the original value
+ */
+int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
+			   snd_pcm_uframes_t appl_ptr)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
+	snd_pcm_sframes_t diff;
+	int ret;
+
+	if (old_appl_ptr == appl_ptr)
+		return 0;
+
+	if (appl_ptr >= runtime->boundary)
+		return -EINVAL;
+	/*
+	 * check if a rewind is requested by the application
+	 */
+	if (substream->runtime->info & SNDRV_PCM_INFO_NO_REWINDS) {
+		diff = appl_ptr - old_appl_ptr;
+		if (diff >= 0) {
+			if (diff > runtime->buffer_size)
+				return -EINVAL;
+		} else {
+			if (runtime->boundary + diff > runtime->buffer_size)
+				return -EINVAL;
+		}
+	}
+
+	runtime->control->appl_ptr = appl_ptr;
+	if (substream->ops->ack) {
+		ret = substream->ops->ack(substream);
+		if (ret < 0) {
+			runtime->control->appl_ptr = old_appl_ptr;
+			if (ret == -EPIPE)
+				__snd_pcm_xrun(substream);
+			return ret;
+		}
+	}
+
+	trace_applptr(substream, old_appl_ptr, appl_ptr);
+
+	return 0;
+}
+
+/* the common loop for read/write data */
+snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
+				     void *data, bool interleaved,
+				     snd_pcm_uframes_t size, bool in_kernel)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t xfer = 0;
+	snd_pcm_uframes_t offset = 0;
+	snd_pcm_uframes_t avail;
+	pcm_copy_f writer;
+	pcm_transfer_f transfer;
+	bool nonblock;
+	bool is_playback;
+	int err;
+
+	err = pcm_sanity_check(substream);
+	if (err < 0)
+		return err;
+
+	is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	if (interleaved) {
+		if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
+		    runtime->channels > 1)
+			return -EINVAL;
+		writer = interleaved_copy;
+	} else {
+		if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
+			return -EINVAL;
+		writer = noninterleaved_copy;
+	}
+
+	if (!data) {
+		if (is_playback)
+			transfer = fill_silence;
+		else
+			return -EINVAL;
+	} else {
+		if (substream->ops->copy)
+			transfer = substream->ops->copy;
+		else
+			transfer = is_playback ?
+				default_write_copy : default_read_copy;
+	}
+
+	if (size == 0)
+		return 0;
+
+	nonblock = !!(substream->f_flags & O_NONBLOCK);
+
+	snd_pcm_stream_lock_irq(substream);
+	err = pcm_accessible_state(runtime);
+	if (err < 0)
+		goto _end_unlock;
+
+	runtime->twake = runtime->control->avail_min ? : 1;
+	if (runtime->state == SNDRV_PCM_STATE_RUNNING)
+		snd_pcm_update_hw_ptr(substream);
+
+	/*
+	 * If size < start_threshold, wait indefinitely. Another
+	 * thread may start capture
+	 */
+	if (!is_playback &&
+	    runtime->state == SNDRV_PCM_STATE_PREPARED &&
+	    size >= runtime->start_threshold) {
+		err = snd_pcm_start(substream);
+		if (err < 0)
+			goto _end_unlock;
+	}
+
+	avail = snd_pcm_avail(substream);
+
+	while (size > 0) {
+		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
+		snd_pcm_uframes_t cont;
+		if (!avail) {
+			if (!is_playback &&
+			    runtime->state == SNDRV_PCM_STATE_DRAINING) {
+				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
+				goto _end_unlock;
+			}
+			if (nonblock) {
+				err = -EAGAIN;
+				goto _end_unlock;
+			}
+			runtime->twake = min_t(snd_pcm_uframes_t, size,
+					runtime->control->avail_min ? : 1);
+			err = wait_for_avail(substream, &avail);
+			if (err < 0)
+				goto _end_unlock;
+			if (!avail)
+				continue; /* draining */
+		}
+		frames = size > avail ? avail : size;
+		appl_ptr = READ_ONCE(runtime->control->appl_ptr);
+		appl_ofs = appl_ptr % runtime->buffer_size;
+		cont = runtime->buffer_size - appl_ofs;
+		if (frames > cont)
+			frames = cont;
+		if (snd_BUG_ON(!frames)) {
+			err = -EINVAL;
+			goto _end_unlock;
+		}
+		if (!atomic_inc_unless_negative(&runtime->buffer_accessing)) {
+			err = -EBUSY;
+			goto _end_unlock;
+		}
+		snd_pcm_stream_unlock_irq(substream);
+		if (!is_playback)
+			snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
+		err = writer(substream, appl_ofs, data, offset, frames,
+			     transfer, in_kernel);
+		if (is_playback)
+			snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+		snd_pcm_stream_lock_irq(substream);
+		atomic_dec(&runtime->buffer_accessing);
+		if (err < 0)
+			goto _end_unlock;
+		err = pcm_accessible_state(runtime);
+		if (err < 0)
+			goto _end_unlock;
+		appl_ptr += frames;
+		if (appl_ptr >= runtime->boundary)
+			appl_ptr -= runtime->boundary;
+		err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
+		if (err < 0)
+			goto _end_unlock;
+
+		offset += frames;
+		size -= frames;
+		xfer += frames;
+		avail -= frames;
+		if (is_playback &&
+		    runtime->state == SNDRV_PCM_STATE_PREPARED &&
+		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
+			err = snd_pcm_start(substream);
+			if (err < 0)
+				goto _end_unlock;
+		}
+	}
+ _end_unlock:
+	runtime->twake = 0;
+	if (xfer > 0 && err >= 0)
+		snd_pcm_update_state(substream, runtime);
+	snd_pcm_stream_unlock_irq(substream);
+	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
+}
+EXPORT_SYMBOL(__snd_pcm_lib_xfer);
+
+/*
+ * standard channel mapping helpers
+ */
+
+/* default channel maps for multi-channel playbacks, up to 8 channels */
+const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
+	{ .channels = 1,
+	  .map = { SNDRV_CHMAP_MONO } },
+	{ .channels = 2,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
+	{ .channels = 4,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
+		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
+	{ .channels = 6,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
+		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
+		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
+	{ .channels = 8,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
+		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
+		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
+		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
+	{ }
+};
+EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
+
+/* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
+const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
+	{ .channels = 1,
+	  .map = { SNDRV_CHMAP_MONO } },
+	{ .channels = 2,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
+	{ .channels = 4,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
+		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
+	{ .channels = 6,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
+		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
+		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
+	{ .channels = 8,
+	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
+		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
+		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
+		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
+	{ }
+};
+EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
+
+static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
+{
+	if (ch > info->max_channels)
+		return false;
+	return !info->channel_mask || (info->channel_mask & (1U << ch));
+}
+
+static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_info *uinfo)
+{
+	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = info->max_channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
+	return 0;
+}
+
+/* get callback for channel map ctl element
+ * stores the channel position firstly matching with the current channels
+ */
+static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
+			     struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
+	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
+	struct snd_pcm_substream *substream;
+	const struct snd_pcm_chmap_elem *map;
+
+	if (!info->chmap)
+		return -EINVAL;
+	substream = snd_pcm_chmap_substream(info, idx);
+	if (!substream)
+		return -ENODEV;
+	memset(ucontrol->value.integer.value, 0,
+	       sizeof(long) * info->max_channels);
+	if (!substream->runtime)
+		return 0; /* no channels set */
+	for (map = info->chmap; map->channels; map++) {
+		int i;
+		if (map->channels == substream->runtime->channels &&
+		    valid_chmap_channels(info, map->channels)) {
+			for (i = 0; i < map->channels; i++)
+				ucontrol->value.integer.value[i] = map->map[i];
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+/* tlv callback for channel map ctl element
+ * expands the pre-defined channel maps in a form of TLV
+ */
+static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
+			     unsigned int size, unsigned int __user *tlv)
+{
+	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
+	const struct snd_pcm_chmap_elem *map;
+	unsigned int __user *dst;
+	int c, count = 0;
+
+	if (!info->chmap)
+		return -EINVAL;
+	if (size < 8)
+		return -ENOMEM;
+	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
+		return -EFAULT;
+	size -= 8;
+	dst = tlv + 2;
+	for (map = info->chmap; map->channels; map++) {
+		int chs_bytes = map->channels * 4;
+		if (!valid_chmap_channels(info, map->channels))
+			continue;
+		if (size < 8)
+			return -ENOMEM;
+		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
+		    put_user(chs_bytes, dst + 1))
+			return -EFAULT;
+		dst += 2;
+		size -= 8;
+		count += 8;
+		if (size < chs_bytes)
+			return -ENOMEM;
+		size -= chs_bytes;
+		count += chs_bytes;
+		for (c = 0; c < map->channels; c++) {
+			if (put_user(map->map[c], dst))
+				return -EFAULT;
+			dst++;
+		}
+	}
+	if (put_user(count, tlv + 1))
+		return -EFAULT;
+	return 0;
+}
+
+static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
+{
+	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
+	info->pcm->streams[info->stream].chmap_kctl = NULL;
+	kfree(info);
+}
+
+/**
+ * snd_pcm_add_chmap_ctls - create channel-mapping control elements
+ * @pcm: the assigned PCM instance
+ * @stream: stream direction
+ * @chmap: channel map elements (for query)
+ * @max_channels: the max number of channels for the stream
+ * @private_value: the value passed to each kcontrol's private_value field
+ * @info_ret: store struct snd_pcm_chmap instance if non-NULL
+ *
+ * Create channel-mapping control elements assigned to the given PCM stream(s).
+ * Return: Zero if successful, or a negative error value.
+ */
+int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
+			   const struct snd_pcm_chmap_elem *chmap,
+			   int max_channels,
+			   unsigned long private_value,
+			   struct snd_pcm_chmap **info_ret)
+{
+	struct snd_pcm_chmap *info;
+	struct snd_kcontrol_new knew = {
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
+		.access = SNDRV_CTL_ELEM_ACCESS_READ |
+			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
+			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
+		.info = pcm_chmap_ctl_info,
+		.get = pcm_chmap_ctl_get,
+		.tlv.c = pcm_chmap_ctl_tlv,
+	};
+	int err;
+
+	if (WARN_ON(pcm->streams[stream].chmap_kctl))
+		return -EBUSY;
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+	info->pcm = pcm;
+	info->stream = stream;
+	info->chmap = chmap;
+	info->max_channels = max_channels;
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+		knew.name = "Playback Channel Map";
+	else
+		knew.name = "Capture Channel Map";
+	knew.device = pcm->device;
+	knew.count = pcm->streams[stream].substream_count;
+	knew.private_value = private_value;
+	info->kctl = snd_ctl_new1(&knew, info);
+	if (!info->kctl) {
+		kfree(info);
+		return -ENOMEM;
+	}
+	info->kctl->private_free = pcm_chmap_ctl_private_free;
+	err = snd_ctl_add(pcm->card, info->kctl);
+	if (err < 0)
+		return err;
+	pcm->streams[stream].chmap_kctl = info->kctl;
+	if (info_ret)
+		*info_ret = info;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
diff --git a/sound/core/pcm_local.h b/sound/core/pcm_local.h
new file mode 100644
index 0000000000..ecb21697ae
--- /dev/null
+++ b/sound/core/pcm_local.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * pcm_local.h - a local header file for snd-pcm module.
+ *
+ * Copyright (c) Takashi Sakamoto <o-takashi@sakamocchi.jp>
+ */
+
+#ifndef __SOUND_CORE_PCM_LOCAL_H
+#define __SOUND_CORE_PCM_LOCAL_H
+
+extern const struct snd_pcm_hw_constraint_list snd_pcm_known_rates;
+
+void snd_interval_mul(const struct snd_interval *a,
+		      const struct snd_interval *b, struct snd_interval *c);
+void snd_interval_div(const struct snd_interval *a,
+		      const struct snd_interval *b, struct snd_interval *c);
+void snd_interval_muldivk(const struct snd_interval *a,
+			  const struct snd_interval *b,
+			  unsigned int k, struct snd_interval *c);
+void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
+			  const struct snd_interval *b, struct snd_interval *c);
+
+int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime,
+			       snd_pcm_hw_param_t var, u_int32_t mask);
+
+int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
+			   snd_pcm_uframes_t appl_ptr);
+int snd_pcm_update_state(struct snd_pcm_substream *substream,
+			 struct snd_pcm_runtime *runtime);
+int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream);
+
+void snd_pcm_playback_silence(struct snd_pcm_substream *substream,
+			      snd_pcm_uframes_t new_hw_ptr);
+
+static inline snd_pcm_uframes_t
+snd_pcm_avail(struct snd_pcm_substream *substream)
+{
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		return snd_pcm_playback_avail(substream->runtime);
+	else
+		return snd_pcm_capture_avail(substream->runtime);
+}
+
+static inline snd_pcm_uframes_t
+snd_pcm_hw_avail(struct snd_pcm_substream *substream)
+{
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		return snd_pcm_playback_hw_avail(substream->runtime);
+	else
+		return snd_pcm_capture_hw_avail(substream->runtime);
+}
+
+#ifdef CONFIG_SND_PCM_TIMER
+void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream);
+void snd_pcm_timer_init(struct snd_pcm_substream *substream);
+void snd_pcm_timer_done(struct snd_pcm_substream *substream);
+#else
+static inline void
+snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream) {}
+static inline void snd_pcm_timer_init(struct snd_pcm_substream *substream) {}
+static inline void snd_pcm_timer_done(struct snd_pcm_substream *substream) {}
+#endif
+
+void __snd_pcm_xrun(struct snd_pcm_substream *substream);
+void snd_pcm_group_init(struct snd_pcm_group *group);
+void snd_pcm_sync_stop(struct snd_pcm_substream *substream, bool sync_irq);
+
+#define PCM_RUNTIME_CHECK(sub) snd_BUG_ON(!(sub) || !(sub)->runtime)
+
+/* loop over all PCM substreams */
+#define for_each_pcm_substream(pcm, str, subs) \
+	for ((str) = 0; (str) < 2; (str)++) \
+		for ((subs) = (pcm)->streams[str].substream; (subs); \
+		     (subs) = (subs)->next)
+
+static inline void snd_pcm_dma_buffer_sync(struct snd_pcm_substream *substream,
+					   enum snd_dma_sync_mode mode)
+{
+	if (substream->runtime->info & SNDRV_PCM_INFO_EXPLICIT_SYNC)
+		snd_dma_buffer_sync(snd_pcm_get_dma_buf(substream), mode);
+}
+
+#endif	/* __SOUND_CORE_PCM_LOCAL_H */
diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
new file mode 100644
index 0000000000..a0b9514716
--- /dev/null
+++ b/sound/core/pcm_memory.c
@@ -0,0 +1,563 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/io.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/info.h>
+#include <sound/initval.h>
+#include "pcm_local.h"
+
+static int preallocate_dma = 1;
+module_param(preallocate_dma, int, 0444);
+MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
+
+static int maximum_substreams = 4;
+module_param(maximum_substreams, int, 0444);
+MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
+
+static const size_t snd_minimum_buffer = 16384;
+
+static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
+module_param(max_alloc_per_card, ulong, 0644);
+MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
+
+static void __update_allocated_size(struct snd_card *card, ssize_t bytes)
+{
+	card->total_pcm_alloc_bytes += bytes;
+}
+
+static void update_allocated_size(struct snd_card *card, ssize_t bytes)
+{
+	mutex_lock(&card->memory_mutex);
+	__update_allocated_size(card, bytes);
+	mutex_unlock(&card->memory_mutex);
+}
+
+static void decrease_allocated_size(struct snd_card *card, size_t bytes)
+{
+	mutex_lock(&card->memory_mutex);
+	WARN_ON(card->total_pcm_alloc_bytes < bytes);
+	__update_allocated_size(card, -(ssize_t)bytes);
+	mutex_unlock(&card->memory_mutex);
+}
+
+static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
+			  int str, size_t size, struct snd_dma_buffer *dmab)
+{
+	enum dma_data_direction dir;
+	int err;
+
+	/* check and reserve the requested size */
+	mutex_lock(&card->memory_mutex);
+	if (max_alloc_per_card &&
+	    card->total_pcm_alloc_bytes + size > max_alloc_per_card) {
+		mutex_unlock(&card->memory_mutex);
+		return -ENOMEM;
+	}
+	__update_allocated_size(card, size);
+	mutex_unlock(&card->memory_mutex);
+
+	if (str == SNDRV_PCM_STREAM_PLAYBACK)
+		dir = DMA_TO_DEVICE;
+	else
+		dir = DMA_FROM_DEVICE;
+	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
+	if (!err) {
+		/* the actual allocation size might be bigger than requested,
+		 * and we need to correct the account
+		 */
+		if (dmab->bytes != size)
+			update_allocated_size(card, dmab->bytes - size);
+	} else {
+		/* take back on allocation failure */
+		decrease_allocated_size(card, size);
+	}
+	return err;
+}
+
+static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
+{
+	if (!dmab->area)
+		return;
+	decrease_allocated_size(card, dmab->bytes);
+	snd_dma_free_pages(dmab);
+	dmab->area = NULL;
+}
+
+/*
+ * try to allocate as the large pages as possible.
+ * stores the resultant memory size in *res_size.
+ *
+ * the minimum size is snd_minimum_buffer.  it should be power of 2.
+ */
+static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
+				 size_t size, bool no_fallback)
+{
+	struct snd_dma_buffer *dmab = &substream->dma_buffer;
+	struct snd_card *card = substream->pcm->card;
+	size_t orig_size = size;
+	int err;
+
+	do {
+		err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
+				     substream->stream, size, dmab);
+		if (err != -ENOMEM)
+			return err;
+		if (no_fallback)
+			break;
+		size >>= 1;
+	} while (size >= snd_minimum_buffer);
+	dmab->bytes = 0; /* tell error */
+	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
+		substream->pcm->card->number, substream->pcm->device,
+		substream->stream ? 'c' : 'p', substream->number,
+		substream->pcm->name, orig_size);
+	return -ENOMEM;
+}
+
+/**
+ * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
+ * @substream: the pcm substream instance
+ *
+ * Releases the pre-allocated buffer of the given substream.
+ */
+void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
+{
+	do_free_pages(substream->pcm->card, &substream->dma_buffer);
+}
+
+/**
+ * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
+ * @pcm: the pcm instance
+ *
+ * Releases all the pre-allocated buffers on the given pcm.
+ */
+void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	int stream;
+
+	for_each_pcm_substream(pcm, stream, substream)
+		snd_pcm_lib_preallocate_free(substream);
+}
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
+
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+/*
+ * read callback for prealloc proc file
+ *
+ * prints the current allocated size in kB.
+ */
+static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
+					      struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
+}
+
+/*
+ * read callback for prealloc_max proc file
+ *
+ * prints the maximum allowed size in kB.
+ */
+static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
+						  struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
+}
+
+/*
+ * write callback for prealloc proc file
+ *
+ * accepts the preallocation size in kB.
+ */
+static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
+					       struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	struct snd_card *card = substream->pcm->card;
+	char line[64], str[64];
+	size_t size;
+	struct snd_dma_buffer new_dmab;
+
+	mutex_lock(&substream->pcm->open_mutex);
+	if (substream->runtime) {
+		buffer->error = -EBUSY;
+		goto unlock;
+	}
+	if (!snd_info_get_line(buffer, line, sizeof(line))) {
+		snd_info_get_str(str, line, sizeof(str));
+		size = simple_strtoul(str, NULL, 10) * 1024;
+		if ((size != 0 && size < 8192) || size > substream->dma_max) {
+			buffer->error = -EINVAL;
+			goto unlock;
+		}
+		if (substream->dma_buffer.bytes == size)
+			goto unlock;
+		memset(&new_dmab, 0, sizeof(new_dmab));
+		new_dmab.dev = substream->dma_buffer.dev;
+		if (size > 0) {
+			if (do_alloc_pages(card,
+					   substream->dma_buffer.dev.type,
+					   substream->dma_buffer.dev.dev,
+					   substream->stream,
+					   size, &new_dmab) < 0) {
+				buffer->error = -ENOMEM;
+				pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
+					 substream->pcm->card->number, substream->pcm->device,
+					 substream->stream ? 'c' : 'p', substream->number,
+					 substream->pcm->name, size);
+				goto unlock;
+			}
+			substream->buffer_bytes_max = size;
+		} else {
+			substream->buffer_bytes_max = UINT_MAX;
+		}
+		if (substream->dma_buffer.area)
+			do_free_pages(card, &substream->dma_buffer);
+		substream->dma_buffer = new_dmab;
+	} else {
+		buffer->error = -EINVAL;
+	}
+ unlock:
+	mutex_unlock(&substream->pcm->open_mutex);
+}
+
+static inline void preallocate_info_init(struct snd_pcm_substream *substream)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
+					   substream->proc_root);
+	if (entry) {
+		snd_info_set_text_ops(entry, substream,
+				      snd_pcm_lib_preallocate_proc_read);
+		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
+		entry->mode |= 0200;
+	}
+	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
+					   substream->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, substream,
+				      snd_pcm_lib_preallocate_max_proc_read);
+}
+
+#else /* !CONFIG_SND_VERBOSE_PROCFS */
+static inline void preallocate_info_init(struct snd_pcm_substream *substream)
+{
+}
+#endif /* CONFIG_SND_VERBOSE_PROCFS */
+
+/*
+ * pre-allocate the buffer and create a proc file for the substream
+ */
+static int preallocate_pages(struct snd_pcm_substream *substream,
+			      int type, struct device *data,
+			      size_t size, size_t max, bool managed)
+{
+	int err;
+
+	if (snd_BUG_ON(substream->dma_buffer.dev.type))
+		return -EINVAL;
+
+	substream->dma_buffer.dev.type = type;
+	substream->dma_buffer.dev.dev = data;
+
+	if (size > 0) {
+		if (!max) {
+			/* no fallback, only also inform -ENOMEM */
+			err = preallocate_pcm_pages(substream, size, true);
+			if (err < 0)
+				return err;
+		} else if (preallocate_dma &&
+			   substream->number < maximum_substreams) {
+			err = preallocate_pcm_pages(substream, size, false);
+			if (err < 0 && err != -ENOMEM)
+				return err;
+		}
+	}
+
+	if (substream->dma_buffer.bytes > 0)
+		substream->buffer_bytes_max = substream->dma_buffer.bytes;
+	substream->dma_max = max;
+	if (max > 0)
+		preallocate_info_init(substream);
+	if (managed)
+		substream->managed_buffer_alloc = 1;
+	return 0;
+}
+
+static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
+				      void *data, size_t size, size_t max,
+				      bool managed)
+{
+	struct snd_pcm_substream *substream;
+	int stream, err;
+
+	for_each_pcm_substream(pcm, stream, substream) {
+		err = preallocate_pages(substream, type, data, size, max, managed);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/**
+ * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
+ * @substream: the pcm substream instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation for the given DMA buffer type.
+ */
+void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
+				  int type, struct device *data,
+				  size_t size, size_t max)
+{
+	preallocate_pages(substream, type, data, size, max, false);
+}
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
+
+/**
+ * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
+ * @pcm: the pcm instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation to all substreams of the given pcm for the
+ * specified DMA type.
+ */
+void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
+					  int type, void *data,
+					  size_t size, size_t max)
+{
+	preallocate_pages_for_all(pcm, type, data, size, max, false);
+}
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
+
+/**
+ * snd_pcm_set_managed_buffer - set up buffer management for a substream
+ * @substream: the pcm substream instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation for the given DMA buffer type, and set the managed
+ * buffer allocation mode to the given substream.
+ * In this mode, PCM core will allocate a buffer automatically before PCM
+ * hw_params ops call, and release the buffer after PCM hw_free ops call
+ * as well, so that the driver doesn't need to invoke the allocation and
+ * the release explicitly in its callback.
+ * When a buffer is actually allocated before the PCM hw_params call, it
+ * turns on the runtime buffer_changed flag for drivers changing their h/w
+ * parameters accordingly.
+ *
+ * When @size is non-zero and @max is zero, this tries to allocate for only
+ * the exact buffer size without fallback, and may return -ENOMEM.
+ * Otherwise, the function tries to allocate smaller chunks if the allocation
+ * fails.  This is the behavior of snd_pcm_set_fixed_buffer().
+ *
+ * When both @size and @max are zero, the function only sets up the buffer
+ * for later dynamic allocations. It's used typically for buffers with
+ * SNDRV_DMA_TYPE_VMALLOC type.
+ *
+ * Upon successful buffer allocation and setup, the function returns 0.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
+				struct device *data, size_t size, size_t max)
+{
+	return preallocate_pages(substream, type, data, size, max, true);
+}
+EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
+
+/**
+ * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
+ *	for all substreams
+ * @pcm: the pcm instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation to all substreams of the given pcm for the specified DMA
+ * type and size, and set the managed_buffer_alloc flag to each substream.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
+				   struct device *data,
+				   size_t size, size_t max)
+{
+	return preallocate_pages_for_all(pcm, type, data, size, max, true);
+}
+EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
+
+/**
+ * snd_pcm_lib_malloc_pages - allocate the DMA buffer
+ * @substream: the substream to allocate the DMA buffer to
+ * @size: the requested buffer size in bytes
+ *
+ * Allocates the DMA buffer on the BUS type given earlier to
+ * snd_pcm_lib_preallocate_xxx_pages().
+ *
+ * Return: 1 if the buffer is changed, 0 if not changed, or a negative
+ * code on failure.
+ */
+int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
+{
+	struct snd_card *card;
+	struct snd_pcm_runtime *runtime;
+	struct snd_dma_buffer *dmab = NULL;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
+		       SNDRV_DMA_TYPE_UNKNOWN))
+		return -EINVAL;
+	runtime = substream->runtime;
+	card = substream->pcm->card;
+
+	if (runtime->dma_buffer_p) {
+		/* perphaps, we might free the large DMA memory region
+		   to save some space here, but the actual solution
+		   costs us less time */
+		if (runtime->dma_buffer_p->bytes >= size) {
+			runtime->dma_bytes = size;
+			return 0;	/* ok, do not change */
+		}
+		snd_pcm_lib_free_pages(substream);
+	}
+	if (substream->dma_buffer.area != NULL &&
+	    substream->dma_buffer.bytes >= size) {
+		dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
+	} else {
+		/* dma_max=0 means the fixed size preallocation */
+		if (substream->dma_buffer.area && !substream->dma_max)
+			return -ENOMEM;
+		dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
+		if (! dmab)
+			return -ENOMEM;
+		dmab->dev = substream->dma_buffer.dev;
+		if (do_alloc_pages(card,
+				   substream->dma_buffer.dev.type,
+				   substream->dma_buffer.dev.dev,
+				   substream->stream,
+				   size, dmab) < 0) {
+			kfree(dmab);
+			pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
+				 substream->pcm->card->number, substream->pcm->device,
+				 substream->stream ? 'c' : 'p', substream->number,
+				 substream->pcm->name, size);
+			return -ENOMEM;
+		}
+	}
+	snd_pcm_set_runtime_buffer(substream, dmab);
+	runtime->dma_bytes = size;
+	return 1;			/* area was changed */
+}
+EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
+
+/**
+ * snd_pcm_lib_free_pages - release the allocated DMA buffer.
+ * @substream: the substream to release the DMA buffer
+ *
+ * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	runtime = substream->runtime;
+	if (runtime->dma_area == NULL)
+		return 0;
+	if (runtime->dma_buffer_p != &substream->dma_buffer) {
+		struct snd_card *card = substream->pcm->card;
+
+		/* it's a newly allocated buffer.  release it now. */
+		do_free_pages(card, runtime->dma_buffer_p);
+		kfree(runtime->dma_buffer_p);
+	}
+	snd_pcm_set_runtime_buffer(substream, NULL);
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_lib_free_pages);
+
+int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
+				      size_t size, gfp_t gfp_flags)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	runtime = substream->runtime;
+	if (runtime->dma_area) {
+		if (runtime->dma_bytes >= size)
+			return 0; /* already large enough */
+		vfree(runtime->dma_area);
+	}
+	runtime->dma_area = __vmalloc(size, gfp_flags);
+	if (!runtime->dma_area)
+		return -ENOMEM;
+	runtime->dma_bytes = size;
+	return 1;
+}
+EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
+
+/**
+ * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
+ * @substream: the substream with a buffer allocated by
+ *	snd_pcm_lib_alloc_vmalloc_buffer()
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	runtime = substream->runtime;
+	vfree(runtime->dma_area);
+	runtime->dma_area = NULL;
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
+
+/**
+ * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
+ * @substream: the substream with a buffer allocated by
+ *	snd_pcm_lib_alloc_vmalloc_buffer()
+ * @offset: offset in the buffer
+ *
+ * This function is to be used as the page callback in the PCM ops.
+ *
+ * Return: The page struct, or %NULL on failure.
+ */
+struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
+					  unsigned long offset)
+{
+	return vmalloc_to_page(substream->runtime->dma_area + offset);
+}
+EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c
new file mode 100644
index 0000000000..5588b6a1ee
--- /dev/null
+++ b/sound/core/pcm_misc.c
@@ -0,0 +1,616 @@
+/*
+ *  PCM Interface - misc routines
+ *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2 of
+ *   the License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+  
+#include <linux/time.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "pcm_local.h"
+
+#define SND_PCM_FORMAT_UNKNOWN (-1)
+
+/* NOTE: "signed" prefix must be given below since the default char is
+ *       unsigned on some architectures!
+ */
+struct pcm_format_data {
+	unsigned char width;	/* bit width */
+	unsigned char phys;	/* physical bit width */
+	signed char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
+	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
+	unsigned char silence[8];	/* silence data to fill */
+};
+
+/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
+#define INT	__force int
+
+static bool valid_format(snd_pcm_format_t format)
+{
+	return (INT)format >= 0 && (INT)format <= (INT)SNDRV_PCM_FORMAT_LAST;
+}
+
+static const struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
+	[SNDRV_PCM_FORMAT_S8] = {
+		.width = 8, .phys = 8, .le = -1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U8] = {
+		.width = 8, .phys = 8, .le = -1, .signd = 0,
+		.silence = { 0x80 },
+	},
+	[SNDRV_PCM_FORMAT_S16_LE] = {
+		.width = 16, .phys = 16, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S16_BE] = {
+		.width = 16, .phys = 16, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U16_LE] = {
+		.width = 16, .phys = 16, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x80 },
+	},
+	[SNDRV_PCM_FORMAT_U16_BE] = {
+		.width = 16, .phys = 16, .le = 0, .signd = 0,
+		.silence = { 0x80, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_S24_LE] = {
+		.width = 24, .phys = 32, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S24_BE] = {
+		.width = 24, .phys = 32, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U24_LE] = {
+		.width = 24, .phys = 32, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x00, 0x80 },
+	},
+	[SNDRV_PCM_FORMAT_U24_BE] = {
+		.width = 24, .phys = 32, .le = 0, .signd = 0,
+		.silence = { 0x00, 0x80, 0x00, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_S32_LE] = {
+		.width = 32, .phys = 32, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S32_BE] = {
+		.width = 32, .phys = 32, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U32_LE] = {
+		.width = 32, .phys = 32, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x00, 0x00, 0x80 },
+	},
+	[SNDRV_PCM_FORMAT_U32_BE] = {
+		.width = 32, .phys = 32, .le = 0, .signd = 0,
+		.silence = { 0x80, 0x00, 0x00, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_FLOAT_LE] = {
+		.width = 32, .phys = 32, .le = 1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_FLOAT_BE] = {
+		.width = 32, .phys = 32, .le = 0, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_FLOAT64_LE] = {
+		.width = 64, .phys = 64, .le = 1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_FLOAT64_BE] = {
+		.width = 64, .phys = 64, .le = 0, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
+		.width = 32, .phys = 32, .le = 1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
+		.width = 32, .phys = 32, .le = 0, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_MU_LAW] = {
+		.width = 8, .phys = 8, .le = -1, .signd = -1,
+		.silence = { 0x7f },
+	},
+	[SNDRV_PCM_FORMAT_A_LAW] = {
+		.width = 8, .phys = 8, .le = -1, .signd = -1,
+		.silence = { 0x55 },
+	},
+	[SNDRV_PCM_FORMAT_IMA_ADPCM] = {
+		.width = 4, .phys = 4, .le = -1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_G723_24] = {
+		.width = 3, .phys = 3, .le = -1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_G723_40] = {
+		.width = 5, .phys = 5, .le = -1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_DSD_U8] = {
+		.width = 8, .phys = 8, .le = 1, .signd = 0,
+		.silence = { 0x69 },
+	},
+	[SNDRV_PCM_FORMAT_DSD_U16_LE] = {
+		.width = 16, .phys = 16, .le = 1, .signd = 0,
+		.silence = { 0x69, 0x69 },
+	},
+	[SNDRV_PCM_FORMAT_DSD_U32_LE] = {
+		.width = 32, .phys = 32, .le = 1, .signd = 0,
+		.silence = { 0x69, 0x69, 0x69, 0x69 },
+	},
+	[SNDRV_PCM_FORMAT_DSD_U16_BE] = {
+		.width = 16, .phys = 16, .le = 0, .signd = 0,
+		.silence = { 0x69, 0x69 },
+	},
+	[SNDRV_PCM_FORMAT_DSD_U32_BE] = {
+		.width = 32, .phys = 32, .le = 0, .signd = 0,
+		.silence = { 0x69, 0x69, 0x69, 0x69 },
+	},
+	/* FIXME: the following two formats are not defined properly yet */
+	[SNDRV_PCM_FORMAT_MPEG] = {
+		.le = -1, .signd = -1,
+	},
+	[SNDRV_PCM_FORMAT_GSM] = {
+		.le = -1, .signd = -1,
+	},
+	[SNDRV_PCM_FORMAT_S20_LE] = {
+		.width = 20, .phys = 32, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S20_BE] = {
+		.width = 20, .phys = 32, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U20_LE] = {
+		.width = 20, .phys = 32, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x00, 0x08, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_U20_BE] = {
+		.width = 20, .phys = 32, .le = 0, .signd = 0,
+		.silence = { 0x00, 0x08, 0x00, 0x00 },
+	},
+	/* FIXME: the following format is not defined properly yet */
+	[SNDRV_PCM_FORMAT_SPECIAL] = {
+		.le = -1, .signd = -1,
+	},
+	[SNDRV_PCM_FORMAT_S24_3LE] = {
+		.width = 24, .phys = 24, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S24_3BE] = {
+		.width = 24, .phys = 24, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U24_3LE] = {
+		.width = 24, .phys = 24, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x00, 0x80 },
+	},
+	[SNDRV_PCM_FORMAT_U24_3BE] = {
+		.width = 24, .phys = 24, .le = 0, .signd = 0,
+		.silence = { 0x80, 0x00, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_S20_3LE] = {
+		.width = 20, .phys = 24, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S20_3BE] = {
+		.width = 20, .phys = 24, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U20_3LE] = {
+		.width = 20, .phys = 24, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x00, 0x08 },
+	},
+	[SNDRV_PCM_FORMAT_U20_3BE] = {
+		.width = 20, .phys = 24, .le = 0, .signd = 0,
+		.silence = { 0x08, 0x00, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_S18_3LE] = {
+		.width = 18, .phys = 24, .le = 1, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_S18_3BE] = {
+		.width = 18, .phys = 24, .le = 0, .signd = 1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_U18_3LE] = {
+		.width = 18, .phys = 24, .le = 1, .signd = 0,
+		.silence = { 0x00, 0x00, 0x02 },
+	},
+	[SNDRV_PCM_FORMAT_U18_3BE] = {
+		.width = 18, .phys = 24, .le = 0, .signd = 0,
+		.silence = { 0x02, 0x00, 0x00 },
+	},
+	[SNDRV_PCM_FORMAT_G723_24_1B] = {
+		.width = 3, .phys = 8, .le = -1, .signd = -1,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_G723_40_1B] = {
+		.width = 5, .phys = 8, .le = -1, .signd = -1,
+		.silence = {},
+	},
+};
+
+
+/**
+ * snd_pcm_format_signed - Check the PCM format is signed linear
+ * @format: the format to check
+ *
+ * Return: 1 if the given PCM format is signed linear, 0 if unsigned
+ * linear, and a negative error code for non-linear formats.
+ */
+int snd_pcm_format_signed(snd_pcm_format_t format)
+{
+	int val;
+	if (!valid_format(format))
+		return -EINVAL;
+	val = pcm_formats[(INT)format].signd;
+	if (val < 0)
+		return -EINVAL;
+	return val;
+}
+EXPORT_SYMBOL(snd_pcm_format_signed);
+
+/**
+ * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
+ * @format: the format to check
+ *
+ * Return: 1 if the given PCM format is unsigned linear, 0 if signed
+ * linear, and a negative error code for non-linear formats.
+ */
+int snd_pcm_format_unsigned(snd_pcm_format_t format)
+{
+	int val;
+
+	val = snd_pcm_format_signed(format);
+	if (val < 0)
+		return val;
+	return !val;
+}
+EXPORT_SYMBOL(snd_pcm_format_unsigned);
+
+/**
+ * snd_pcm_format_linear - Check the PCM format is linear
+ * @format: the format to check
+ *
+ * Return: 1 if the given PCM format is linear, 0 if not.
+ */
+int snd_pcm_format_linear(snd_pcm_format_t format)
+{
+	return snd_pcm_format_signed(format) >= 0;
+}
+EXPORT_SYMBOL(snd_pcm_format_linear);
+
+/**
+ * snd_pcm_format_little_endian - Check the PCM format is little-endian
+ * @format: the format to check
+ *
+ * Return: 1 if the given PCM format is little-endian, 0 if
+ * big-endian, or a negative error code if endian not specified.
+ */
+int snd_pcm_format_little_endian(snd_pcm_format_t format)
+{
+	int val;
+	if (!valid_format(format))
+		return -EINVAL;
+	val = pcm_formats[(INT)format].le;
+	if (val < 0)
+		return -EINVAL;
+	return val;
+}
+EXPORT_SYMBOL(snd_pcm_format_little_endian);
+
+/**
+ * snd_pcm_format_big_endian - Check the PCM format is big-endian
+ * @format: the format to check
+ *
+ * Return: 1 if the given PCM format is big-endian, 0 if
+ * little-endian, or a negative error code if endian not specified.
+ */
+int snd_pcm_format_big_endian(snd_pcm_format_t format)
+{
+	int val;
+
+	val = snd_pcm_format_little_endian(format);
+	if (val < 0)
+		return val;
+	return !val;
+}
+EXPORT_SYMBOL(snd_pcm_format_big_endian);
+
+/**
+ * snd_pcm_format_width - return the bit-width of the format
+ * @format: the format to check
+ *
+ * Return: The bit-width of the format, or a negative error code
+ * if unknown format.
+ */
+int snd_pcm_format_width(snd_pcm_format_t format)
+{
+	int val;
+	if (!valid_format(format))
+		return -EINVAL;
+	val = pcm_formats[(INT)format].width;
+	if (!val)
+		return -EINVAL;
+	return val;
+}
+EXPORT_SYMBOL(snd_pcm_format_width);
+
+/**
+ * snd_pcm_format_physical_width - return the physical bit-width of the format
+ * @format: the format to check
+ *
+ * Return: The physical bit-width of the format, or a negative error code
+ * if unknown format.
+ */
+int snd_pcm_format_physical_width(snd_pcm_format_t format)
+{
+	int val;
+	if (!valid_format(format))
+		return -EINVAL;
+	val = pcm_formats[(INT)format].phys;
+	if (!val)
+		return -EINVAL;
+	return val;
+}
+EXPORT_SYMBOL(snd_pcm_format_physical_width);
+
+/**
+ * snd_pcm_format_size - return the byte size of samples on the given format
+ * @format: the format to check
+ * @samples: sampling rate
+ *
+ * Return: The byte size of the given samples for the format, or a
+ * negative error code if unknown format.
+ */
+ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
+{
+	int phys_width = snd_pcm_format_physical_width(format);
+	if (phys_width < 0)
+		return -EINVAL;
+	return samples * phys_width / 8;
+}
+EXPORT_SYMBOL(snd_pcm_format_size);
+
+/**
+ * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
+ * @format: the format to check
+ *
+ * Return: The format pattern to fill or %NULL if error.
+ */
+const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
+{
+	if (!valid_format(format))
+		return NULL;
+	if (! pcm_formats[(INT)format].phys)
+		return NULL;
+	return pcm_formats[(INT)format].silence;
+}
+EXPORT_SYMBOL(snd_pcm_format_silence_64);
+
+/**
+ * snd_pcm_format_set_silence - set the silence data on the buffer
+ * @format: the PCM format
+ * @data: the buffer pointer
+ * @samples: the number of samples to set silence
+ *
+ * Sets the silence data on the buffer for the given samples.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
+{
+	int width;
+	unsigned char *dst;
+	const unsigned char *pat;
+
+	if (!valid_format(format))
+		return -EINVAL;
+	if (samples == 0)
+		return 0;
+	width = pcm_formats[(INT)format].phys; /* physical width */
+	pat = pcm_formats[(INT)format].silence;
+	if (!width || !pat)
+		return -EINVAL;
+	/* signed or 1 byte data */
+	if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
+		unsigned int bytes = samples * width / 8;
+		memset(data, *pat, bytes);
+		return 0;
+	}
+	/* non-zero samples, fill using a loop */
+	width /= 8;
+	dst = data;
+#if 0
+	while (samples--) {
+		memcpy(dst, pat, width);
+		dst += width;
+	}
+#else
+	/* a bit optimization for constant width */
+	switch (width) {
+	case 2:
+		while (samples--) {
+			memcpy(dst, pat, 2);
+			dst += 2;
+		}
+		break;
+	case 3:
+		while (samples--) {
+			memcpy(dst, pat, 3);
+			dst += 3;
+		}
+		break;
+	case 4:
+		while (samples--) {
+			memcpy(dst, pat, 4);
+			dst += 4;
+		}
+		break;
+	case 8:
+		while (samples--) {
+			memcpy(dst, pat, 8);
+			dst += 8;
+		}
+		break;
+	}
+#endif
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_format_set_silence);
+
+/**
+ * snd_pcm_hw_limit_rates - determine rate_min/rate_max fields
+ * @hw: the pcm hw instance
+ *
+ * Determines the rate_min and rate_max fields from the rates bits of
+ * the given hw.
+ *
+ * Return: Zero if successful.
+ */
+int snd_pcm_hw_limit_rates(struct snd_pcm_hardware *hw)
+{
+	int i;
+	for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
+		if (hw->rates & (1 << i)) {
+			hw->rate_min = snd_pcm_known_rates.list[i];
+			break;
+		}
+	}
+	for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
+		if (hw->rates & (1 << i)) {
+			hw->rate_max = snd_pcm_known_rates.list[i];
+			break;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_hw_limit_rates);
+
+/**
+ * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
+ * @rate: the sample rate to convert
+ *
+ * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
+ * SNDRV_PCM_RATE_KNOT for an unknown rate.
+ */
+unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
+{
+	unsigned int i;
+
+	for (i = 0; i < snd_pcm_known_rates.count; i++)
+		if (snd_pcm_known_rates.list[i] == rate)
+			return 1u << i;
+	return SNDRV_PCM_RATE_KNOT;
+}
+EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
+
+/**
+ * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
+ * @rate_bit: the rate bit to convert
+ *
+ * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
+ * or 0 for an unknown rate bit.
+ */
+unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
+{
+	unsigned int i;
+
+	for (i = 0; i < snd_pcm_known_rates.count; i++)
+		if ((1u << i) == rate_bit)
+			return snd_pcm_known_rates.list[i];
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
+
+static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
+{
+	if (rates & SNDRV_PCM_RATE_CONTINUOUS)
+		return SNDRV_PCM_RATE_CONTINUOUS;
+	else if (rates & SNDRV_PCM_RATE_KNOT)
+		return SNDRV_PCM_RATE_KNOT;
+	return rates;
+}
+
+/**
+ * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
+ * @rates_a: The first rate mask
+ * @rates_b: The second rate mask
+ *
+ * This function computes the rates that are supported by both rate masks passed
+ * to the function. It will take care of the special handling of
+ * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
+ *
+ * Return: A rate mask containing the rates that are supported by both rates_a
+ * and rates_b.
+ */
+unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
+	unsigned int rates_b)
+{
+	rates_a = snd_pcm_rate_mask_sanitize(rates_a);
+	rates_b = snd_pcm_rate_mask_sanitize(rates_b);
+
+	if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
+		return rates_b;
+	else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
+		return rates_a;
+	else if (rates_a & SNDRV_PCM_RATE_KNOT)
+		return rates_b;
+	else if (rates_b & SNDRV_PCM_RATE_KNOT)
+		return rates_a;
+	return rates_a & rates_b;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);
+
+/**
+ * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit
+ * @rate_min: the minimum sample rate
+ * @rate_max: the maximum sample rate
+ *
+ * This function has an implicit assumption: the rates in the given range have
+ * only the pre-defined rates like 44100 or 16000.
+ *
+ * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range,
+ * or SNDRV_PCM_RATE_KNOT for an unknown range.
+ */
+unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
+	unsigned int rate_max)
+{
+	unsigned int rates = 0;
+	int i;
+
+	for (i = 0; i < snd_pcm_known_rates.count; i++) {
+		if (snd_pcm_known_rates.list[i] >= rate_min
+			&& snd_pcm_known_rates.list[i] <= rate_max)
+			rates |= 1 << i;
+	}
+
+	if (!rates)
+		rates = SNDRV_PCM_RATE_KNOT;
+
+	return rates;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
new file mode 100644
index 0000000000..bd9ddf412b
--- /dev/null
+++ b/sound/core/pcm_native.c
@@ -0,0 +1,4151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/compat.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/time.h>
+#include <linux/pm_qos.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/timer.h>
+#include <sound/minors.h>
+#include <linux/uio.h>
+#include <linux/delay.h>
+
+#include "pcm_local.h"
+
+#ifdef CONFIG_SND_DEBUG
+#define CREATE_TRACE_POINTS
+#include "pcm_param_trace.h"
+#else
+#define trace_hw_mask_param_enabled()		0
+#define trace_hw_interval_param_enabled()	0
+#define trace_hw_mask_param(substream, type, index, prev, curr)
+#define trace_hw_interval_param(substream, type, index, prev, curr)
+#endif
+
+/*
+ *  Compatibility
+ */
+
+struct snd_pcm_hw_params_old {
+	unsigned int flags;
+	unsigned int masks[SNDRV_PCM_HW_PARAM_SUBFORMAT -
+			   SNDRV_PCM_HW_PARAM_ACCESS + 1];
+	struct snd_interval intervals[SNDRV_PCM_HW_PARAM_TICK_TIME -
+					SNDRV_PCM_HW_PARAM_SAMPLE_BITS + 1];
+	unsigned int rmask;
+	unsigned int cmask;
+	unsigned int info;
+	unsigned int msbits;
+	unsigned int rate_num;
+	unsigned int rate_den;
+	snd_pcm_uframes_t fifo_size;
+	unsigned char reserved[64];
+};
+
+#ifdef CONFIG_SND_SUPPORT_OLD_API
+#define SNDRV_PCM_IOCTL_HW_REFINE_OLD _IOWR('A', 0x10, struct snd_pcm_hw_params_old)
+#define SNDRV_PCM_IOCTL_HW_PARAMS_OLD _IOWR('A', 0x11, struct snd_pcm_hw_params_old)
+
+static int snd_pcm_hw_refine_old_user(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params_old __user * _oparams);
+static int snd_pcm_hw_params_old_user(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params_old __user * _oparams);
+#endif
+static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream);
+
+/*
+ *
+ */
+
+static DECLARE_RWSEM(snd_pcm_link_rwsem);
+
+void snd_pcm_group_init(struct snd_pcm_group *group)
+{
+	spin_lock_init(&group->lock);
+	mutex_init(&group->mutex);
+	INIT_LIST_HEAD(&group->substreams);
+	refcount_set(&group->refs, 1);
+}
+
+/* define group lock helpers */
+#define DEFINE_PCM_GROUP_LOCK(action, mutex_action) \
+static void snd_pcm_group_ ## action(struct snd_pcm_group *group, bool nonatomic) \
+{ \
+	if (nonatomic) \
+		mutex_ ## mutex_action(&group->mutex); \
+	else \
+		spin_ ## action(&group->lock); \
+}
+
+DEFINE_PCM_GROUP_LOCK(lock, lock);
+DEFINE_PCM_GROUP_LOCK(unlock, unlock);
+DEFINE_PCM_GROUP_LOCK(lock_irq, lock);
+DEFINE_PCM_GROUP_LOCK(unlock_irq, unlock);
+
+/**
+ * snd_pcm_stream_lock - Lock the PCM stream
+ * @substream: PCM substream
+ *
+ * This locks the PCM stream's spinlock or mutex depending on the nonatomic
+ * flag of the given substream.  This also takes the global link rw lock
+ * (or rw sem), too, for avoiding the race with linked streams.
+ */
+void snd_pcm_stream_lock(struct snd_pcm_substream *substream)
+{
+	snd_pcm_group_lock(&substream->self_group, substream->pcm->nonatomic);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);
+
+/**
+ * snd_pcm_stream_unlock - Unlock the PCM stream
+ * @substream: PCM substream
+ *
+ * This unlocks the PCM stream that has been locked via snd_pcm_stream_lock().
+ */
+void snd_pcm_stream_unlock(struct snd_pcm_substream *substream)
+{
+	snd_pcm_group_unlock(&substream->self_group, substream->pcm->nonatomic);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);
+
+/**
+ * snd_pcm_stream_lock_irq - Lock the PCM stream
+ * @substream: PCM substream
+ *
+ * This locks the PCM stream like snd_pcm_stream_lock() and disables the local
+ * IRQ (only when nonatomic is false).  In nonatomic case, this is identical
+ * as snd_pcm_stream_lock().
+ */
+void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream)
+{
+	snd_pcm_group_lock_irq(&substream->self_group,
+			       substream->pcm->nonatomic);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
+
+static void snd_pcm_stream_lock_nested(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_group *group = &substream->self_group;
+
+	if (substream->pcm->nonatomic)
+		mutex_lock_nested(&group->mutex, SINGLE_DEPTH_NESTING);
+	else
+		spin_lock_nested(&group->lock, SINGLE_DEPTH_NESTING);
+}
+
+/**
+ * snd_pcm_stream_unlock_irq - Unlock the PCM stream
+ * @substream: PCM substream
+ *
+ * This is a counter-part of snd_pcm_stream_lock_irq().
+ */
+void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream)
+{
+	snd_pcm_group_unlock_irq(&substream->self_group,
+				 substream->pcm->nonatomic);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq);
+
+unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream)
+{
+	unsigned long flags = 0;
+	if (substream->pcm->nonatomic)
+		mutex_lock(&substream->self_group.mutex);
+	else
+		spin_lock_irqsave(&substream->self_group.lock, flags);
+	return flags;
+}
+EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);
+
+unsigned long _snd_pcm_stream_lock_irqsave_nested(struct snd_pcm_substream *substream)
+{
+	unsigned long flags = 0;
+	if (substream->pcm->nonatomic)
+		mutex_lock_nested(&substream->self_group.mutex,
+				  SINGLE_DEPTH_NESTING);
+	else
+		spin_lock_irqsave_nested(&substream->self_group.lock, flags,
+					 SINGLE_DEPTH_NESTING);
+	return flags;
+}
+EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave_nested);
+
+/**
+ * snd_pcm_stream_unlock_irqrestore - Unlock the PCM stream
+ * @substream: PCM substream
+ * @flags: irq flags
+ *
+ * This is a counter-part of snd_pcm_stream_lock_irqsave().
+ */
+void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
+				      unsigned long flags)
+{
+	if (substream->pcm->nonatomic)
+		mutex_unlock(&substream->self_group.mutex);
+	else
+		spin_unlock_irqrestore(&substream->self_group.lock, flags);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore);
+
+/* Run PCM ioctl ops */
+static int snd_pcm_ops_ioctl(struct snd_pcm_substream *substream,
+			     unsigned cmd, void *arg)
+{
+	if (substream->ops->ioctl)
+		return substream->ops->ioctl(substream, cmd, arg);
+	else
+		return snd_pcm_lib_ioctl(substream, cmd, arg);
+}
+
+int snd_pcm_info(struct snd_pcm_substream *substream, struct snd_pcm_info *info)
+{
+	struct snd_pcm *pcm = substream->pcm;
+	struct snd_pcm_str *pstr = substream->pstr;
+
+	memset(info, 0, sizeof(*info));
+	info->card = pcm->card->number;
+	info->device = pcm->device;
+	info->stream = substream->stream;
+	info->subdevice = substream->number;
+	strscpy(info->id, pcm->id, sizeof(info->id));
+	strscpy(info->name, pcm->name, sizeof(info->name));
+	info->dev_class = pcm->dev_class;
+	info->dev_subclass = pcm->dev_subclass;
+	info->subdevices_count = pstr->substream_count;
+	info->subdevices_avail = pstr->substream_count - pstr->substream_opened;
+	strscpy(info->subname, substream->name, sizeof(info->subname));
+
+	return 0;
+}
+
+int snd_pcm_info_user(struct snd_pcm_substream *substream,
+		      struct snd_pcm_info __user * _info)
+{
+	struct snd_pcm_info *info;
+	int err;
+
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (! info)
+		return -ENOMEM;
+	err = snd_pcm_info(substream, info);
+	if (err >= 0) {
+		if (copy_to_user(_info, info, sizeof(*info)))
+			err = -EFAULT;
+	}
+	kfree(info);
+	return err;
+}
+
+/* macro for simplified cast */
+#define PARAM_MASK_BIT(b)	(1U << (__force int)(b))
+
+static bool hw_support_mmap(struct snd_pcm_substream *substream)
+{
+	struct snd_dma_buffer *dmabuf;
+
+	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP))
+		return false;
+
+	if (substream->ops->mmap || substream->ops->page)
+		return true;
+
+	dmabuf = snd_pcm_get_dma_buf(substream);
+	if (!dmabuf)
+		dmabuf = &substream->dma_buffer;
+	switch (dmabuf->dev.type) {
+	case SNDRV_DMA_TYPE_UNKNOWN:
+		/* we can't know the device, so just assume that the driver does
+		 * everything right
+		 */
+		return true;
+	case SNDRV_DMA_TYPE_CONTINUOUS:
+	case SNDRV_DMA_TYPE_VMALLOC:
+		return true;
+	default:
+		return dma_can_mmap(dmabuf->dev.dev);
+	}
+}
+
+static int constrain_mask_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_hw_constraints *constrs =
+					&substream->runtime->hw_constraints;
+	struct snd_mask *m;
+	unsigned int k;
+	struct snd_mask old_mask __maybe_unused;
+	int changed;
+
+	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) {
+		m = hw_param_mask(params, k);
+		if (snd_mask_empty(m))
+			return -EINVAL;
+
+		/* This parameter is not requested to change by a caller. */
+		if (!(params->rmask & PARAM_MASK_BIT(k)))
+			continue;
+
+		if (trace_hw_mask_param_enabled())
+			old_mask = *m;
+
+		changed = snd_mask_refine(m, constrs_mask(constrs, k));
+		if (changed < 0)
+			return changed;
+		if (changed == 0)
+			continue;
+
+		/* Set corresponding flag so that the caller gets it. */
+		trace_hw_mask_param(substream, k, 0, &old_mask, m);
+		params->cmask |= PARAM_MASK_BIT(k);
+	}
+
+	return 0;
+}
+
+static int constrain_interval_params(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_hw_constraints *constrs =
+					&substream->runtime->hw_constraints;
+	struct snd_interval *i;
+	unsigned int k;
+	struct snd_interval old_interval __maybe_unused;
+	int changed;
+
+	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
+		i = hw_param_interval(params, k);
+		if (snd_interval_empty(i))
+			return -EINVAL;
+
+		/* This parameter is not requested to change by a caller. */
+		if (!(params->rmask & PARAM_MASK_BIT(k)))
+			continue;
+
+		if (trace_hw_interval_param_enabled())
+			old_interval = *i;
+
+		changed = snd_interval_refine(i, constrs_interval(constrs, k));
+		if (changed < 0)
+			return changed;
+		if (changed == 0)
+			continue;
+
+		/* Set corresponding flag so that the caller gets it. */
+		trace_hw_interval_param(substream, k, 0, &old_interval, i);
+		params->cmask |= PARAM_MASK_BIT(k);
+	}
+
+	return 0;
+}
+
+static int constrain_params_by_rules(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_hw_constraints *constrs =
+					&substream->runtime->hw_constraints;
+	unsigned int k;
+	unsigned int *rstamps;
+	unsigned int vstamps[SNDRV_PCM_HW_PARAM_LAST_INTERVAL + 1];
+	unsigned int stamp;
+	struct snd_pcm_hw_rule *r;
+	unsigned int d;
+	struct snd_mask old_mask __maybe_unused;
+	struct snd_interval old_interval __maybe_unused;
+	bool again;
+	int changed, err = 0;
+
+	/*
+	 * Each application of rule has own sequence number.
+	 *
+	 * Each member of 'rstamps' array represents the sequence number of
+	 * recent application of corresponding rule.
+	 */
+	rstamps = kcalloc(constrs->rules_num, sizeof(unsigned int), GFP_KERNEL);
+	if (!rstamps)
+		return -ENOMEM;
+
+	/*
+	 * Each member of 'vstamps' array represents the sequence number of
+	 * recent application of rule in which corresponding parameters were
+	 * changed.
+	 *
+	 * In initial state, elements corresponding to parameters requested by
+	 * a caller is 1. For unrequested parameters, corresponding members
+	 * have 0 so that the parameters are never changed anymore.
+	 */
+	for (k = 0; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
+		vstamps[k] = (params->rmask & PARAM_MASK_BIT(k)) ? 1 : 0;
+
+	/* Due to the above design, actual sequence number starts at 2. */
+	stamp = 2;
+retry:
+	/* Apply all rules in order. */
+	again = false;
+	for (k = 0; k < constrs->rules_num; k++) {
+		r = &constrs->rules[k];
+
+		/*
+		 * Check condition bits of this rule. When the rule has
+		 * some condition bits, parameter without the bits is
+		 * never processed. SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP
+		 * is an example of the condition bits.
+		 */
+		if (r->cond && !(r->cond & params->flags))
+			continue;
+
+		/*
+		 * The 'deps' array includes maximum four dependencies
+		 * to SNDRV_PCM_HW_PARAM_XXXs for this rule. The fifth
+		 * member of this array is a sentinel and should be
+		 * negative value.
+		 *
+		 * This rule should be processed in this time when dependent
+		 * parameters were changed at former applications of the other
+		 * rules.
+		 */
+		for (d = 0; r->deps[d] >= 0; d++) {
+			if (vstamps[r->deps[d]] > rstamps[k])
+				break;
+		}
+		if (r->deps[d] < 0)
+			continue;
+
+		if (trace_hw_mask_param_enabled()) {
+			if (hw_is_mask(r->var))
+				old_mask = *hw_param_mask(params, r->var);
+		}
+		if (trace_hw_interval_param_enabled()) {
+			if (hw_is_interval(r->var))
+				old_interval = *hw_param_interval(params, r->var);
+		}
+
+		changed = r->func(params, r);
+		if (changed < 0) {
+			err = changed;
+			goto out;
+		}
+
+		/*
+		 * When the parameter is changed, notify it to the caller
+		 * by corresponding returned bit, then preparing for next
+		 * iteration.
+		 */
+		if (changed && r->var >= 0) {
+			if (hw_is_mask(r->var)) {
+				trace_hw_mask_param(substream, r->var,
+					k + 1, &old_mask,
+					hw_param_mask(params, r->var));
+			}
+			if (hw_is_interval(r->var)) {
+				trace_hw_interval_param(substream, r->var,
+					k + 1, &old_interval,
+					hw_param_interval(params, r->var));
+			}
+
+			params->cmask |= PARAM_MASK_BIT(r->var);
+			vstamps[r->var] = stamp;
+			again = true;
+		}
+
+		rstamps[k] = stamp++;
+	}
+
+	/* Iterate to evaluate all rules till no parameters are changed. */
+	if (again)
+		goto retry;
+
+ out:
+	kfree(rstamps);
+	return err;
+}
+
+static int fixup_unreferenced_params(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params)
+{
+	const struct snd_interval *i;
+	const struct snd_mask *m;
+	int err;
+
+	if (!params->msbits) {
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
+		if (snd_interval_single(i))
+			params->msbits = snd_interval_value(i);
+	}
+
+	if (!params->rate_den) {
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
+		if (snd_interval_single(i)) {
+			params->rate_num = snd_interval_value(i);
+			params->rate_den = 1;
+		}
+	}
+
+	if (!params->fifo_size) {
+		m = hw_param_mask_c(params, SNDRV_PCM_HW_PARAM_FORMAT);
+		i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+		if (snd_mask_single(m) && snd_interval_single(i)) {
+			err = snd_pcm_ops_ioctl(substream,
+						SNDRV_PCM_IOCTL1_FIFO_SIZE,
+						params);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	if (!params->info) {
+		params->info = substream->runtime->hw.info;
+		params->info &= ~(SNDRV_PCM_INFO_FIFO_IN_FRAMES |
+				  SNDRV_PCM_INFO_DRAIN_TRIGGER);
+		if (!hw_support_mmap(substream))
+			params->info &= ~(SNDRV_PCM_INFO_MMAP |
+					  SNDRV_PCM_INFO_MMAP_VALID);
+	}
+
+	return 0;
+}
+
+int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
+		      struct snd_pcm_hw_params *params)
+{
+	int err;
+
+	params->info = 0;
+	params->fifo_size = 0;
+	if (params->rmask & PARAM_MASK_BIT(SNDRV_PCM_HW_PARAM_SAMPLE_BITS))
+		params->msbits = 0;
+	if (params->rmask & PARAM_MASK_BIT(SNDRV_PCM_HW_PARAM_RATE)) {
+		params->rate_num = 0;
+		params->rate_den = 0;
+	}
+
+	err = constrain_mask_params(substream, params);
+	if (err < 0)
+		return err;
+
+	err = constrain_interval_params(substream, params);
+	if (err < 0)
+		return err;
+
+	err = constrain_params_by_rules(substream, params);
+	if (err < 0)
+		return err;
+
+	params->rmask = 0;
+
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_hw_refine);
+
+static int snd_pcm_hw_refine_user(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params __user * _params)
+{
+	struct snd_pcm_hw_params *params;
+	int err;
+
+	params = memdup_user(_params, sizeof(*params));
+	if (IS_ERR(params))
+		return PTR_ERR(params);
+
+	err = snd_pcm_hw_refine(substream, params);
+	if (err < 0)
+		goto end;
+
+	err = fixup_unreferenced_params(substream, params);
+	if (err < 0)
+		goto end;
+
+	if (copy_to_user(_params, params, sizeof(*params)))
+		err = -EFAULT;
+end:
+	kfree(params);
+	return err;
+}
+
+static int period_to_usecs(struct snd_pcm_runtime *runtime)
+{
+	int usecs;
+
+	if (! runtime->rate)
+		return -1; /* invalid */
+
+	/* take 75% of period time as the deadline */
+	usecs = (750000 / runtime->rate) * runtime->period_size;
+	usecs += ((750000 % runtime->rate) * runtime->period_size) /
+		runtime->rate;
+
+	return usecs;
+}
+
+static void snd_pcm_set_state(struct snd_pcm_substream *substream,
+			      snd_pcm_state_t state)
+{
+	snd_pcm_stream_lock_irq(substream);
+	if (substream->runtime->state != SNDRV_PCM_STATE_DISCONNECTED)
+		__snd_pcm_set_state(substream->runtime, state);
+	snd_pcm_stream_unlock_irq(substream);
+}
+
+static inline void snd_pcm_timer_notify(struct snd_pcm_substream *substream,
+					int event)
+{
+#ifdef CONFIG_SND_PCM_TIMER
+	if (substream->timer)
+		snd_timer_notify(substream->timer, event,
+					&substream->runtime->trigger_tstamp);
+#endif
+}
+
+void snd_pcm_sync_stop(struct snd_pcm_substream *substream, bool sync_irq)
+{
+	if (substream->runtime && substream->runtime->stop_operating) {
+		substream->runtime->stop_operating = false;
+		if (substream->ops && substream->ops->sync_stop)
+			substream->ops->sync_stop(substream);
+		else if (sync_irq && substream->pcm->card->sync_irq > 0)
+			synchronize_irq(substream->pcm->card->sync_irq);
+	}
+}
+
+/**
+ * snd_pcm_hw_params_choose - choose a configuration defined by @params
+ * @pcm: PCM instance
+ * @params: the hw_params instance
+ *
+ * Choose one configuration from configuration space defined by @params.
+ * The configuration chosen is that obtained fixing in this order:
+ * first access, first format, first subformat, min channels,
+ * min rate, min period time, max buffer size, min tick time
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+static int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
+				    struct snd_pcm_hw_params *params)
+{
+	static const int vars[] = {
+		SNDRV_PCM_HW_PARAM_ACCESS,
+		SNDRV_PCM_HW_PARAM_FORMAT,
+		SNDRV_PCM_HW_PARAM_SUBFORMAT,
+		SNDRV_PCM_HW_PARAM_CHANNELS,
+		SNDRV_PCM_HW_PARAM_RATE,
+		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
+		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+		SNDRV_PCM_HW_PARAM_TICK_TIME,
+		-1
+	};
+	const int *v;
+	struct snd_mask old_mask __maybe_unused;
+	struct snd_interval old_interval __maybe_unused;
+	int changed;
+
+	for (v = vars; *v != -1; v++) {
+		/* Keep old parameter to trace. */
+		if (trace_hw_mask_param_enabled()) {
+			if (hw_is_mask(*v))
+				old_mask = *hw_param_mask(params, *v);
+		}
+		if (trace_hw_interval_param_enabled()) {
+			if (hw_is_interval(*v))
+				old_interval = *hw_param_interval(params, *v);
+		}
+		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
+			changed = snd_pcm_hw_param_first(pcm, params, *v, NULL);
+		else
+			changed = snd_pcm_hw_param_last(pcm, params, *v, NULL);
+		if (changed < 0)
+			return changed;
+		if (changed == 0)
+			continue;
+
+		/* Trace the changed parameter. */
+		if (hw_is_mask(*v)) {
+			trace_hw_mask_param(pcm, *v, 0, &old_mask,
+					    hw_param_mask(params, *v));
+		}
+		if (hw_is_interval(*v)) {
+			trace_hw_interval_param(pcm, *v, 0, &old_interval,
+						hw_param_interval(params, *v));
+		}
+	}
+
+	return 0;
+}
+
+/* acquire buffer_mutex; if it's in r/w operation, return -EBUSY, otherwise
+ * block the further r/w operations
+ */
+static int snd_pcm_buffer_access_lock(struct snd_pcm_runtime *runtime)
+{
+	if (!atomic_dec_unless_positive(&runtime->buffer_accessing))
+		return -EBUSY;
+	mutex_lock(&runtime->buffer_mutex);
+	return 0; /* keep buffer_mutex, unlocked by below */
+}
+
+/* release buffer_mutex and clear r/w access flag */
+static void snd_pcm_buffer_access_unlock(struct snd_pcm_runtime *runtime)
+{
+	mutex_unlock(&runtime->buffer_mutex);
+	atomic_inc(&runtime->buffer_accessing);
+}
+
+#if IS_ENABLED(CONFIG_SND_PCM_OSS)
+#define is_oss_stream(substream)	((substream)->oss.oss)
+#else
+#define is_oss_stream(substream)	false
+#endif
+
+static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
+			     struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_runtime *runtime;
+	int err, usecs;
+	unsigned int bits;
+	snd_pcm_uframes_t frames;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	err = snd_pcm_buffer_access_lock(runtime);
+	if (err < 0)
+		return err;
+	snd_pcm_stream_lock_irq(substream);
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_PREPARED:
+		if (!is_oss_stream(substream) &&
+		    atomic_read(&substream->mmap_count))
+			err = -EBADFD;
+		break;
+	default:
+		err = -EBADFD;
+		break;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+	if (err)
+		goto unlock;
+
+	snd_pcm_sync_stop(substream, true);
+
+	params->rmask = ~0U;
+	err = snd_pcm_hw_refine(substream, params);
+	if (err < 0)
+		goto _error;
+
+	err = snd_pcm_hw_params_choose(substream, params);
+	if (err < 0)
+		goto _error;
+
+	err = fixup_unreferenced_params(substream, params);
+	if (err < 0)
+		goto _error;
+
+	if (substream->managed_buffer_alloc) {
+		err = snd_pcm_lib_malloc_pages(substream,
+					       params_buffer_bytes(params));
+		if (err < 0)
+			goto _error;
+		runtime->buffer_changed = err > 0;
+	}
+
+	if (substream->ops->hw_params != NULL) {
+		err = substream->ops->hw_params(substream, params);
+		if (err < 0)
+			goto _error;
+	}
+
+	runtime->access = params_access(params);
+	runtime->format = params_format(params);
+	runtime->subformat = params_subformat(params);
+	runtime->channels = params_channels(params);
+	runtime->rate = params_rate(params);
+	runtime->period_size = params_period_size(params);
+	runtime->periods = params_periods(params);
+	runtime->buffer_size = params_buffer_size(params);
+	runtime->info = params->info;
+	runtime->rate_num = params->rate_num;
+	runtime->rate_den = params->rate_den;
+	runtime->no_period_wakeup =
+			(params->info & SNDRV_PCM_INFO_NO_PERIOD_WAKEUP) &&
+			(params->flags & SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP);
+
+	bits = snd_pcm_format_physical_width(runtime->format);
+	runtime->sample_bits = bits;
+	bits *= runtime->channels;
+	runtime->frame_bits = bits;
+	frames = 1;
+	while (bits % 8 != 0) {
+		bits *= 2;
+		frames *= 2;
+	}
+	runtime->byte_align = bits / 8;
+	runtime->min_align = frames;
+
+	/* Default sw params */
+	runtime->tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
+	runtime->period_step = 1;
+	runtime->control->avail_min = runtime->period_size;
+	runtime->start_threshold = 1;
+	runtime->stop_threshold = runtime->buffer_size;
+	runtime->silence_threshold = 0;
+	runtime->silence_size = 0;
+	runtime->boundary = runtime->buffer_size;
+	while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size)
+		runtime->boundary *= 2;
+
+	/* clear the buffer for avoiding possible kernel info leaks */
+	if (runtime->dma_area && !substream->ops->copy) {
+		size_t size = runtime->dma_bytes;
+
+		if (runtime->info & SNDRV_PCM_INFO_MMAP)
+			size = PAGE_ALIGN(size);
+		memset(runtime->dma_area, 0, size);
+	}
+
+	snd_pcm_timer_resolution_change(substream);
+	snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);
+
+	if (cpu_latency_qos_request_active(&substream->latency_pm_qos_req))
+		cpu_latency_qos_remove_request(&substream->latency_pm_qos_req);
+	usecs = period_to_usecs(runtime);
+	if (usecs >= 0)
+		cpu_latency_qos_add_request(&substream->latency_pm_qos_req,
+					    usecs);
+	err = 0;
+ _error:
+	if (err) {
+		/* hardware might be unusable from this time,
+		 * so we force application to retry to set
+		 * the correct hardware parameter settings
+		 */
+		snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
+		if (substream->ops->hw_free != NULL)
+			substream->ops->hw_free(substream);
+		if (substream->managed_buffer_alloc)
+			snd_pcm_lib_free_pages(substream);
+	}
+ unlock:
+	snd_pcm_buffer_access_unlock(runtime);
+	return err;
+}
+
+static int snd_pcm_hw_params_user(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params __user * _params)
+{
+	struct snd_pcm_hw_params *params;
+	int err;
+
+	params = memdup_user(_params, sizeof(*params));
+	if (IS_ERR(params))
+		return PTR_ERR(params);
+
+	err = snd_pcm_hw_params(substream, params);
+	if (err < 0)
+		goto end;
+
+	if (copy_to_user(_params, params, sizeof(*params)))
+		err = -EFAULT;
+end:
+	kfree(params);
+	return err;
+}
+
+static int do_hw_free(struct snd_pcm_substream *substream)
+{
+	int result = 0;
+
+	snd_pcm_sync_stop(substream, true);
+	if (substream->ops->hw_free)
+		result = substream->ops->hw_free(substream);
+	if (substream->managed_buffer_alloc)
+		snd_pcm_lib_free_pages(substream);
+	return result;
+}
+
+static int snd_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+	int result = 0;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	result = snd_pcm_buffer_access_lock(runtime);
+	if (result < 0)
+		return result;
+	snd_pcm_stream_lock_irq(substream);
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_PREPARED:
+		if (atomic_read(&substream->mmap_count))
+			result = -EBADFD;
+		break;
+	default:
+		result = -EBADFD;
+		break;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+	if (result)
+		goto unlock;
+	result = do_hw_free(substream);
+	snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
+	cpu_latency_qos_remove_request(&substream->latency_pm_qos_req);
+ unlock:
+	snd_pcm_buffer_access_unlock(runtime);
+	return result;
+}
+
+static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
+			     struct snd_pcm_sw_params *params)
+{
+	struct snd_pcm_runtime *runtime;
+	int err;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	snd_pcm_stream_lock_irq(substream);
+	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
+		snd_pcm_stream_unlock_irq(substream);
+		return -EBADFD;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+
+	if (params->tstamp_mode < 0 ||
+	    params->tstamp_mode > SNDRV_PCM_TSTAMP_LAST)
+		return -EINVAL;
+	if (params->proto >= SNDRV_PROTOCOL_VERSION(2, 0, 12) &&
+	    params->tstamp_type > SNDRV_PCM_TSTAMP_TYPE_LAST)
+		return -EINVAL;
+	if (params->avail_min == 0)
+		return -EINVAL;
+	if (params->silence_size >= runtime->boundary) {
+		if (params->silence_threshold != 0)
+			return -EINVAL;
+	} else {
+		if (params->silence_size > params->silence_threshold)
+			return -EINVAL;
+		if (params->silence_threshold > runtime->buffer_size)
+			return -EINVAL;
+	}
+	err = 0;
+	snd_pcm_stream_lock_irq(substream);
+	runtime->tstamp_mode = params->tstamp_mode;
+	if (params->proto >= SNDRV_PROTOCOL_VERSION(2, 0, 12))
+		runtime->tstamp_type = params->tstamp_type;
+	runtime->period_step = params->period_step;
+	runtime->control->avail_min = params->avail_min;
+	runtime->start_threshold = params->start_threshold;
+	runtime->stop_threshold = params->stop_threshold;
+	runtime->silence_threshold = params->silence_threshold;
+	runtime->silence_size = params->silence_size;
+        params->boundary = runtime->boundary;
+	if (snd_pcm_running(substream)) {
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+		    runtime->silence_size > 0)
+			snd_pcm_playback_silence(substream, ULONG_MAX);
+		err = snd_pcm_update_state(substream, runtime);
+	}
+	snd_pcm_stream_unlock_irq(substream);
+	return err;
+}
+
+static int snd_pcm_sw_params_user(struct snd_pcm_substream *substream,
+				  struct snd_pcm_sw_params __user * _params)
+{
+	struct snd_pcm_sw_params params;
+	int err;
+	if (copy_from_user(&params, _params, sizeof(params)))
+		return -EFAULT;
+	err = snd_pcm_sw_params(substream, &params);
+	if (copy_to_user(_params, &params, sizeof(params)))
+		return -EFAULT;
+	return err;
+}
+
+static inline snd_pcm_uframes_t
+snd_pcm_calc_delay(struct snd_pcm_substream *substream)
+{
+	snd_pcm_uframes_t delay;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		delay = snd_pcm_playback_hw_avail(substream->runtime);
+	else
+		delay = snd_pcm_capture_avail(substream->runtime);
+	return delay + substream->runtime->delay;
+}
+
+int snd_pcm_status64(struct snd_pcm_substream *substream,
+		     struct snd_pcm_status64 *status)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	snd_pcm_stream_lock_irq(substream);
+
+	snd_pcm_unpack_audio_tstamp_config(status->audio_tstamp_data,
+					&runtime->audio_tstamp_config);
+
+	/* backwards compatible behavior */
+	if (runtime->audio_tstamp_config.type_requested ==
+		SNDRV_PCM_AUDIO_TSTAMP_TYPE_COMPAT) {
+		if (runtime->hw.info & SNDRV_PCM_INFO_HAS_WALL_CLOCK)
+			runtime->audio_tstamp_config.type_requested =
+				SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK;
+		else
+			runtime->audio_tstamp_config.type_requested =
+				SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT;
+		runtime->audio_tstamp_report.valid = 0;
+	} else
+		runtime->audio_tstamp_report.valid = 1;
+
+	status->state = runtime->state;
+	status->suspended_state = runtime->suspended_state;
+	if (status->state == SNDRV_PCM_STATE_OPEN)
+		goto _end;
+	status->trigger_tstamp_sec = runtime->trigger_tstamp.tv_sec;
+	status->trigger_tstamp_nsec = runtime->trigger_tstamp.tv_nsec;
+	if (snd_pcm_running(substream)) {
+		snd_pcm_update_hw_ptr(substream);
+		if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
+			status->tstamp_sec = runtime->status->tstamp.tv_sec;
+			status->tstamp_nsec =
+				runtime->status->tstamp.tv_nsec;
+			status->driver_tstamp_sec =
+				runtime->driver_tstamp.tv_sec;
+			status->driver_tstamp_nsec =
+				runtime->driver_tstamp.tv_nsec;
+			status->audio_tstamp_sec =
+				runtime->status->audio_tstamp.tv_sec;
+			status->audio_tstamp_nsec =
+				runtime->status->audio_tstamp.tv_nsec;
+			if (runtime->audio_tstamp_report.valid == 1)
+				/* backwards compatibility, no report provided in COMPAT mode */
+				snd_pcm_pack_audio_tstamp_report(&status->audio_tstamp_data,
+								&status->audio_tstamp_accuracy,
+								&runtime->audio_tstamp_report);
+
+			goto _tstamp_end;
+		}
+	} else {
+		/* get tstamp only in fallback mode and only if enabled */
+		if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
+			struct timespec64 tstamp;
+
+			snd_pcm_gettime(runtime, &tstamp);
+			status->tstamp_sec = tstamp.tv_sec;
+			status->tstamp_nsec = tstamp.tv_nsec;
+		}
+	}
+ _tstamp_end:
+	status->appl_ptr = runtime->control->appl_ptr;
+	status->hw_ptr = runtime->status->hw_ptr;
+	status->avail = snd_pcm_avail(substream);
+	status->delay = snd_pcm_running(substream) ?
+		snd_pcm_calc_delay(substream) : 0;
+	status->avail_max = runtime->avail_max;
+	status->overrange = runtime->overrange;
+	runtime->avail_max = 0;
+	runtime->overrange = 0;
+ _end:
+ 	snd_pcm_stream_unlock_irq(substream);
+	return 0;
+}
+
+static int snd_pcm_status_user64(struct snd_pcm_substream *substream,
+				 struct snd_pcm_status64 __user * _status,
+				 bool ext)
+{
+	struct snd_pcm_status64 status;
+	int res;
+
+	memset(&status, 0, sizeof(status));
+	/*
+	 * with extension, parameters are read/write,
+	 * get audio_tstamp_data from user,
+	 * ignore rest of status structure
+	 */
+	if (ext && get_user(status.audio_tstamp_data,
+				(u32 __user *)(&_status->audio_tstamp_data)))
+		return -EFAULT;
+	res = snd_pcm_status64(substream, &status);
+	if (res < 0)
+		return res;
+	if (copy_to_user(_status, &status, sizeof(status)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_pcm_status_user32(struct snd_pcm_substream *substream,
+				 struct snd_pcm_status32 __user * _status,
+				 bool ext)
+{
+	struct snd_pcm_status64 status64;
+	struct snd_pcm_status32 status32;
+	int res;
+
+	memset(&status64, 0, sizeof(status64));
+	memset(&status32, 0, sizeof(status32));
+	/*
+	 * with extension, parameters are read/write,
+	 * get audio_tstamp_data from user,
+	 * ignore rest of status structure
+	 */
+	if (ext && get_user(status64.audio_tstamp_data,
+			    (u32 __user *)(&_status->audio_tstamp_data)))
+		return -EFAULT;
+	res = snd_pcm_status64(substream, &status64);
+	if (res < 0)
+		return res;
+
+	status32 = (struct snd_pcm_status32) {
+		.state = status64.state,
+		.trigger_tstamp_sec = status64.trigger_tstamp_sec,
+		.trigger_tstamp_nsec = status64.trigger_tstamp_nsec,
+		.tstamp_sec = status64.tstamp_sec,
+		.tstamp_nsec = status64.tstamp_nsec,
+		.appl_ptr = status64.appl_ptr,
+		.hw_ptr = status64.hw_ptr,
+		.delay = status64.delay,
+		.avail = status64.avail,
+		.avail_max = status64.avail_max,
+		.overrange = status64.overrange,
+		.suspended_state = status64.suspended_state,
+		.audio_tstamp_data = status64.audio_tstamp_data,
+		.audio_tstamp_sec = status64.audio_tstamp_sec,
+		.audio_tstamp_nsec = status64.audio_tstamp_nsec,
+		.driver_tstamp_sec = status64.audio_tstamp_sec,
+		.driver_tstamp_nsec = status64.audio_tstamp_nsec,
+		.audio_tstamp_accuracy = status64.audio_tstamp_accuracy,
+	};
+
+	if (copy_to_user(_status, &status32, sizeof(status32)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int snd_pcm_channel_info(struct snd_pcm_substream *substream,
+				struct snd_pcm_channel_info * info)
+{
+	struct snd_pcm_runtime *runtime;
+	unsigned int channel;
+	
+	channel = info->channel;
+	runtime = substream->runtime;
+	snd_pcm_stream_lock_irq(substream);
+	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
+		snd_pcm_stream_unlock_irq(substream);
+		return -EBADFD;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+	if (channel >= runtime->channels)
+		return -EINVAL;
+	memset(info, 0, sizeof(*info));
+	info->channel = channel;
+	return snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_CHANNEL_INFO, info);
+}
+
+static int snd_pcm_channel_info_user(struct snd_pcm_substream *substream,
+				     struct snd_pcm_channel_info __user * _info)
+{
+	struct snd_pcm_channel_info info;
+	int res;
+	
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	res = snd_pcm_channel_info(substream, &info);
+	if (res < 0)
+		return res;
+	if (copy_to_user(_info, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static void snd_pcm_trigger_tstamp(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (runtime->trigger_master == NULL)
+		return;
+	if (runtime->trigger_master == substream) {
+		if (!runtime->trigger_tstamp_latched)
+			snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
+	} else {
+		snd_pcm_trigger_tstamp(runtime->trigger_master);
+		runtime->trigger_tstamp = runtime->trigger_master->runtime->trigger_tstamp;
+	}
+	runtime->trigger_master = NULL;
+}
+
+#define ACTION_ARG_IGNORE	(__force snd_pcm_state_t)0
+
+struct action_ops {
+	int (*pre_action)(struct snd_pcm_substream *substream,
+			  snd_pcm_state_t state);
+	int (*do_action)(struct snd_pcm_substream *substream,
+			 snd_pcm_state_t state);
+	void (*undo_action)(struct snd_pcm_substream *substream,
+			    snd_pcm_state_t state);
+	void (*post_action)(struct snd_pcm_substream *substream,
+			    snd_pcm_state_t state);
+};
+
+/*
+ *  this functions is core for handling of linked stream
+ *  Note: the stream state might be changed also on failure
+ *  Note2: call with calling stream lock + link lock
+ */
+static int snd_pcm_action_group(const struct action_ops *ops,
+				struct snd_pcm_substream *substream,
+				snd_pcm_state_t state,
+				bool stream_lock)
+{
+	struct snd_pcm_substream *s = NULL;
+	struct snd_pcm_substream *s1;
+	int res = 0, depth = 1;
+
+	snd_pcm_group_for_each_entry(s, substream) {
+		if (s != substream) {
+			if (!stream_lock)
+				mutex_lock_nested(&s->runtime->buffer_mutex, depth);
+			else if (s->pcm->nonatomic)
+				mutex_lock_nested(&s->self_group.mutex, depth);
+			else
+				spin_lock_nested(&s->self_group.lock, depth);
+			depth++;
+		}
+		res = ops->pre_action(s, state);
+		if (res < 0)
+			goto _unlock;
+	}
+	snd_pcm_group_for_each_entry(s, substream) {
+		res = ops->do_action(s, state);
+		if (res < 0) {
+			if (ops->undo_action) {
+				snd_pcm_group_for_each_entry(s1, substream) {
+					if (s1 == s) /* failed stream */
+						break;
+					ops->undo_action(s1, state);
+				}
+			}
+			s = NULL; /* unlock all */
+			goto _unlock;
+		}
+	}
+	snd_pcm_group_for_each_entry(s, substream) {
+		ops->post_action(s, state);
+	}
+ _unlock:
+	/* unlock streams */
+	snd_pcm_group_for_each_entry(s1, substream) {
+		if (s1 != substream) {
+			if (!stream_lock)
+				mutex_unlock(&s1->runtime->buffer_mutex);
+			else if (s1->pcm->nonatomic)
+				mutex_unlock(&s1->self_group.mutex);
+			else
+				spin_unlock(&s1->self_group.lock);
+		}
+		if (s1 == s)	/* end */
+			break;
+	}
+	return res;
+}
+
+/*
+ *  Note: call with stream lock
+ */
+static int snd_pcm_action_single(const struct action_ops *ops,
+				 struct snd_pcm_substream *substream,
+				 snd_pcm_state_t state)
+{
+	int res;
+	
+	res = ops->pre_action(substream, state);
+	if (res < 0)
+		return res;
+	res = ops->do_action(substream, state);
+	if (res == 0)
+		ops->post_action(substream, state);
+	else if (ops->undo_action)
+		ops->undo_action(substream, state);
+	return res;
+}
+
+static void snd_pcm_group_assign(struct snd_pcm_substream *substream,
+				 struct snd_pcm_group *new_group)
+{
+	substream->group = new_group;
+	list_move(&substream->link_list, &new_group->substreams);
+}
+
+/*
+ * Unref and unlock the group, but keep the stream lock;
+ * when the group becomes empty and no longer referred, destroy itself
+ */
+static void snd_pcm_group_unref(struct snd_pcm_group *group,
+				struct snd_pcm_substream *substream)
+{
+	bool do_free;
+
+	if (!group)
+		return;
+	do_free = refcount_dec_and_test(&group->refs);
+	snd_pcm_group_unlock(group, substream->pcm->nonatomic);
+	if (do_free)
+		kfree(group);
+}
+
+/*
+ * Lock the group inside a stream lock and reference it;
+ * return the locked group object, or NULL if not linked
+ */
+static struct snd_pcm_group *
+snd_pcm_stream_group_ref(struct snd_pcm_substream *substream)
+{
+	bool nonatomic = substream->pcm->nonatomic;
+	struct snd_pcm_group *group;
+	bool trylock;
+
+	for (;;) {
+		if (!snd_pcm_stream_linked(substream))
+			return NULL;
+		group = substream->group;
+		/* block freeing the group object */
+		refcount_inc(&group->refs);
+
+		trylock = nonatomic ? mutex_trylock(&group->mutex) :
+			spin_trylock(&group->lock);
+		if (trylock)
+			break; /* OK */
+
+		/* re-lock for avoiding ABBA deadlock */
+		snd_pcm_stream_unlock(substream);
+		snd_pcm_group_lock(group, nonatomic);
+		snd_pcm_stream_lock(substream);
+
+		/* check the group again; the above opens a small race window */
+		if (substream->group == group)
+			break; /* OK */
+		/* group changed, try again */
+		snd_pcm_group_unref(group, substream);
+	}
+	return group;
+}
+
+/*
+ *  Note: call with stream lock
+ */
+static int snd_pcm_action(const struct action_ops *ops,
+			  struct snd_pcm_substream *substream,
+			  snd_pcm_state_t state)
+{
+	struct snd_pcm_group *group;
+	int res;
+
+	group = snd_pcm_stream_group_ref(substream);
+	if (group)
+		res = snd_pcm_action_group(ops, substream, state, true);
+	else
+		res = snd_pcm_action_single(ops, substream, state);
+	snd_pcm_group_unref(group, substream);
+	return res;
+}
+
+/*
+ *  Note: don't use any locks before
+ */
+static int snd_pcm_action_lock_irq(const struct action_ops *ops,
+				   struct snd_pcm_substream *substream,
+				   snd_pcm_state_t state)
+{
+	int res;
+
+	snd_pcm_stream_lock_irq(substream);
+	res = snd_pcm_action(ops, substream, state);
+	snd_pcm_stream_unlock_irq(substream);
+	return res;
+}
+
+/*
+ */
+static int snd_pcm_action_nonatomic(const struct action_ops *ops,
+				    struct snd_pcm_substream *substream,
+				    snd_pcm_state_t state)
+{
+	int res;
+
+	/* Guarantee the group members won't change during non-atomic action */
+	down_read(&snd_pcm_link_rwsem);
+	res = snd_pcm_buffer_access_lock(substream->runtime);
+	if (res < 0)
+		goto unlock;
+	if (snd_pcm_stream_linked(substream))
+		res = snd_pcm_action_group(ops, substream, state, false);
+	else
+		res = snd_pcm_action_single(ops, substream, state);
+	snd_pcm_buffer_access_unlock(substream->runtime);
+ unlock:
+	up_read(&snd_pcm_link_rwsem);
+	return res;
+}
+
+/*
+ * start callbacks
+ */
+static int snd_pcm_pre_start(struct snd_pcm_substream *substream,
+			     snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (runtime->state != SNDRV_PCM_STATE_PREPARED)
+		return -EBADFD;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+	    !snd_pcm_playback_data(substream))
+		return -EPIPE;
+	runtime->trigger_tstamp_latched = false;
+	runtime->trigger_master = substream;
+	return 0;
+}
+
+static int snd_pcm_do_start(struct snd_pcm_substream *substream,
+			    snd_pcm_state_t state)
+{
+	int err;
+
+	if (substream->runtime->trigger_master != substream)
+		return 0;
+	err = substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_START);
+	/* XRUN happened during the start */
+	if (err == -EPIPE)
+		__snd_pcm_set_state(substream->runtime, SNDRV_PCM_STATE_XRUN);
+	return err;
+}
+
+static void snd_pcm_undo_start(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	if (substream->runtime->trigger_master == substream) {
+		substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
+		substream->runtime->stop_operating = true;
+	}
+}
+
+static void snd_pcm_post_start(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_trigger_tstamp(substream);
+	runtime->hw_ptr_jiffies = jiffies;
+	runtime->hw_ptr_buffer_jiffies = (runtime->buffer_size * HZ) / 
+							    runtime->rate;
+	__snd_pcm_set_state(runtime, state);
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+	    runtime->silence_size > 0)
+		snd_pcm_playback_silence(substream, ULONG_MAX);
+	snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSTART);
+}
+
+static const struct action_ops snd_pcm_action_start = {
+	.pre_action = snd_pcm_pre_start,
+	.do_action = snd_pcm_do_start,
+	.undo_action = snd_pcm_undo_start,
+	.post_action = snd_pcm_post_start
+};
+
+/**
+ * snd_pcm_start - start all linked streams
+ * @substream: the PCM substream instance
+ *
+ * Return: Zero if successful, or a negative error code.
+ * The stream lock must be acquired before calling this function.
+ */
+int snd_pcm_start(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_action(&snd_pcm_action_start, substream,
+			      SNDRV_PCM_STATE_RUNNING);
+}
+
+/* take the stream lock and start the streams */
+static int snd_pcm_start_lock_irq(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_action_lock_irq(&snd_pcm_action_start, substream,
+				       SNDRV_PCM_STATE_RUNNING);
+}
+
+/*
+ * stop callbacks
+ */
+static int snd_pcm_pre_stop(struct snd_pcm_substream *substream,
+			    snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+	runtime->trigger_master = substream;
+	return 0;
+}
+
+static int snd_pcm_do_stop(struct snd_pcm_substream *substream,
+			   snd_pcm_state_t state)
+{
+	if (substream->runtime->trigger_master == substream &&
+	    snd_pcm_running(substream)) {
+		substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
+		substream->runtime->stop_operating = true;
+	}
+	return 0; /* unconditionally stop all substreams */
+}
+
+static void snd_pcm_post_stop(struct snd_pcm_substream *substream,
+			      snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (runtime->state != state) {
+		snd_pcm_trigger_tstamp(substream);
+		__snd_pcm_set_state(runtime, state);
+		snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSTOP);
+	}
+	wake_up(&runtime->sleep);
+	wake_up(&runtime->tsleep);
+}
+
+static const struct action_ops snd_pcm_action_stop = {
+	.pre_action = snd_pcm_pre_stop,
+	.do_action = snd_pcm_do_stop,
+	.post_action = snd_pcm_post_stop
+};
+
+/**
+ * snd_pcm_stop - try to stop all running streams in the substream group
+ * @substream: the PCM substream instance
+ * @state: PCM state after stopping the stream
+ *
+ * The state of each stream is then changed to the given state unconditionally.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_pcm_stop(struct snd_pcm_substream *substream, snd_pcm_state_t state)
+{
+	return snd_pcm_action(&snd_pcm_action_stop, substream, state);
+}
+EXPORT_SYMBOL(snd_pcm_stop);
+
+/**
+ * snd_pcm_drain_done - stop the DMA only when the given stream is playback
+ * @substream: the PCM substream
+ *
+ * After stopping, the state is changed to SETUP.
+ * Unlike snd_pcm_stop(), this affects only the given stream.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_pcm_drain_done(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_action_single(&snd_pcm_action_stop, substream,
+				     SNDRV_PCM_STATE_SETUP);
+}
+
+/**
+ * snd_pcm_stop_xrun - stop the running streams as XRUN
+ * @substream: the PCM substream instance
+ *
+ * This stops the given running substream (and all linked substreams) as XRUN.
+ * Unlike snd_pcm_stop(), this function takes the substream lock by itself.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_pcm_stop_xrun(struct snd_pcm_substream *substream)
+{
+	unsigned long flags;
+
+	snd_pcm_stream_lock_irqsave(substream, flags);
+	if (substream->runtime && snd_pcm_running(substream))
+		__snd_pcm_xrun(substream);
+	snd_pcm_stream_unlock_irqrestore(substream, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_stop_xrun);
+
+/*
+ * pause callbacks: pass boolean (to start pause or resume) as state argument
+ */
+#define pause_pushed(state)	(__force bool)(state)
+
+static int snd_pcm_pre_pause(struct snd_pcm_substream *substream,
+			     snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (!(runtime->info & SNDRV_PCM_INFO_PAUSE))
+		return -ENOSYS;
+	if (pause_pushed(state)) {
+		if (runtime->state != SNDRV_PCM_STATE_RUNNING)
+			return -EBADFD;
+	} else if (runtime->state != SNDRV_PCM_STATE_PAUSED)
+		return -EBADFD;
+	runtime->trigger_master = substream;
+	return 0;
+}
+
+static int snd_pcm_do_pause(struct snd_pcm_substream *substream,
+			    snd_pcm_state_t state)
+{
+	if (substream->runtime->trigger_master != substream)
+		return 0;
+	/* The jiffies check in snd_pcm_update_hw_ptr*() is done by
+	 * a delta between the current jiffies, this gives a large enough
+	 * delta, effectively to skip the check once.
+	 */
+	substream->runtime->hw_ptr_jiffies = jiffies - HZ * 1000;
+	return substream->ops->trigger(substream,
+				       pause_pushed(state) ?
+				       SNDRV_PCM_TRIGGER_PAUSE_PUSH :
+				       SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
+}
+
+static void snd_pcm_undo_pause(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	if (substream->runtime->trigger_master == substream)
+		substream->ops->trigger(substream,
+					pause_pushed(state) ?
+					SNDRV_PCM_TRIGGER_PAUSE_RELEASE :
+					SNDRV_PCM_TRIGGER_PAUSE_PUSH);
+}
+
+static void snd_pcm_post_pause(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_trigger_tstamp(substream);
+	if (pause_pushed(state)) {
+		__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_PAUSED);
+		snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MPAUSE);
+		wake_up(&runtime->sleep);
+		wake_up(&runtime->tsleep);
+	} else {
+		__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_RUNNING);
+		snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MCONTINUE);
+	}
+}
+
+static const struct action_ops snd_pcm_action_pause = {
+	.pre_action = snd_pcm_pre_pause,
+	.do_action = snd_pcm_do_pause,
+	.undo_action = snd_pcm_undo_pause,
+	.post_action = snd_pcm_post_pause
+};
+
+/*
+ * Push/release the pause for all linked streams.
+ */
+static int snd_pcm_pause(struct snd_pcm_substream *substream, bool push)
+{
+	return snd_pcm_action(&snd_pcm_action_pause, substream,
+			      (__force snd_pcm_state_t)push);
+}
+
+static int snd_pcm_pause_lock_irq(struct snd_pcm_substream *substream,
+				  bool push)
+{
+	return snd_pcm_action_lock_irq(&snd_pcm_action_pause, substream,
+				       (__force snd_pcm_state_t)push);
+}
+
+#ifdef CONFIG_PM
+/* suspend callback: state argument ignored */
+
+static int snd_pcm_pre_suspend(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_SUSPENDED:
+		return -EBUSY;
+	/* unresumable PCM state; return -EBUSY for skipping suspend */
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_SETUP:
+	case SNDRV_PCM_STATE_DISCONNECTED:
+		return -EBUSY;
+	}
+	runtime->trigger_master = substream;
+	return 0;
+}
+
+static int snd_pcm_do_suspend(struct snd_pcm_substream *substream,
+			      snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (runtime->trigger_master != substream)
+		return 0;
+	if (! snd_pcm_running(substream))
+		return 0;
+	substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_SUSPEND);
+	runtime->stop_operating = true;
+	return 0; /* suspend unconditionally */
+}
+
+static void snd_pcm_post_suspend(struct snd_pcm_substream *substream,
+				 snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_trigger_tstamp(substream);
+	runtime->suspended_state = runtime->state;
+	runtime->status->suspended_state = runtime->suspended_state;
+	__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_SUSPENDED);
+	snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSUSPEND);
+	wake_up(&runtime->sleep);
+	wake_up(&runtime->tsleep);
+}
+
+static const struct action_ops snd_pcm_action_suspend = {
+	.pre_action = snd_pcm_pre_suspend,
+	.do_action = snd_pcm_do_suspend,
+	.post_action = snd_pcm_post_suspend
+};
+
+/*
+ * snd_pcm_suspend - trigger SUSPEND to all linked streams
+ * @substream: the PCM substream
+ *
+ * After this call, all streams are changed to SUSPENDED state.
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+static int snd_pcm_suspend(struct snd_pcm_substream *substream)
+{
+	int err;
+	unsigned long flags;
+
+	snd_pcm_stream_lock_irqsave(substream, flags);
+	err = snd_pcm_action(&snd_pcm_action_suspend, substream,
+			     ACTION_ARG_IGNORE);
+	snd_pcm_stream_unlock_irqrestore(substream, flags);
+	return err;
+}
+
+/**
+ * snd_pcm_suspend_all - trigger SUSPEND to all substreams in the given pcm
+ * @pcm: the PCM instance
+ *
+ * After this call, all streams are changed to SUSPENDED state.
+ *
+ * Return: Zero if successful (or @pcm is %NULL), or a negative error code.
+ */
+int snd_pcm_suspend_all(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	int stream, err = 0;
+
+	if (! pcm)
+		return 0;
+
+	for_each_pcm_substream(pcm, stream, substream) {
+		/* FIXME: the open/close code should lock this as well */
+		if (!substream->runtime)
+			continue;
+
+		/*
+		 * Skip BE dai link PCM's that are internal and may
+		 * not have their substream ops set.
+		 */
+		if (!substream->ops)
+			continue;
+
+		err = snd_pcm_suspend(substream);
+		if (err < 0 && err != -EBUSY)
+			return err;
+	}
+
+	for_each_pcm_substream(pcm, stream, substream)
+		snd_pcm_sync_stop(substream, false);
+
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_suspend_all);
+
+/* resume callbacks: state argument ignored */
+
+static int snd_pcm_pre_resume(struct snd_pcm_substream *substream,
+			      snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (!(runtime->info & SNDRV_PCM_INFO_RESUME))
+		return -ENOSYS;
+	runtime->trigger_master = substream;
+	return 0;
+}
+
+static int snd_pcm_do_resume(struct snd_pcm_substream *substream,
+			     snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (runtime->trigger_master != substream)
+		return 0;
+	/* DMA not running previously? */
+	if (runtime->suspended_state != SNDRV_PCM_STATE_RUNNING &&
+	    (runtime->suspended_state != SNDRV_PCM_STATE_DRAINING ||
+	     substream->stream != SNDRV_PCM_STREAM_PLAYBACK))
+		return 0;
+	return substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_RESUME);
+}
+
+static void snd_pcm_undo_resume(struct snd_pcm_substream *substream,
+				snd_pcm_state_t state)
+{
+	if (substream->runtime->trigger_master == substream &&
+	    snd_pcm_running(substream))
+		substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_SUSPEND);
+}
+
+static void snd_pcm_post_resume(struct snd_pcm_substream *substream,
+				snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_trigger_tstamp(substream);
+	__snd_pcm_set_state(runtime, runtime->suspended_state);
+	snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MRESUME);
+}
+
+static const struct action_ops snd_pcm_action_resume = {
+	.pre_action = snd_pcm_pre_resume,
+	.do_action = snd_pcm_do_resume,
+	.undo_action = snd_pcm_undo_resume,
+	.post_action = snd_pcm_post_resume
+};
+
+static int snd_pcm_resume(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_action_lock_irq(&snd_pcm_action_resume, substream,
+				       ACTION_ARG_IGNORE);
+}
+
+#else
+
+static int snd_pcm_resume(struct snd_pcm_substream *substream)
+{
+	return -ENOSYS;
+}
+
+#endif /* CONFIG_PM */
+
+/*
+ * xrun ioctl
+ *
+ * Change the RUNNING stream(s) to XRUN state.
+ */
+static int snd_pcm_xrun(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int result;
+
+	snd_pcm_stream_lock_irq(substream);
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_XRUN:
+		result = 0;	/* already there */
+		break;
+	case SNDRV_PCM_STATE_RUNNING:
+		__snd_pcm_xrun(substream);
+		result = 0;
+		break;
+	default:
+		result = -EBADFD;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+	return result;
+}
+
+/*
+ * reset ioctl
+ */
+/* reset callbacks:  state argument ignored */
+static int snd_pcm_pre_reset(struct snd_pcm_substream *substream,
+			     snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_RUNNING:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+	case SNDRV_PCM_STATE_SUSPENDED:
+		return 0;
+	default:
+		return -EBADFD;
+	}
+}
+
+static int snd_pcm_do_reset(struct snd_pcm_substream *substream,
+			    snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err = snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL);
+	if (err < 0)
+		return err;
+	snd_pcm_stream_lock_irq(substream);
+	runtime->hw_ptr_base = 0;
+	runtime->hw_ptr_interrupt = runtime->status->hw_ptr -
+		runtime->status->hw_ptr % runtime->period_size;
+	runtime->silence_start = runtime->status->hw_ptr;
+	runtime->silence_filled = 0;
+	snd_pcm_stream_unlock_irq(substream);
+	return 0;
+}
+
+static void snd_pcm_post_reset(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_stream_lock_irq(substream);
+	runtime->control->appl_ptr = runtime->status->hw_ptr;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+	    runtime->silence_size > 0)
+		snd_pcm_playback_silence(substream, ULONG_MAX);
+	snd_pcm_stream_unlock_irq(substream);
+}
+
+static const struct action_ops snd_pcm_action_reset = {
+	.pre_action = snd_pcm_pre_reset,
+	.do_action = snd_pcm_do_reset,
+	.post_action = snd_pcm_post_reset
+};
+
+static int snd_pcm_reset(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_action_nonatomic(&snd_pcm_action_reset, substream,
+					ACTION_ARG_IGNORE);
+}
+
+/*
+ * prepare ioctl
+ */
+/* pass f_flags as state argument */
+static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream,
+			       snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int f_flags = (__force int)state;
+
+	if (runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+	if (snd_pcm_running(substream))
+		return -EBUSY;
+	substream->f_flags = f_flags;
+	return 0;
+}
+
+static int snd_pcm_do_prepare(struct snd_pcm_substream *substream,
+			      snd_pcm_state_t state)
+{
+	int err;
+	snd_pcm_sync_stop(substream, true);
+	err = substream->ops->prepare(substream);
+	if (err < 0)
+		return err;
+	return snd_pcm_do_reset(substream, state);
+}
+
+static void snd_pcm_post_prepare(struct snd_pcm_substream *substream,
+				 snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	runtime->control->appl_ptr = runtime->status->hw_ptr;
+	snd_pcm_set_state(substream, SNDRV_PCM_STATE_PREPARED);
+}
+
+static const struct action_ops snd_pcm_action_prepare = {
+	.pre_action = snd_pcm_pre_prepare,
+	.do_action = snd_pcm_do_prepare,
+	.post_action = snd_pcm_post_prepare
+};
+
+/**
+ * snd_pcm_prepare - prepare the PCM substream to be triggerable
+ * @substream: the PCM substream instance
+ * @file: file to refer f_flags
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+static int snd_pcm_prepare(struct snd_pcm_substream *substream,
+			   struct file *file)
+{
+	int f_flags;
+
+	if (file)
+		f_flags = file->f_flags;
+	else
+		f_flags = substream->f_flags;
+
+	snd_pcm_stream_lock_irq(substream);
+	switch (substream->runtime->state) {
+	case SNDRV_PCM_STATE_PAUSED:
+		snd_pcm_pause(substream, false);
+		fallthrough;
+	case SNDRV_PCM_STATE_SUSPENDED:
+		snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
+		break;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+
+	return snd_pcm_action_nonatomic(&snd_pcm_action_prepare,
+					substream,
+					(__force snd_pcm_state_t)f_flags);
+}
+
+/*
+ * drain ioctl
+ */
+
+/* drain init callbacks: state argument ignored */
+static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream,
+				  snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_OPEN:
+	case SNDRV_PCM_STATE_DISCONNECTED:
+	case SNDRV_PCM_STATE_SUSPENDED:
+		return -EBADFD;
+	}
+	runtime->trigger_master = substream;
+	return 0;
+}
+
+static int snd_pcm_do_drain_init(struct snd_pcm_substream *substream,
+				 snd_pcm_state_t state)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		switch (runtime->state) {
+		case SNDRV_PCM_STATE_PREPARED:
+			/* start playback stream if possible */
+			if (! snd_pcm_playback_empty(substream)) {
+				snd_pcm_do_start(substream, SNDRV_PCM_STATE_DRAINING);
+				snd_pcm_post_start(substream, SNDRV_PCM_STATE_DRAINING);
+			} else {
+				__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_SETUP);
+			}
+			break;
+		case SNDRV_PCM_STATE_RUNNING:
+			__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_DRAINING);
+			break;
+		case SNDRV_PCM_STATE_XRUN:
+			__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_SETUP);
+			break;
+		default:
+			break;
+		}
+	} else {
+		/* stop running stream */
+		if (runtime->state == SNDRV_PCM_STATE_RUNNING) {
+			snd_pcm_state_t new_state;
+
+			new_state = snd_pcm_capture_avail(runtime) > 0 ?
+				SNDRV_PCM_STATE_DRAINING : SNDRV_PCM_STATE_SETUP;
+			snd_pcm_do_stop(substream, new_state);
+			snd_pcm_post_stop(substream, new_state);
+		}
+	}
+
+	if (runtime->state == SNDRV_PCM_STATE_DRAINING &&
+	    runtime->trigger_master == substream &&
+	    (runtime->hw.info & SNDRV_PCM_INFO_DRAIN_TRIGGER))
+		return substream->ops->trigger(substream,
+					       SNDRV_PCM_TRIGGER_DRAIN);
+
+	return 0;
+}
+
+static void snd_pcm_post_drain_init(struct snd_pcm_substream *substream,
+				    snd_pcm_state_t state)
+{
+}
+
+static const struct action_ops snd_pcm_action_drain_init = {
+	.pre_action = snd_pcm_pre_drain_init,
+	.do_action = snd_pcm_do_drain_init,
+	.post_action = snd_pcm_post_drain_init
+};
+
+/*
+ * Drain the stream(s).
+ * When the substream is linked, sync until the draining of all playback streams
+ * is finished.
+ * After this call, all streams are supposed to be either SETUP or DRAINING
+ * (capture only) state.
+ */
+static int snd_pcm_drain(struct snd_pcm_substream *substream,
+			 struct file *file)
+{
+	struct snd_card *card;
+	struct snd_pcm_runtime *runtime;
+	struct snd_pcm_substream *s;
+	struct snd_pcm_group *group;
+	wait_queue_entry_t wait;
+	int result = 0;
+	int nonblock = 0;
+
+	card = substream->pcm->card;
+	runtime = substream->runtime;
+
+	if (runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+
+	if (file) {
+		if (file->f_flags & O_NONBLOCK)
+			nonblock = 1;
+	} else if (substream->f_flags & O_NONBLOCK)
+		nonblock = 1;
+
+	snd_pcm_stream_lock_irq(substream);
+	/* resume pause */
+	if (runtime->state == SNDRV_PCM_STATE_PAUSED)
+		snd_pcm_pause(substream, false);
+
+	/* pre-start/stop - all running streams are changed to DRAINING state */
+	result = snd_pcm_action(&snd_pcm_action_drain_init, substream,
+				ACTION_ARG_IGNORE);
+	if (result < 0)
+		goto unlock;
+	/* in non-blocking, we don't wait in ioctl but let caller poll */
+	if (nonblock) {
+		result = -EAGAIN;
+		goto unlock;
+	}
+
+	for (;;) {
+		long tout;
+		struct snd_pcm_runtime *to_check;
+		if (signal_pending(current)) {
+			result = -ERESTARTSYS;
+			break;
+		}
+		/* find a substream to drain */
+		to_check = NULL;
+		group = snd_pcm_stream_group_ref(substream);
+		snd_pcm_group_for_each_entry(s, substream) {
+			if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
+				continue;
+			runtime = s->runtime;
+			if (runtime->state == SNDRV_PCM_STATE_DRAINING) {
+				to_check = runtime;
+				break;
+			}
+		}
+		snd_pcm_group_unref(group, substream);
+		if (!to_check)
+			break; /* all drained */
+		init_waitqueue_entry(&wait, current);
+		set_current_state(TASK_INTERRUPTIBLE);
+		add_wait_queue(&to_check->sleep, &wait);
+		snd_pcm_stream_unlock_irq(substream);
+		if (runtime->no_period_wakeup)
+			tout = MAX_SCHEDULE_TIMEOUT;
+		else {
+			tout = 100;
+			if (runtime->rate) {
+				long t = runtime->buffer_size * 1100 / runtime->rate;
+				tout = max(t, tout);
+			}
+			tout = msecs_to_jiffies(tout);
+		}
+		tout = schedule_timeout(tout);
+
+		snd_pcm_stream_lock_irq(substream);
+		group = snd_pcm_stream_group_ref(substream);
+		snd_pcm_group_for_each_entry(s, substream) {
+			if (s->runtime == to_check) {
+				remove_wait_queue(&to_check->sleep, &wait);
+				break;
+			}
+		}
+		snd_pcm_group_unref(group, substream);
+
+		if (card->shutdown) {
+			result = -ENODEV;
+			break;
+		}
+		if (tout == 0) {
+			if (substream->runtime->state == SNDRV_PCM_STATE_SUSPENDED)
+				result = -ESTRPIPE;
+			else {
+				dev_dbg(substream->pcm->card->dev,
+					"playback drain timeout (DMA or IRQ trouble?)\n");
+				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
+				result = -EIO;
+			}
+			break;
+		}
+	}
+
+ unlock:
+	snd_pcm_stream_unlock_irq(substream);
+
+	return result;
+}
+
+/*
+ * drop ioctl
+ *
+ * Immediately put all linked substreams into SETUP state.
+ */
+static int snd_pcm_drop(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+	int result = 0;
+	
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+
+	if (runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+
+	snd_pcm_stream_lock_irq(substream);
+	/* resume pause */
+	if (runtime->state == SNDRV_PCM_STATE_PAUSED)
+		snd_pcm_pause(substream, false);
+
+	snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
+	/* runtime->control->appl_ptr = runtime->status->hw_ptr; */
+	snd_pcm_stream_unlock_irq(substream);
+
+	return result;
+}
+
+
+static bool is_pcm_file(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	struct snd_pcm *pcm;
+	unsigned int minor;
+
+	if (!S_ISCHR(inode->i_mode) || imajor(inode) != snd_major)
+		return false;
+	minor = iminor(inode);
+	pcm = snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
+	if (!pcm)
+		pcm = snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_CAPTURE);
+	if (!pcm)
+		return false;
+	snd_card_unref(pcm->card);
+	return true;
+}
+
+/*
+ * PCM link handling
+ */
+static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
+{
+	int res = 0;
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream1;
+	struct snd_pcm_group *group, *target_group;
+	bool nonatomic = substream->pcm->nonatomic;
+	struct fd f = fdget(fd);
+
+	if (!f.file)
+		return -EBADFD;
+	if (!is_pcm_file(f.file)) {
+		res = -EBADFD;
+		goto _badf;
+	}
+	pcm_file = f.file->private_data;
+	substream1 = pcm_file->substream;
+
+	if (substream == substream1) {
+		res = -EINVAL;
+		goto _badf;
+	}
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group) {
+		res = -ENOMEM;
+		goto _nolock;
+	}
+	snd_pcm_group_init(group);
+
+	down_write(&snd_pcm_link_rwsem);
+	if (substream->runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    substream->runtime->state != substream1->runtime->state ||
+	    substream->pcm->nonatomic != substream1->pcm->nonatomic) {
+		res = -EBADFD;
+		goto _end;
+	}
+	if (snd_pcm_stream_linked(substream1)) {
+		res = -EALREADY;
+		goto _end;
+	}
+
+	snd_pcm_stream_lock_irq(substream);
+	if (!snd_pcm_stream_linked(substream)) {
+		snd_pcm_group_assign(substream, group);
+		group = NULL; /* assigned, don't free this one below */
+	}
+	target_group = substream->group;
+	snd_pcm_stream_unlock_irq(substream);
+
+	snd_pcm_group_lock_irq(target_group, nonatomic);
+	snd_pcm_stream_lock_nested(substream1);
+	snd_pcm_group_assign(substream1, target_group);
+	refcount_inc(&target_group->refs);
+	snd_pcm_stream_unlock(substream1);
+	snd_pcm_group_unlock_irq(target_group, nonatomic);
+ _end:
+	up_write(&snd_pcm_link_rwsem);
+ _nolock:
+	kfree(group);
+ _badf:
+	fdput(f);
+	return res;
+}
+
+static void relink_to_local(struct snd_pcm_substream *substream)
+{
+	snd_pcm_stream_lock_nested(substream);
+	snd_pcm_group_assign(substream, &substream->self_group);
+	snd_pcm_stream_unlock(substream);
+}
+
+static int snd_pcm_unlink(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_group *group;
+	bool nonatomic = substream->pcm->nonatomic;
+	bool do_free = false;
+	int res = 0;
+
+	down_write(&snd_pcm_link_rwsem);
+
+	if (!snd_pcm_stream_linked(substream)) {
+		res = -EALREADY;
+		goto _end;
+	}
+
+	group = substream->group;
+	snd_pcm_group_lock_irq(group, nonatomic);
+
+	relink_to_local(substream);
+	refcount_dec(&group->refs);
+
+	/* detach the last stream, too */
+	if (list_is_singular(&group->substreams)) {
+		relink_to_local(list_first_entry(&group->substreams,
+						 struct snd_pcm_substream,
+						 link_list));
+		do_free = refcount_dec_and_test(&group->refs);
+	}
+
+	snd_pcm_group_unlock_irq(group, nonatomic);
+	if (do_free)
+		kfree(group);
+
+       _end:
+	up_write(&snd_pcm_link_rwsem);
+	return res;
+}
+
+/*
+ * hw configurator
+ */
+static int snd_pcm_hw_rule_mul(struct snd_pcm_hw_params *params,
+			       struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval t;
+	snd_interval_mul(hw_param_interval_c(params, rule->deps[0]),
+		     hw_param_interval_c(params, rule->deps[1]), &t);
+	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static int snd_pcm_hw_rule_div(struct snd_pcm_hw_params *params,
+			       struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval t;
+	snd_interval_div(hw_param_interval_c(params, rule->deps[0]),
+		     hw_param_interval_c(params, rule->deps[1]), &t);
+	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static int snd_pcm_hw_rule_muldivk(struct snd_pcm_hw_params *params,
+				   struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval t;
+	snd_interval_muldivk(hw_param_interval_c(params, rule->deps[0]),
+			 hw_param_interval_c(params, rule->deps[1]),
+			 (unsigned long) rule->private, &t);
+	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static int snd_pcm_hw_rule_mulkdiv(struct snd_pcm_hw_params *params,
+				   struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval t;
+	snd_interval_mulkdiv(hw_param_interval_c(params, rule->deps[0]),
+			 (unsigned long) rule->private,
+			 hw_param_interval_c(params, rule->deps[1]), &t);
+	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+static int snd_pcm_hw_rule_format(struct snd_pcm_hw_params *params,
+				  struct snd_pcm_hw_rule *rule)
+{
+	snd_pcm_format_t k;
+	const struct snd_interval *i =
+				hw_param_interval_c(params, rule->deps[0]);
+	struct snd_mask m;
+	struct snd_mask *mask = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
+	snd_mask_any(&m);
+	pcm_for_each_format(k) {
+		int bits;
+		if (!snd_mask_test_format(mask, k))
+			continue;
+		bits = snd_pcm_format_physical_width(k);
+		if (bits <= 0)
+			continue; /* ignore invalid formats */
+		if ((unsigned)bits < i->min || (unsigned)bits > i->max)
+			snd_mask_reset(&m, (__force unsigned)k);
+	}
+	return snd_mask_refine(mask, &m);
+}
+
+static int snd_pcm_hw_rule_sample_bits(struct snd_pcm_hw_params *params,
+				       struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval t;
+	snd_pcm_format_t k;
+
+	t.min = UINT_MAX;
+	t.max = 0;
+	t.openmin = 0;
+	t.openmax = 0;
+	pcm_for_each_format(k) {
+		int bits;
+		if (!snd_mask_test_format(hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT), k))
+			continue;
+		bits = snd_pcm_format_physical_width(k);
+		if (bits <= 0)
+			continue; /* ignore invalid formats */
+		if (t.min > (unsigned)bits)
+			t.min = bits;
+		if (t.max < (unsigned)bits)
+			t.max = bits;
+	}
+	t.integer = 1;
+	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}
+
+#if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
+#error "Change this table"
+#endif
+
+static const unsigned int rates[] = {
+	5512, 8000, 11025, 16000, 22050, 32000, 44100,
+	48000, 64000, 88200, 96000, 176400, 192000, 352800, 384000
+};
+
+const struct snd_pcm_hw_constraint_list snd_pcm_known_rates = {
+	.count = ARRAY_SIZE(rates),
+	.list = rates,
+};
+
+static int snd_pcm_hw_rule_rate(struct snd_pcm_hw_params *params,
+				struct snd_pcm_hw_rule *rule)
+{
+	struct snd_pcm_hardware *hw = rule->private;
+	return snd_interval_list(hw_param_interval(params, rule->var),
+				 snd_pcm_known_rates.count,
+				 snd_pcm_known_rates.list, hw->rates);
+}		
+
+static int snd_pcm_hw_rule_buffer_bytes_max(struct snd_pcm_hw_params *params,
+					    struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval t;
+	struct snd_pcm_substream *substream = rule->private;
+	t.min = 0;
+	t.max = substream->buffer_bytes_max;
+	t.openmin = 0;
+	t.openmax = 0;
+	t.integer = 1;
+	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
+}		
+
+static int snd_pcm_hw_constraints_init(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
+	int k, err;
+
+	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) {
+		snd_mask_any(constrs_mask(constrs, k));
+	}
+
+	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
+		snd_interval_any(constrs_interval(constrs, k));
+	}
+
+	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_CHANNELS));
+	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_BUFFER_SIZE));
+	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_BUFFER_BYTES));
+	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_SAMPLE_BITS));
+	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_FRAME_BITS));
+
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
+				   snd_pcm_hw_rule_format, NULL,
+				   SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 
+				  snd_pcm_hw_rule_sample_bits, NULL,
+				  SNDRV_PCM_HW_PARAM_FORMAT, 
+				  SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 
+				  snd_pcm_hw_rule_div, NULL,
+				  SNDRV_PCM_HW_PARAM_FRAME_BITS, SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
+				  snd_pcm_hw_rule_mul, NULL,
+				  SNDRV_PCM_HW_PARAM_SAMPLE_BITS, SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 8,
+				  SNDRV_PCM_HW_PARAM_PERIOD_BYTES, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 8,
+				  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, 
+				  snd_pcm_hw_rule_div, NULL,
+				  SNDRV_PCM_HW_PARAM_FRAME_BITS, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
+				  SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_PERIOD_TIME, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
+				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_BUFFER_TIME, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS, 
+				  snd_pcm_hw_rule_div, NULL,
+				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
+				  snd_pcm_hw_rule_div, NULL,
+				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_PERIODS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 8,
+				  SNDRV_PCM_HW_PARAM_PERIOD_BYTES, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
+				  snd_pcm_hw_rule_muldivk, (void*) 1000000,
+				  SNDRV_PCM_HW_PARAM_PERIOD_TIME, SNDRV_PCM_HW_PARAM_RATE, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 
+				  snd_pcm_hw_rule_mul, NULL,
+				  SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_PERIODS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 8,
+				  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 
+				  snd_pcm_hw_rule_muldivk, (void*) 1000000,
+				  SNDRV_PCM_HW_PARAM_BUFFER_TIME, SNDRV_PCM_HW_PARAM_RATE, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 
+				  snd_pcm_hw_rule_muldivk, (void*) 8,
+				  SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 
+				  snd_pcm_hw_rule_muldivk, (void*) 8,
+				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_FRAME_BITS, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
+				  SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_RATE, -1);
+	if (err < 0)
+		return err;
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_TIME, 
+				  snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
+				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_RATE, -1);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_hardware *hw = &runtime->hw;
+	int err;
+	unsigned int mask = 0;
+
+        if (hw->info & SNDRV_PCM_INFO_INTERLEAVED)
+		mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_RW_INTERLEAVED);
+        if (hw->info & SNDRV_PCM_INFO_NONINTERLEAVED)
+		mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
+	if (hw_support_mmap(substream)) {
+		if (hw->info & SNDRV_PCM_INFO_INTERLEAVED)
+			mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
+		if (hw->info & SNDRV_PCM_INFO_NONINTERLEAVED)
+			mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED);
+		if (hw->info & SNDRV_PCM_INFO_COMPLEX)
+			mask |= PARAM_MASK_BIT(SNDRV_PCM_ACCESS_MMAP_COMPLEX);
+	}
+	err = snd_pcm_hw_constraint_mask(runtime, SNDRV_PCM_HW_PARAM_ACCESS, mask);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_mask64(runtime, SNDRV_PCM_HW_PARAM_FORMAT, hw->formats);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_mask(runtime, SNDRV_PCM_HW_PARAM_SUBFORMAT,
+					 PARAM_MASK_BIT(SNDRV_PCM_SUBFORMAT_STD));
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_CHANNELS,
+					   hw->channels_min, hw->channels_max);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_RATE,
+					   hw->rate_min, hw->rate_max);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
+					   hw->period_bytes_min, hw->period_bytes_max);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIODS,
+					   hw->periods_min, hw->periods_max);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
+					   hw->period_bytes_min, hw->buffer_bytes_max);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 
+				  snd_pcm_hw_rule_buffer_bytes_max, substream,
+				  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, -1);
+	if (err < 0)
+		return err;
+
+	/* FIXME: remove */
+	if (runtime->dma_bytes) {
+		err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 0, runtime->dma_bytes);
+		if (err < 0)
+			return err;
+	}
+
+	if (!(hw->rates & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))) {
+		err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
+					  snd_pcm_hw_rule_rate, hw,
+					  SNDRV_PCM_HW_PARAM_RATE, -1);
+		if (err < 0)
+			return err;
+	}
+
+	/* FIXME: this belong to lowlevel */
+	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
+
+	return 0;
+}
+
+static void pcm_release_private(struct snd_pcm_substream *substream)
+{
+	if (snd_pcm_stream_linked(substream))
+		snd_pcm_unlink(substream);
+}
+
+void snd_pcm_release_substream(struct snd_pcm_substream *substream)
+{
+	substream->ref_count--;
+	if (substream->ref_count > 0)
+		return;
+
+	snd_pcm_drop(substream);
+	if (substream->hw_opened) {
+		if (substream->runtime->state != SNDRV_PCM_STATE_OPEN)
+			do_hw_free(substream);
+		substream->ops->close(substream);
+		substream->hw_opened = 0;
+	}
+	if (cpu_latency_qos_request_active(&substream->latency_pm_qos_req))
+		cpu_latency_qos_remove_request(&substream->latency_pm_qos_req);
+	if (substream->pcm_release) {
+		substream->pcm_release(substream);
+		substream->pcm_release = NULL;
+	}
+	snd_pcm_detach_substream(substream);
+}
+EXPORT_SYMBOL(snd_pcm_release_substream);
+
+int snd_pcm_open_substream(struct snd_pcm *pcm, int stream,
+			   struct file *file,
+			   struct snd_pcm_substream **rsubstream)
+{
+	struct snd_pcm_substream *substream;
+	int err;
+
+	err = snd_pcm_attach_substream(pcm, stream, file, &substream);
+	if (err < 0)
+		return err;
+	if (substream->ref_count > 1) {
+		*rsubstream = substream;
+		return 0;
+	}
+
+	err = snd_pcm_hw_constraints_init(substream);
+	if (err < 0) {
+		pcm_dbg(pcm, "snd_pcm_hw_constraints_init failed\n");
+		goto error;
+	}
+
+	err = substream->ops->open(substream);
+	if (err < 0)
+		goto error;
+
+	substream->hw_opened = 1;
+
+	err = snd_pcm_hw_constraints_complete(substream);
+	if (err < 0) {
+		pcm_dbg(pcm, "snd_pcm_hw_constraints_complete failed\n");
+		goto error;
+	}
+
+	/* automatically set EXPLICIT_SYNC flag in the managed mode whenever
+	 * the DMA buffer requires it
+	 */
+	if (substream->managed_buffer_alloc &&
+	    substream->dma_buffer.dev.need_sync)
+		substream->runtime->hw.info |= SNDRV_PCM_INFO_EXPLICIT_SYNC;
+
+	*rsubstream = substream;
+	return 0;
+
+ error:
+	snd_pcm_release_substream(substream);
+	return err;
+}
+EXPORT_SYMBOL(snd_pcm_open_substream);
+
+static int snd_pcm_open_file(struct file *file,
+			     struct snd_pcm *pcm,
+			     int stream)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	int err;
+
+	err = snd_pcm_open_substream(pcm, stream, file, &substream);
+	if (err < 0)
+		return err;
+
+	pcm_file = kzalloc(sizeof(*pcm_file), GFP_KERNEL);
+	if (pcm_file == NULL) {
+		snd_pcm_release_substream(substream);
+		return -ENOMEM;
+	}
+	pcm_file->substream = substream;
+	if (substream->ref_count == 1)
+		substream->pcm_release = pcm_release_private;
+	file->private_data = pcm_file;
+
+	return 0;
+}
+
+static int snd_pcm_playback_open(struct inode *inode, struct file *file)
+{
+	struct snd_pcm *pcm;
+	int err = nonseekable_open(inode, file);
+	if (err < 0)
+		return err;
+	pcm = snd_lookup_minor_data(iminor(inode),
+				    SNDRV_DEVICE_TYPE_PCM_PLAYBACK);
+	err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_PLAYBACK);
+	if (pcm)
+		snd_card_unref(pcm->card);
+	return err;
+}
+
+static int snd_pcm_capture_open(struct inode *inode, struct file *file)
+{
+	struct snd_pcm *pcm;
+	int err = nonseekable_open(inode, file);
+	if (err < 0)
+		return err;
+	pcm = snd_lookup_minor_data(iminor(inode),
+				    SNDRV_DEVICE_TYPE_PCM_CAPTURE);
+	err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_CAPTURE);
+	if (pcm)
+		snd_card_unref(pcm->card);
+	return err;
+}
+
+static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream)
+{
+	int err;
+	wait_queue_entry_t wait;
+
+	if (pcm == NULL) {
+		err = -ENODEV;
+		goto __error1;
+	}
+	err = snd_card_file_add(pcm->card, file);
+	if (err < 0)
+		goto __error1;
+	if (!try_module_get(pcm->card->module)) {
+		err = -EFAULT;
+		goto __error2;
+	}
+	init_waitqueue_entry(&wait, current);
+	add_wait_queue(&pcm->open_wait, &wait);
+	mutex_lock(&pcm->open_mutex);
+	while (1) {
+		err = snd_pcm_open_file(file, pcm, stream);
+		if (err >= 0)
+			break;
+		if (err == -EAGAIN) {
+			if (file->f_flags & O_NONBLOCK) {
+				err = -EBUSY;
+				break;
+			}
+		} else
+			break;
+		set_current_state(TASK_INTERRUPTIBLE);
+		mutex_unlock(&pcm->open_mutex);
+		schedule();
+		mutex_lock(&pcm->open_mutex);
+		if (pcm->card->shutdown) {
+			err = -ENODEV;
+			break;
+		}
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+	}
+	remove_wait_queue(&pcm->open_wait, &wait);
+	mutex_unlock(&pcm->open_mutex);
+	if (err < 0)
+		goto __error;
+	return err;
+
+      __error:
+	module_put(pcm->card->module);
+      __error2:
+      	snd_card_file_remove(pcm->card, file);
+      __error1:
+      	return err;
+}
+
+static int snd_pcm_release(struct inode *inode, struct file *file)
+{
+	struct snd_pcm *pcm;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_file *pcm_file;
+
+	pcm_file = file->private_data;
+	substream = pcm_file->substream;
+	if (snd_BUG_ON(!substream))
+		return -ENXIO;
+	pcm = substream->pcm;
+
+	/* block until the device gets woken up as it may touch the hardware */
+	snd_power_wait(pcm->card);
+
+	mutex_lock(&pcm->open_mutex);
+	snd_pcm_release_substream(substream);
+	kfree(pcm_file);
+	mutex_unlock(&pcm->open_mutex);
+	wake_up(&pcm->open_wait);
+	module_put(pcm->card->module);
+	snd_card_file_remove(pcm->card, file);
+	return 0;
+}
+
+/* check and update PCM state; return 0 or a negative error
+ * call this inside PCM lock
+ */
+static int do_pcm_hwsync(struct snd_pcm_substream *substream)
+{
+	switch (substream->runtime->state) {
+	case SNDRV_PCM_STATE_DRAINING:
+		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+			return -EBADFD;
+		fallthrough;
+	case SNDRV_PCM_STATE_RUNNING:
+		return snd_pcm_update_hw_ptr(substream);
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+		return 0;
+	case SNDRV_PCM_STATE_SUSPENDED:
+		return -ESTRPIPE;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
+	default:
+		return -EBADFD;
+	}
+}
+
+/* increase the appl_ptr; returns the processed frames or a negative error */
+static snd_pcm_sframes_t forward_appl_ptr(struct snd_pcm_substream *substream,
+					  snd_pcm_uframes_t frames,
+					   snd_pcm_sframes_t avail)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_sframes_t appl_ptr;
+	int ret;
+
+	if (avail <= 0)
+		return 0;
+	if (frames > (snd_pcm_uframes_t)avail)
+		frames = avail;
+	appl_ptr = runtime->control->appl_ptr + frames;
+	if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
+		appl_ptr -= runtime->boundary;
+	ret = pcm_lib_apply_appl_ptr(substream, appl_ptr);
+	return ret < 0 ? ret : frames;
+}
+
+/* decrease the appl_ptr; returns the processed frames or zero for error */
+static snd_pcm_sframes_t rewind_appl_ptr(struct snd_pcm_substream *substream,
+					 snd_pcm_uframes_t frames,
+					 snd_pcm_sframes_t avail)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_sframes_t appl_ptr;
+	int ret;
+
+	if (avail <= 0)
+		return 0;
+	if (frames > (snd_pcm_uframes_t)avail)
+		frames = avail;
+	appl_ptr = runtime->control->appl_ptr - frames;
+	if (appl_ptr < 0)
+		appl_ptr += runtime->boundary;
+	ret = pcm_lib_apply_appl_ptr(substream, appl_ptr);
+	/* NOTE: we return zero for errors because PulseAudio gets depressed
+	 * upon receiving an error from rewind ioctl and stops processing
+	 * any longer.  Returning zero means that no rewind is done, so
+	 * it's not absolutely wrong to answer like that.
+	 */
+	return ret < 0 ? 0 : frames;
+}
+
+static snd_pcm_sframes_t snd_pcm_rewind(struct snd_pcm_substream *substream,
+					snd_pcm_uframes_t frames)
+{
+	snd_pcm_sframes_t ret;
+
+	if (frames == 0)
+		return 0;
+
+	snd_pcm_stream_lock_irq(substream);
+	ret = do_pcm_hwsync(substream);
+	if (!ret)
+		ret = rewind_appl_ptr(substream, frames,
+				      snd_pcm_hw_avail(substream));
+	snd_pcm_stream_unlock_irq(substream);
+	if (ret >= 0)
+		snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+	return ret;
+}
+
+static snd_pcm_sframes_t snd_pcm_forward(struct snd_pcm_substream *substream,
+					 snd_pcm_uframes_t frames)
+{
+	snd_pcm_sframes_t ret;
+
+	if (frames == 0)
+		return 0;
+
+	snd_pcm_stream_lock_irq(substream);
+	ret = do_pcm_hwsync(substream);
+	if (!ret)
+		ret = forward_appl_ptr(substream, frames,
+				       snd_pcm_avail(substream));
+	snd_pcm_stream_unlock_irq(substream);
+	if (ret >= 0)
+		snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+	return ret;
+}
+
+static int snd_pcm_delay(struct snd_pcm_substream *substream,
+			 snd_pcm_sframes_t *delay)
+{
+	int err;
+
+	snd_pcm_stream_lock_irq(substream);
+	err = do_pcm_hwsync(substream);
+	if (delay && !err)
+		*delay = snd_pcm_calc_delay(substream);
+	snd_pcm_stream_unlock_irq(substream);
+	snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
+
+	return err;
+}
+		
+static inline int snd_pcm_hwsync(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_delay(substream, NULL);
+}
+
+static int snd_pcm_sync_ptr(struct snd_pcm_substream *substream,
+			    struct snd_pcm_sync_ptr __user *_sync_ptr)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_pcm_sync_ptr sync_ptr;
+	volatile struct snd_pcm_mmap_status *status;
+	volatile struct snd_pcm_mmap_control *control;
+	int err;
+
+	memset(&sync_ptr, 0, sizeof(sync_ptr));
+	if (get_user(sync_ptr.flags, (unsigned __user *)&(_sync_ptr->flags)))
+		return -EFAULT;
+	if (copy_from_user(&sync_ptr.c.control, &(_sync_ptr->c.control), sizeof(struct snd_pcm_mmap_control)))
+		return -EFAULT;	
+	status = runtime->status;
+	control = runtime->control;
+	if (sync_ptr.flags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
+		err = snd_pcm_hwsync(substream);
+		if (err < 0)
+			return err;
+	}
+	snd_pcm_stream_lock_irq(substream);
+	if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL)) {
+		err = pcm_lib_apply_appl_ptr(substream,
+					     sync_ptr.c.control.appl_ptr);
+		if (err < 0) {
+			snd_pcm_stream_unlock_irq(substream);
+			return err;
+		}
+	} else {
+		sync_ptr.c.control.appl_ptr = control->appl_ptr;
+	}
+	if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
+		control->avail_min = sync_ptr.c.control.avail_min;
+	else
+		sync_ptr.c.control.avail_min = control->avail_min;
+	sync_ptr.s.status.state = status->state;
+	sync_ptr.s.status.hw_ptr = status->hw_ptr;
+	sync_ptr.s.status.tstamp = status->tstamp;
+	sync_ptr.s.status.suspended_state = status->suspended_state;
+	sync_ptr.s.status.audio_tstamp = status->audio_tstamp;
+	snd_pcm_stream_unlock_irq(substream);
+	if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL))
+		snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+	if (copy_to_user(_sync_ptr, &sync_ptr, sizeof(sync_ptr)))
+		return -EFAULT;
+	return 0;
+}
+
+struct snd_pcm_mmap_status32 {
+	snd_pcm_state_t state;
+	s32 pad1;
+	u32 hw_ptr;
+	s32 tstamp_sec;
+	s32 tstamp_nsec;
+	snd_pcm_state_t suspended_state;
+	s32 audio_tstamp_sec;
+	s32 audio_tstamp_nsec;
+} __attribute__((packed));
+
+struct snd_pcm_mmap_control32 {
+	u32 appl_ptr;
+	u32 avail_min;
+};
+
+struct snd_pcm_sync_ptr32 {
+	u32 flags;
+	union {
+		struct snd_pcm_mmap_status32 status;
+		unsigned char reserved[64];
+	} s;
+	union {
+		struct snd_pcm_mmap_control32 control;
+		unsigned char reserved[64];
+	} c;
+} __attribute__((packed));
+
+/* recalcuate the boundary within 32bit */
+static snd_pcm_uframes_t recalculate_boundary(struct snd_pcm_runtime *runtime)
+{
+	snd_pcm_uframes_t boundary;
+
+	if (! runtime->buffer_size)
+		return 0;
+	boundary = runtime->buffer_size;
+	while (boundary * 2 <= 0x7fffffffUL - runtime->buffer_size)
+		boundary *= 2;
+	return boundary;
+}
+
+static int snd_pcm_ioctl_sync_ptr_compat(struct snd_pcm_substream *substream,
+					 struct snd_pcm_sync_ptr32 __user *src)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	volatile struct snd_pcm_mmap_status *status;
+	volatile struct snd_pcm_mmap_control *control;
+	u32 sflags;
+	struct snd_pcm_mmap_control scontrol;
+	struct snd_pcm_mmap_status sstatus;
+	snd_pcm_uframes_t boundary;
+	int err;
+
+	if (snd_BUG_ON(!runtime))
+		return -EINVAL;
+
+	if (get_user(sflags, &src->flags) ||
+	    get_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
+	    get_user(scontrol.avail_min, &src->c.control.avail_min))
+		return -EFAULT;
+	if (sflags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
+		err = snd_pcm_hwsync(substream);
+		if (err < 0)
+			return err;
+	}
+	status = runtime->status;
+	control = runtime->control;
+	boundary = recalculate_boundary(runtime);
+	if (! boundary)
+		boundary = 0x7fffffff;
+	snd_pcm_stream_lock_irq(substream);
+	/* FIXME: we should consider the boundary for the sync from app */
+	if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL)) {
+		err = pcm_lib_apply_appl_ptr(substream,
+				scontrol.appl_ptr);
+		if (err < 0) {
+			snd_pcm_stream_unlock_irq(substream);
+			return err;
+		}
+	} else
+		scontrol.appl_ptr = control->appl_ptr % boundary;
+	if (!(sflags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
+		control->avail_min = scontrol.avail_min;
+	else
+		scontrol.avail_min = control->avail_min;
+	sstatus.state = status->state;
+	sstatus.hw_ptr = status->hw_ptr % boundary;
+	sstatus.tstamp = status->tstamp;
+	sstatus.suspended_state = status->suspended_state;
+	sstatus.audio_tstamp = status->audio_tstamp;
+	snd_pcm_stream_unlock_irq(substream);
+	if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL))
+		snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
+	if (put_user(sstatus.state, &src->s.status.state) ||
+	    put_user(sstatus.hw_ptr, &src->s.status.hw_ptr) ||
+	    put_user(sstatus.tstamp.tv_sec, &src->s.status.tstamp_sec) ||
+	    put_user(sstatus.tstamp.tv_nsec, &src->s.status.tstamp_nsec) ||
+	    put_user(sstatus.suspended_state, &src->s.status.suspended_state) ||
+	    put_user(sstatus.audio_tstamp.tv_sec, &src->s.status.audio_tstamp_sec) ||
+	    put_user(sstatus.audio_tstamp.tv_nsec, &src->s.status.audio_tstamp_nsec) ||
+	    put_user(scontrol.appl_ptr, &src->c.control.appl_ptr) ||
+	    put_user(scontrol.avail_min, &src->c.control.avail_min))
+		return -EFAULT;
+
+	return 0;
+}
+#define __SNDRV_PCM_IOCTL_SYNC_PTR32 _IOWR('A', 0x23, struct snd_pcm_sync_ptr32)
+
+static int snd_pcm_tstamp(struct snd_pcm_substream *substream, int __user *_arg)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int arg;
+	
+	if (get_user(arg, _arg))
+		return -EFAULT;
+	if (arg < 0 || arg > SNDRV_PCM_TSTAMP_TYPE_LAST)
+		return -EINVAL;
+	runtime->tstamp_type = arg;
+	return 0;
+}
+
+static int snd_pcm_xferi_frames_ioctl(struct snd_pcm_substream *substream,
+				      struct snd_xferi __user *_xferi)
+{
+	struct snd_xferi xferi;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_sframes_t result;
+
+	if (runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+	if (put_user(0, &_xferi->result))
+		return -EFAULT;
+	if (copy_from_user(&xferi, _xferi, sizeof(xferi)))
+		return -EFAULT;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		result = snd_pcm_lib_write(substream, xferi.buf, xferi.frames);
+	else
+		result = snd_pcm_lib_read(substream, xferi.buf, xferi.frames);
+	if (put_user(result, &_xferi->result))
+		return -EFAULT;
+	return result < 0 ? result : 0;
+}
+
+static int snd_pcm_xfern_frames_ioctl(struct snd_pcm_substream *substream,
+				      struct snd_xfern __user *_xfern)
+{
+	struct snd_xfern xfern;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	void *bufs;
+	snd_pcm_sframes_t result;
+
+	if (runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+	if (runtime->channels > 128)
+		return -EINVAL;
+	if (put_user(0, &_xfern->result))
+		return -EFAULT;
+	if (copy_from_user(&xfern, _xfern, sizeof(xfern)))
+		return -EFAULT;
+
+	bufs = memdup_user(xfern.bufs, sizeof(void *) * runtime->channels);
+	if (IS_ERR(bufs))
+		return PTR_ERR(bufs);
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		result = snd_pcm_lib_writev(substream, bufs, xfern.frames);
+	else
+		result = snd_pcm_lib_readv(substream, bufs, xfern.frames);
+	kfree(bufs);
+	if (put_user(result, &_xfern->result))
+		return -EFAULT;
+	return result < 0 ? result : 0;
+}
+
+static int snd_pcm_rewind_ioctl(struct snd_pcm_substream *substream,
+				snd_pcm_uframes_t __user *_frames)
+{
+	snd_pcm_uframes_t frames;
+	snd_pcm_sframes_t result;
+
+	if (get_user(frames, _frames))
+		return -EFAULT;
+	if (put_user(0, _frames))
+		return -EFAULT;
+	result = snd_pcm_rewind(substream, frames);
+	if (put_user(result, _frames))
+		return -EFAULT;
+	return result < 0 ? result : 0;
+}
+
+static int snd_pcm_forward_ioctl(struct snd_pcm_substream *substream,
+				 snd_pcm_uframes_t __user *_frames)
+{
+	snd_pcm_uframes_t frames;
+	snd_pcm_sframes_t result;
+
+	if (get_user(frames, _frames))
+		return -EFAULT;
+	if (put_user(0, _frames))
+		return -EFAULT;
+	result = snd_pcm_forward(substream, frames);
+	if (put_user(result, _frames))
+		return -EFAULT;
+	return result < 0 ? result : 0;
+}
+
+static int snd_pcm_common_ioctl(struct file *file,
+				 struct snd_pcm_substream *substream,
+				 unsigned int cmd, void __user *arg)
+{
+	struct snd_pcm_file *pcm_file = file->private_data;
+	int res;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+
+	if (substream->runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+
+	res = snd_power_wait(substream->pcm->card);
+	if (res < 0)
+		return res;
+
+	switch (cmd) {
+	case SNDRV_PCM_IOCTL_PVERSION:
+		return put_user(SNDRV_PCM_VERSION, (int __user *)arg) ? -EFAULT : 0;
+	case SNDRV_PCM_IOCTL_INFO:
+		return snd_pcm_info_user(substream, arg);
+	case SNDRV_PCM_IOCTL_TSTAMP:	/* just for compatibility */
+		return 0;
+	case SNDRV_PCM_IOCTL_TTSTAMP:
+		return snd_pcm_tstamp(substream, arg);
+	case SNDRV_PCM_IOCTL_USER_PVERSION:
+		if (get_user(pcm_file->user_pversion,
+			     (unsigned int __user *)arg))
+			return -EFAULT;
+		return 0;
+	case SNDRV_PCM_IOCTL_HW_REFINE:
+		return snd_pcm_hw_refine_user(substream, arg);
+	case SNDRV_PCM_IOCTL_HW_PARAMS:
+		return snd_pcm_hw_params_user(substream, arg);
+	case SNDRV_PCM_IOCTL_HW_FREE:
+		return snd_pcm_hw_free(substream);
+	case SNDRV_PCM_IOCTL_SW_PARAMS:
+		return snd_pcm_sw_params_user(substream, arg);
+	case SNDRV_PCM_IOCTL_STATUS32:
+		return snd_pcm_status_user32(substream, arg, false);
+	case SNDRV_PCM_IOCTL_STATUS_EXT32:
+		return snd_pcm_status_user32(substream, arg, true);
+	case SNDRV_PCM_IOCTL_STATUS64:
+		return snd_pcm_status_user64(substream, arg, false);
+	case SNDRV_PCM_IOCTL_STATUS_EXT64:
+		return snd_pcm_status_user64(substream, arg, true);
+	case SNDRV_PCM_IOCTL_CHANNEL_INFO:
+		return snd_pcm_channel_info_user(substream, arg);
+	case SNDRV_PCM_IOCTL_PREPARE:
+		return snd_pcm_prepare(substream, file);
+	case SNDRV_PCM_IOCTL_RESET:
+		return snd_pcm_reset(substream);
+	case SNDRV_PCM_IOCTL_START:
+		return snd_pcm_start_lock_irq(substream);
+	case SNDRV_PCM_IOCTL_LINK:
+		return snd_pcm_link(substream, (int)(unsigned long) arg);
+	case SNDRV_PCM_IOCTL_UNLINK:
+		return snd_pcm_unlink(substream);
+	case SNDRV_PCM_IOCTL_RESUME:
+		return snd_pcm_resume(substream);
+	case SNDRV_PCM_IOCTL_XRUN:
+		return snd_pcm_xrun(substream);
+	case SNDRV_PCM_IOCTL_HWSYNC:
+		return snd_pcm_hwsync(substream);
+	case SNDRV_PCM_IOCTL_DELAY:
+	{
+		snd_pcm_sframes_t delay = 0;
+		snd_pcm_sframes_t __user *res = arg;
+		int err;
+
+		err = snd_pcm_delay(substream, &delay);
+		if (err)
+			return err;
+		if (put_user(delay, res))
+			return -EFAULT;
+		return 0;
+	}
+	case __SNDRV_PCM_IOCTL_SYNC_PTR32:
+		return snd_pcm_ioctl_sync_ptr_compat(substream, arg);
+	case __SNDRV_PCM_IOCTL_SYNC_PTR64:
+		return snd_pcm_sync_ptr(substream, arg);
+#ifdef CONFIG_SND_SUPPORT_OLD_API
+	case SNDRV_PCM_IOCTL_HW_REFINE_OLD:
+		return snd_pcm_hw_refine_old_user(substream, arg);
+	case SNDRV_PCM_IOCTL_HW_PARAMS_OLD:
+		return snd_pcm_hw_params_old_user(substream, arg);
+#endif
+	case SNDRV_PCM_IOCTL_DRAIN:
+		return snd_pcm_drain(substream, file);
+	case SNDRV_PCM_IOCTL_DROP:
+		return snd_pcm_drop(substream);
+	case SNDRV_PCM_IOCTL_PAUSE:
+		return snd_pcm_pause_lock_irq(substream, (unsigned long)arg);
+	case SNDRV_PCM_IOCTL_WRITEI_FRAMES:
+	case SNDRV_PCM_IOCTL_READI_FRAMES:
+		return snd_pcm_xferi_frames_ioctl(substream, arg);
+	case SNDRV_PCM_IOCTL_WRITEN_FRAMES:
+	case SNDRV_PCM_IOCTL_READN_FRAMES:
+		return snd_pcm_xfern_frames_ioctl(substream, arg);
+	case SNDRV_PCM_IOCTL_REWIND:
+		return snd_pcm_rewind_ioctl(substream, arg);
+	case SNDRV_PCM_IOCTL_FORWARD:
+		return snd_pcm_forward_ioctl(substream, arg);
+	}
+	pcm_dbg(substream->pcm, "unknown ioctl = 0x%x\n", cmd);
+	return -ENOTTY;
+}
+
+static long snd_pcm_ioctl(struct file *file, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct snd_pcm_file *pcm_file;
+
+	pcm_file = file->private_data;
+
+	if (((cmd >> 8) & 0xff) != 'A')
+		return -ENOTTY;
+
+	return snd_pcm_common_ioctl(file, pcm_file->substream, cmd,
+				     (void __user *)arg);
+}
+
+/**
+ * snd_pcm_kernel_ioctl - Execute PCM ioctl in the kernel-space
+ * @substream: PCM substream
+ * @cmd: IOCTL cmd
+ * @arg: IOCTL argument
+ *
+ * The function is provided primarily for OSS layer and USB gadget drivers,
+ * and it allows only the limited set of ioctls (hw_params, sw_params,
+ * prepare, start, drain, drop, forward).
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream,
+			 unsigned int cmd, void *arg)
+{
+	snd_pcm_uframes_t *frames = arg;
+	snd_pcm_sframes_t result;
+	
+	if (substream->runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+
+	switch (cmd) {
+	case SNDRV_PCM_IOCTL_FORWARD:
+	{
+		/* provided only for OSS; capture-only and no value returned */
+		if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
+			return -EINVAL;
+		result = snd_pcm_forward(substream, *frames);
+		return result < 0 ? result : 0;
+	}
+	case SNDRV_PCM_IOCTL_HW_PARAMS:
+		return snd_pcm_hw_params(substream, arg);
+	case SNDRV_PCM_IOCTL_SW_PARAMS:
+		return snd_pcm_sw_params(substream, arg);
+	case SNDRV_PCM_IOCTL_PREPARE:
+		return snd_pcm_prepare(substream, NULL);
+	case SNDRV_PCM_IOCTL_START:
+		return snd_pcm_start_lock_irq(substream);
+	case SNDRV_PCM_IOCTL_DRAIN:
+		return snd_pcm_drain(substream, NULL);
+	case SNDRV_PCM_IOCTL_DROP:
+		return snd_pcm_drop(substream);
+	case SNDRV_PCM_IOCTL_DELAY:
+		return snd_pcm_delay(substream, frames);
+	default:
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL(snd_pcm_kernel_ioctl);
+
+static ssize_t snd_pcm_read(struct file *file, char __user *buf, size_t count,
+			    loff_t * offset)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t result;
+
+	pcm_file = file->private_data;
+	substream = pcm_file->substream;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+	if (!frame_aligned(runtime, count))
+		return -EINVAL;
+	count = bytes_to_frames(runtime, count);
+	result = snd_pcm_lib_read(substream, buf, count);
+	if (result > 0)
+		result = frames_to_bytes(runtime, result);
+	return result;
+}
+
+static ssize_t snd_pcm_write(struct file *file, const char __user *buf,
+			     size_t count, loff_t * offset)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t result;
+
+	pcm_file = file->private_data;
+	substream = pcm_file->substream;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+	if (!frame_aligned(runtime, count))
+		return -EINVAL;
+	count = bytes_to_frames(runtime, count);
+	result = snd_pcm_lib_write(substream, buf, count);
+	if (result > 0)
+		result = frames_to_bytes(runtime, result);
+	return result;
+}
+
+static ssize_t snd_pcm_readv(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t result;
+	unsigned long i;
+	void __user **bufs;
+	snd_pcm_uframes_t frames;
+	const struct iovec *iov = iter_iov(to);
+
+	pcm_file = iocb->ki_filp->private_data;
+	substream = pcm_file->substream;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+	if (!to->user_backed)
+		return -EINVAL;
+	if (to->nr_segs > 1024 || to->nr_segs != runtime->channels)
+		return -EINVAL;
+	if (!frame_aligned(runtime, iov->iov_len))
+		return -EINVAL;
+	frames = bytes_to_samples(runtime, iov->iov_len);
+	bufs = kmalloc_array(to->nr_segs, sizeof(void *), GFP_KERNEL);
+	if (bufs == NULL)
+		return -ENOMEM;
+	for (i = 0; i < to->nr_segs; ++i) {
+		bufs[i] = iov->iov_base;
+		iov++;
+	}
+	result = snd_pcm_lib_readv(substream, bufs, frames);
+	if (result > 0)
+		result = frames_to_bytes(runtime, result);
+	kfree(bufs);
+	return result;
+}
+
+static ssize_t snd_pcm_writev(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	snd_pcm_sframes_t result;
+	unsigned long i;
+	void __user **bufs;
+	snd_pcm_uframes_t frames;
+	const struct iovec *iov = iter_iov(from);
+
+	pcm_file = iocb->ki_filp->private_data;
+	substream = pcm_file->substream;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN ||
+	    runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+	if (!from->user_backed)
+		return -EINVAL;
+	if (from->nr_segs > 128 || from->nr_segs != runtime->channels ||
+	    !frame_aligned(runtime, iov->iov_len))
+		return -EINVAL;
+	frames = bytes_to_samples(runtime, iov->iov_len);
+	bufs = kmalloc_array(from->nr_segs, sizeof(void *), GFP_KERNEL);
+	if (bufs == NULL)
+		return -ENOMEM;
+	for (i = 0; i < from->nr_segs; ++i) {
+		bufs[i] = iov->iov_base;
+		iov++;
+	}
+	result = snd_pcm_lib_writev(substream, bufs, frames);
+	if (result > 0)
+		result = frames_to_bytes(runtime, result);
+	kfree(bufs);
+	return result;
+}
+
+static __poll_t snd_pcm_poll(struct file *file, poll_table *wait)
+{
+	struct snd_pcm_file *pcm_file;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	__poll_t mask, ok;
+	snd_pcm_uframes_t avail;
+
+	pcm_file = file->private_data;
+
+	substream = pcm_file->substream;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		ok = EPOLLOUT | EPOLLWRNORM;
+	else
+		ok = EPOLLIN | EPOLLRDNORM;
+	if (PCM_RUNTIME_CHECK(substream))
+		return ok | EPOLLERR;
+
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return ok | EPOLLERR;
+
+	poll_wait(file, &runtime->sleep, wait);
+
+	mask = 0;
+	snd_pcm_stream_lock_irq(substream);
+	avail = snd_pcm_avail(substream);
+	switch (runtime->state) {
+	case SNDRV_PCM_STATE_RUNNING:
+	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
+		if (avail >= runtime->control->avail_min)
+			mask = ok;
+		break;
+	case SNDRV_PCM_STATE_DRAINING:
+		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+			mask = ok;
+			if (!avail)
+				mask |= EPOLLERR;
+		}
+		break;
+	default:
+		mask = ok | EPOLLERR;
+		break;
+	}
+	snd_pcm_stream_unlock_irq(substream);
+	return mask;
+}
+
+/*
+ * mmap support
+ */
+
+/*
+ * Only on coherent architectures, we can mmap the status and the control records
+ * for effcient data transfer.  On others, we have to use HWSYNC ioctl...
+ */
+#if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_ALPHA)
+/*
+ * mmap status record
+ */
+static vm_fault_t snd_pcm_mmap_status_fault(struct vm_fault *vmf)
+{
+	struct snd_pcm_substream *substream = vmf->vma->vm_private_data;
+	struct snd_pcm_runtime *runtime;
+	
+	if (substream == NULL)
+		return VM_FAULT_SIGBUS;
+	runtime = substream->runtime;
+	vmf->page = virt_to_page(runtime->status);
+	get_page(vmf->page);
+	return 0;
+}
+
+static const struct vm_operations_struct snd_pcm_vm_ops_status =
+{
+	.fault =	snd_pcm_mmap_status_fault,
+};
+
+static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file,
+			       struct vm_area_struct *area)
+{
+	long size;
+	if (!(area->vm_flags & VM_READ))
+		return -EINVAL;
+	size = area->vm_end - area->vm_start;
+	if (size != PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)))
+		return -EINVAL;
+	area->vm_ops = &snd_pcm_vm_ops_status;
+	area->vm_private_data = substream;
+	vm_flags_mod(area, VM_DONTEXPAND | VM_DONTDUMP,
+		     VM_WRITE | VM_MAYWRITE);
+
+	return 0;
+}
+
+/*
+ * mmap control record
+ */
+static vm_fault_t snd_pcm_mmap_control_fault(struct vm_fault *vmf)
+{
+	struct snd_pcm_substream *substream = vmf->vma->vm_private_data;
+	struct snd_pcm_runtime *runtime;
+	
+	if (substream == NULL)
+		return VM_FAULT_SIGBUS;
+	runtime = substream->runtime;
+	vmf->page = virt_to_page(runtime->control);
+	get_page(vmf->page);
+	return 0;
+}
+
+static const struct vm_operations_struct snd_pcm_vm_ops_control =
+{
+	.fault =	snd_pcm_mmap_control_fault,
+};
+
+static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file *file,
+				struct vm_area_struct *area)
+{
+	long size;
+	if (!(area->vm_flags & VM_READ))
+		return -EINVAL;
+	size = area->vm_end - area->vm_start;
+	if (size != PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)))
+		return -EINVAL;
+	area->vm_ops = &snd_pcm_vm_ops_control;
+	area->vm_private_data = substream;
+	vm_flags_set(area, VM_DONTEXPAND | VM_DONTDUMP);
+	return 0;
+}
+
+static bool pcm_status_mmap_allowed(struct snd_pcm_file *pcm_file)
+{
+	/* If drivers require the explicit sync (typically for non-coherent
+	 * pages), we have to disable the mmap of status and control data
+	 * to enforce the control via SYNC_PTR ioctl.
+	 */
+	if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_EXPLICIT_SYNC)
+		return false;
+	/* See pcm_control_mmap_allowed() below.
+	 * Since older alsa-lib requires both status and control mmaps to be
+	 * coupled, we have to disable the status mmap for old alsa-lib, too.
+	 */
+	if (pcm_file->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 14) &&
+	    (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_SYNC_APPLPTR))
+		return false;
+	return true;
+}
+
+static bool pcm_control_mmap_allowed(struct snd_pcm_file *pcm_file)
+{
+	if (pcm_file->no_compat_mmap)
+		return false;
+	/* see above */
+	if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_EXPLICIT_SYNC)
+		return false;
+	/* Disallow the control mmap when SYNC_APPLPTR flag is set;
+	 * it enforces the user-space to fall back to snd_pcm_sync_ptr(),
+	 * thus it effectively assures the manual update of appl_ptr.
+	 */
+	if (pcm_file->substream->runtime->hw.info & SNDRV_PCM_INFO_SYNC_APPLPTR)
+		return false;
+	return true;
+}
+
+#else /* ! coherent mmap */
+/*
+ * don't support mmap for status and control records.
+ */
+#define pcm_status_mmap_allowed(pcm_file)	false
+#define pcm_control_mmap_allowed(pcm_file)	false
+
+static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file,
+			       struct vm_area_struct *area)
+{
+	return -ENXIO;
+}
+static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file *file,
+				struct vm_area_struct *area)
+{
+	return -ENXIO;
+}
+#endif /* coherent mmap */
+
+/*
+ * fault callback for mmapping a RAM page
+ */
+static vm_fault_t snd_pcm_mmap_data_fault(struct vm_fault *vmf)
+{
+	struct snd_pcm_substream *substream = vmf->vma->vm_private_data;
+	struct snd_pcm_runtime *runtime;
+	unsigned long offset;
+	struct page * page;
+	size_t dma_bytes;
+	
+	if (substream == NULL)
+		return VM_FAULT_SIGBUS;
+	runtime = substream->runtime;
+	offset = vmf->pgoff << PAGE_SHIFT;
+	dma_bytes = PAGE_ALIGN(runtime->dma_bytes);
+	if (offset > dma_bytes - PAGE_SIZE)
+		return VM_FAULT_SIGBUS;
+	if (substream->ops->page)
+		page = substream->ops->page(substream, offset);
+	else if (!snd_pcm_get_dma_buf(substream))
+		page = virt_to_page(runtime->dma_area + offset);
+	else
+		page = snd_sgbuf_get_page(snd_pcm_get_dma_buf(substream), offset);
+	if (!page)
+		return VM_FAULT_SIGBUS;
+	get_page(page);
+	vmf->page = page;
+	return 0;
+}
+
+static const struct vm_operations_struct snd_pcm_vm_ops_data = {
+	.open =		snd_pcm_mmap_data_open,
+	.close =	snd_pcm_mmap_data_close,
+};
+
+static const struct vm_operations_struct snd_pcm_vm_ops_data_fault = {
+	.open =		snd_pcm_mmap_data_open,
+	.close =	snd_pcm_mmap_data_close,
+	.fault =	snd_pcm_mmap_data_fault,
+};
+
+/*
+ * mmap the DMA buffer on RAM
+ */
+
+/**
+ * snd_pcm_lib_default_mmap - Default PCM data mmap function
+ * @substream: PCM substream
+ * @area: VMA
+ *
+ * This is the default mmap handler for PCM data.  When mmap pcm_ops is NULL,
+ * this function is invoked implicitly.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
+			     struct vm_area_struct *area)
+{
+	vm_flags_set(area, VM_DONTEXPAND | VM_DONTDUMP);
+	if (!substream->ops->page &&
+	    !snd_dma_buffer_mmap(snd_pcm_get_dma_buf(substream), area))
+		return 0;
+	/* mmap with fault handler */
+	area->vm_ops = &snd_pcm_vm_ops_data_fault;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_lib_default_mmap);
+
+/*
+ * mmap the DMA buffer on I/O memory area
+ */
+#if SNDRV_PCM_INFO_MMAP_IOMEM
+/**
+ * snd_pcm_lib_mmap_iomem - Default PCM data mmap function for I/O mem
+ * @substream: PCM substream
+ * @area: VMA
+ *
+ * When your hardware uses the iomapped pages as the hardware buffer and
+ * wants to mmap it, pass this function as mmap pcm_ops.  Note that this
+ * is supposed to work only on limited architectures.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream,
+			   struct vm_area_struct *area)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	area->vm_page_prot = pgprot_noncached(area->vm_page_prot);
+	return vm_iomap_memory(area, runtime->dma_addr, runtime->dma_bytes);
+}
+EXPORT_SYMBOL(snd_pcm_lib_mmap_iomem);
+#endif /* SNDRV_PCM_INFO_MMAP */
+
+/*
+ * mmap DMA buffer
+ */
+int snd_pcm_mmap_data(struct snd_pcm_substream *substream, struct file *file,
+		      struct vm_area_struct *area)
+{
+	struct snd_pcm_runtime *runtime;
+	long size;
+	unsigned long offset;
+	size_t dma_bytes;
+	int err;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		if (!(area->vm_flags & (VM_WRITE|VM_READ)))
+			return -EINVAL;
+	} else {
+		if (!(area->vm_flags & VM_READ))
+			return -EINVAL;
+	}
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_OPEN)
+		return -EBADFD;
+	if (!(runtime->info & SNDRV_PCM_INFO_MMAP))
+		return -ENXIO;
+	if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
+	    runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
+		return -EINVAL;
+	size = area->vm_end - area->vm_start;
+	offset = area->vm_pgoff << PAGE_SHIFT;
+	dma_bytes = PAGE_ALIGN(runtime->dma_bytes);
+	if ((size_t)size > dma_bytes)
+		return -EINVAL;
+	if (offset > dma_bytes - size)
+		return -EINVAL;
+
+	area->vm_ops = &snd_pcm_vm_ops_data;
+	area->vm_private_data = substream;
+	if (substream->ops->mmap)
+		err = substream->ops->mmap(substream, area);
+	else
+		err = snd_pcm_lib_default_mmap(substream, area);
+	if (!err)
+		atomic_inc(&substream->mmap_count);
+	return err;
+}
+EXPORT_SYMBOL(snd_pcm_mmap_data);
+
+static int snd_pcm_mmap(struct file *file, struct vm_area_struct *area)
+{
+	struct snd_pcm_file * pcm_file;
+	struct snd_pcm_substream *substream;	
+	unsigned long offset;
+	
+	pcm_file = file->private_data;
+	substream = pcm_file->substream;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	if (substream->runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+
+	offset = area->vm_pgoff << PAGE_SHIFT;
+	switch (offset) {
+	case SNDRV_PCM_MMAP_OFFSET_STATUS_OLD:
+		if (pcm_file->no_compat_mmap || !IS_ENABLED(CONFIG_64BIT))
+			return -ENXIO;
+		fallthrough;
+	case SNDRV_PCM_MMAP_OFFSET_STATUS_NEW:
+		if (!pcm_status_mmap_allowed(pcm_file))
+			return -ENXIO;
+		return snd_pcm_mmap_status(substream, file, area);
+	case SNDRV_PCM_MMAP_OFFSET_CONTROL_OLD:
+		if (pcm_file->no_compat_mmap || !IS_ENABLED(CONFIG_64BIT))
+			return -ENXIO;
+		fallthrough;
+	case SNDRV_PCM_MMAP_OFFSET_CONTROL_NEW:
+		if (!pcm_control_mmap_allowed(pcm_file))
+			return -ENXIO;
+		return snd_pcm_mmap_control(substream, file, area);
+	default:
+		return snd_pcm_mmap_data(substream, file, area);
+	}
+	return 0;
+}
+
+static int snd_pcm_fasync(int fd, struct file * file, int on)
+{
+	struct snd_pcm_file * pcm_file;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+
+	pcm_file = file->private_data;
+	substream = pcm_file->substream;
+	if (PCM_RUNTIME_CHECK(substream))
+		return -ENXIO;
+	runtime = substream->runtime;
+	if (runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
+		return -EBADFD;
+	return snd_fasync_helper(fd, file, on, &runtime->fasync);
+}
+
+/*
+ * ioctl32 compat
+ */
+#ifdef CONFIG_COMPAT
+#include "pcm_compat.c"
+#else
+#define snd_pcm_ioctl_compat	NULL
+#endif
+
+/*
+ *  To be removed helpers to keep binary compatibility
+ */
+
+#ifdef CONFIG_SND_SUPPORT_OLD_API
+#define __OLD_TO_NEW_MASK(x) ((x&7)|((x&0x07fffff8)<<5))
+#define __NEW_TO_OLD_MASK(x) ((x&7)|((x&0xffffff00)>>5))
+
+static void snd_pcm_hw_convert_from_old_params(struct snd_pcm_hw_params *params,
+					       struct snd_pcm_hw_params_old *oparams)
+{
+	unsigned int i;
+
+	memset(params, 0, sizeof(*params));
+	params->flags = oparams->flags;
+	for (i = 0; i < ARRAY_SIZE(oparams->masks); i++)
+		params->masks[i].bits[0] = oparams->masks[i];
+	memcpy(params->intervals, oparams->intervals, sizeof(oparams->intervals));
+	params->rmask = __OLD_TO_NEW_MASK(oparams->rmask);
+	params->cmask = __OLD_TO_NEW_MASK(oparams->cmask);
+	params->info = oparams->info;
+	params->msbits = oparams->msbits;
+	params->rate_num = oparams->rate_num;
+	params->rate_den = oparams->rate_den;
+	params->fifo_size = oparams->fifo_size;
+}
+
+static void snd_pcm_hw_convert_to_old_params(struct snd_pcm_hw_params_old *oparams,
+					     struct snd_pcm_hw_params *params)
+{
+	unsigned int i;
+
+	memset(oparams, 0, sizeof(*oparams));
+	oparams->flags = params->flags;
+	for (i = 0; i < ARRAY_SIZE(oparams->masks); i++)
+		oparams->masks[i] = params->masks[i].bits[0];
+	memcpy(oparams->intervals, params->intervals, sizeof(oparams->intervals));
+	oparams->rmask = __NEW_TO_OLD_MASK(params->rmask);
+	oparams->cmask = __NEW_TO_OLD_MASK(params->cmask);
+	oparams->info = params->info;
+	oparams->msbits = params->msbits;
+	oparams->rate_num = params->rate_num;
+	oparams->rate_den = params->rate_den;
+	oparams->fifo_size = params->fifo_size;
+}
+
+static int snd_pcm_hw_refine_old_user(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params_old __user * _oparams)
+{
+	struct snd_pcm_hw_params *params;
+	struct snd_pcm_hw_params_old *oparams = NULL;
+	int err;
+
+	params = kmalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+
+	oparams = memdup_user(_oparams, sizeof(*oparams));
+	if (IS_ERR(oparams)) {
+		err = PTR_ERR(oparams);
+		goto out;
+	}
+	snd_pcm_hw_convert_from_old_params(params, oparams);
+	err = snd_pcm_hw_refine(substream, params);
+	if (err < 0)
+		goto out_old;
+
+	err = fixup_unreferenced_params(substream, params);
+	if (err < 0)
+		goto out_old;
+
+	snd_pcm_hw_convert_to_old_params(oparams, params);
+	if (copy_to_user(_oparams, oparams, sizeof(*oparams)))
+		err = -EFAULT;
+out_old:
+	kfree(oparams);
+out:
+	kfree(params);
+	return err;
+}
+
+static int snd_pcm_hw_params_old_user(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params_old __user * _oparams)
+{
+	struct snd_pcm_hw_params *params;
+	struct snd_pcm_hw_params_old *oparams = NULL;
+	int err;
+
+	params = kmalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+
+	oparams = memdup_user(_oparams, sizeof(*oparams));
+	if (IS_ERR(oparams)) {
+		err = PTR_ERR(oparams);
+		goto out;
+	}
+
+	snd_pcm_hw_convert_from_old_params(params, oparams);
+	err = snd_pcm_hw_params(substream, params);
+	if (err < 0)
+		goto out_old;
+
+	snd_pcm_hw_convert_to_old_params(oparams, params);
+	if (copy_to_user(_oparams, oparams, sizeof(*oparams)))
+		err = -EFAULT;
+out_old:
+	kfree(oparams);
+out:
+	kfree(params);
+	return err;
+}
+#endif /* CONFIG_SND_SUPPORT_OLD_API */
+
+#ifndef CONFIG_MMU
+static unsigned long snd_pcm_get_unmapped_area(struct file *file,
+					       unsigned long addr,
+					       unsigned long len,
+					       unsigned long pgoff,
+					       unsigned long flags)
+{
+	struct snd_pcm_file *pcm_file = file->private_data;
+	struct snd_pcm_substream *substream = pcm_file->substream;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	unsigned long offset = pgoff << PAGE_SHIFT;
+
+	switch (offset) {
+	case SNDRV_PCM_MMAP_OFFSET_STATUS_NEW:
+		return (unsigned long)runtime->status;
+	case SNDRV_PCM_MMAP_OFFSET_CONTROL_NEW:
+		return (unsigned long)runtime->control;
+	default:
+		return (unsigned long)runtime->dma_area + offset;
+	}
+}
+#else
+# define snd_pcm_get_unmapped_area NULL
+#endif
+
+/*
+ *  Register section
+ */
+
+const struct file_operations snd_pcm_f_ops[2] = {
+	{
+		.owner =		THIS_MODULE,
+		.write =		snd_pcm_write,
+		.write_iter =		snd_pcm_writev,
+		.open =			snd_pcm_playback_open,
+		.release =		snd_pcm_release,
+		.llseek =		no_llseek,
+		.poll =			snd_pcm_poll,
+		.unlocked_ioctl =	snd_pcm_ioctl,
+		.compat_ioctl = 	snd_pcm_ioctl_compat,
+		.mmap =			snd_pcm_mmap,
+		.fasync =		snd_pcm_fasync,
+		.get_unmapped_area =	snd_pcm_get_unmapped_area,
+	},
+	{
+		.owner =		THIS_MODULE,
+		.read =			snd_pcm_read,
+		.read_iter =		snd_pcm_readv,
+		.open =			snd_pcm_capture_open,
+		.release =		snd_pcm_release,
+		.llseek =		no_llseek,
+		.poll =			snd_pcm_poll,
+		.unlocked_ioctl =	snd_pcm_ioctl,
+		.compat_ioctl = 	snd_pcm_ioctl_compat,
+		.mmap =			snd_pcm_mmap,
+		.fasync =		snd_pcm_fasync,
+		.get_unmapped_area =	snd_pcm_get_unmapped_area,
+	}
+};
diff --git a/sound/core/pcm_param_trace.h b/sound/core/pcm_param_trace.h
new file mode 100644
index 0000000000..08abba3133
--- /dev/null
+++ b/sound/core/pcm_param_trace.h
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM snd_pcm
+
+#if !defined(_PCM_PARAMS_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _PCM_PARAMS_TRACE_H
+
+#include <linux/tracepoint.h>
+
+#define HW_PARAM_ENTRY(param) {SNDRV_PCM_HW_PARAM_##param, #param}
+#define hw_param_labels			\
+	HW_PARAM_ENTRY(ACCESS),		\
+	HW_PARAM_ENTRY(FORMAT),		\
+	HW_PARAM_ENTRY(SUBFORMAT),	\
+	HW_PARAM_ENTRY(SAMPLE_BITS),	\
+	HW_PARAM_ENTRY(FRAME_BITS),	\
+	HW_PARAM_ENTRY(CHANNELS),	\
+	HW_PARAM_ENTRY(RATE),		\
+	HW_PARAM_ENTRY(PERIOD_TIME),	\
+	HW_PARAM_ENTRY(PERIOD_SIZE),	\
+	HW_PARAM_ENTRY(PERIOD_BYTES),	\
+	HW_PARAM_ENTRY(PERIODS),	\
+	HW_PARAM_ENTRY(BUFFER_TIME),	\
+	HW_PARAM_ENTRY(BUFFER_SIZE),	\
+	HW_PARAM_ENTRY(BUFFER_BYTES),	\
+	HW_PARAM_ENTRY(TICK_TIME)
+
+TRACE_EVENT(hw_mask_param,
+	TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_hw_param_t type, int index, const struct snd_mask *prev, const struct snd_mask *curr),
+	TP_ARGS(substream, type, index, prev, curr),
+	TP_STRUCT__entry(
+		__field(int, card)
+		__field(int, device)
+		__field(int, subdevice)
+		__field(int, direction)
+		__field(snd_pcm_hw_param_t, type)
+		__field(int, index)
+		__field(int, total)
+		__array(__u32, prev_bits, 8)
+		__array(__u32, curr_bits, 8)
+	),
+	TP_fast_assign(
+		__entry->card = substream->pcm->card->number;
+		__entry->device = substream->pcm->device;
+		__entry->subdevice = substream->number;
+		__entry->direction = substream->stream;
+		__entry->type = type;
+		__entry->index = index;
+		__entry->total = substream->runtime->hw_constraints.rules_num;
+		memcpy(__entry->prev_bits, prev->bits, sizeof(__u32) * 8);
+		memcpy(__entry->curr_bits, curr->bits, sizeof(__u32) * 8);
+	),
+	TP_printk("pcmC%dD%d%s:%d %03d/%03d %s %08x%08x%08x%08x %08x%08x%08x%08x",
+		  __entry->card,
+		  __entry->device,
+		  __entry->direction ? "c" : "p",
+		  __entry->subdevice,
+		  __entry->index,
+		  __entry->total,
+		  __print_symbolic(__entry->type, hw_param_labels),
+		  __entry->prev_bits[3], __entry->prev_bits[2],
+		  __entry->prev_bits[1], __entry->prev_bits[0],
+		  __entry->curr_bits[3], __entry->curr_bits[2],
+		  __entry->curr_bits[1], __entry->curr_bits[0]
+	)
+);
+
+TRACE_EVENT(hw_interval_param,
+	TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_hw_param_t type, int index, const struct snd_interval *prev, const struct snd_interval *curr),
+	TP_ARGS(substream, type, index, prev, curr),
+	TP_STRUCT__entry(
+		__field(int, card)
+		__field(int, device)
+		__field(int, subdevice)
+		__field(int, direction)
+		__field(snd_pcm_hw_param_t, type)
+		__field(int, index)
+		__field(int, total)
+		__field(unsigned int, prev_min)
+		__field(unsigned int, prev_max)
+		__field(unsigned int, prev_openmin)
+		__field(unsigned int, prev_openmax)
+		__field(unsigned int, prev_integer)
+		__field(unsigned int, prev_empty)
+		__field(unsigned int, curr_min)
+		__field(unsigned int, curr_max)
+		__field(unsigned int, curr_openmin)
+		__field(unsigned int, curr_openmax)
+		__field(unsigned int, curr_integer)
+		__field(unsigned int, curr_empty)
+	),
+	TP_fast_assign(
+		__entry->card = substream->pcm->card->number;
+		__entry->device = substream->pcm->device;
+		__entry->subdevice = substream->number;
+		__entry->direction = substream->stream;
+		__entry->type = type;
+		__entry->index = index;
+		__entry->total = substream->runtime->hw_constraints.rules_num;
+		__entry->prev_min = prev->min;
+		__entry->prev_max = prev->max;
+		__entry->prev_openmin = prev->openmin;
+		__entry->prev_openmax = prev->openmax;
+		__entry->prev_integer = prev->integer;
+		__entry->prev_empty = prev->empty;
+		__entry->curr_min = curr->min;
+		__entry->curr_max = curr->max;
+		__entry->curr_openmin = curr->openmin;
+		__entry->curr_openmax = curr->openmax;
+		__entry->curr_integer = curr->integer;
+		__entry->curr_empty = curr->empty;
+	),
+	TP_printk("pcmC%dD%d%s:%d %03d/%03d %s %d %d %s%u %u%s %d %d %s%u %u%s",
+		  __entry->card,
+		  __entry->device,
+		  __entry->direction ? "c" : "p",
+		  __entry->subdevice,
+		  __entry->index,
+		  __entry->total,
+		  __print_symbolic(__entry->type, hw_param_labels),
+		  __entry->prev_empty,
+		  __entry->prev_integer,
+		  __entry->prev_openmin ? "(" : "[",
+		  __entry->prev_min,
+		  __entry->prev_max,
+		  __entry->prev_openmax ? ")" : "]",
+		  __entry->curr_empty,
+		  __entry->curr_integer,
+		  __entry->curr_openmin ? "(" : "[",
+		  __entry->curr_min,
+		  __entry->curr_max,
+		  __entry->curr_openmax ? ")" : "]"
+	)
+);
+
+#endif /* _PCM_PARAMS_TRACE_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE pcm_param_trace
+#include <trace/define_trace.h>
diff --git a/sound/core/pcm_timer.c b/sound/core/pcm_timer.c
new file mode 100644
index 0000000000..c43484b22b
--- /dev/null
+++ b/sound/core/pcm_timer.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/time.h>
+#include <linux/gcd.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/timer.h>
+
+#include "pcm_local.h"
+
+/*
+ *  Timer functions
+ */
+
+void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream)
+{
+	unsigned long rate, mult, fsize, l, post;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	mult = 1000000000;
+	rate = runtime->rate;
+	if (snd_BUG_ON(!rate))
+		return;
+	l = gcd(mult, rate);
+	mult /= l;
+	rate /= l;
+	fsize = runtime->period_size;
+	if (snd_BUG_ON(!fsize))
+		return;
+	l = gcd(rate, fsize);
+	rate /= l;
+	fsize /= l;
+	post = 1;
+	while ((mult * fsize) / fsize != mult) {
+		mult /= 2;
+		post *= 2;
+	}
+	if (rate == 0) {
+		pcm_err(substream->pcm,
+			"pcm timer resolution out of range (rate = %u, period_size = %lu)\n",
+			runtime->rate, runtime->period_size);
+		runtime->timer_resolution = -1;
+		return;
+	}
+	runtime->timer_resolution = (mult * fsize / rate) * post;
+}
+
+static unsigned long snd_pcm_timer_resolution(struct snd_timer * timer)
+{
+	struct snd_pcm_substream *substream;
+
+	substream = timer->private_data;
+	return substream->runtime ? substream->runtime->timer_resolution : 0;
+}
+
+static int snd_pcm_timer_start(struct snd_timer * timer)
+{
+	struct snd_pcm_substream *substream;
+
+	substream = snd_timer_chip(timer);
+	substream->timer_running = 1;
+	return 0;
+}
+
+static int snd_pcm_timer_stop(struct snd_timer * timer)
+{
+	struct snd_pcm_substream *substream;
+
+	substream = snd_timer_chip(timer);
+	substream->timer_running = 0;
+	return 0;
+}
+
+static const struct snd_timer_hardware snd_pcm_timer =
+{
+	.flags =	SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_SLAVE,
+	.resolution =	0,
+	.ticks =	1,
+	.c_resolution =	snd_pcm_timer_resolution,
+	.start =	snd_pcm_timer_start,
+	.stop =		snd_pcm_timer_stop,
+};
+
+/*
+ *  Init functions
+ */
+
+static void snd_pcm_timer_free(struct snd_timer *timer)
+{
+	struct snd_pcm_substream *substream = timer->private_data;
+	substream->timer = NULL;
+}
+
+void snd_pcm_timer_init(struct snd_pcm_substream *substream)
+{
+	struct snd_timer_id tid;
+	struct snd_timer *timer;
+
+	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	tid.dev_class = SNDRV_TIMER_CLASS_PCM;
+	tid.card = substream->pcm->card->number;
+	tid.device = substream->pcm->device;
+	tid.subdevice = (substream->number << 1) | (substream->stream & 1);
+	if (snd_timer_new(substream->pcm->card, "PCM", &tid, &timer) < 0)
+		return;
+	sprintf(timer->name, "PCM %s %i-%i-%i",
+			substream->stream == SNDRV_PCM_STREAM_CAPTURE ?
+				"capture" : "playback",
+			tid.card, tid.device, tid.subdevice);
+	timer->hw = snd_pcm_timer;
+	if (snd_device_register(timer->card, timer) < 0) {
+		snd_device_free(timer->card, timer);
+		return;
+	}
+	timer->private_data = substream;
+	timer->private_free = snd_pcm_timer_free;
+	substream->timer = timer;
+}
+
+void snd_pcm_timer_done(struct snd_pcm_substream *substream)
+{
+	if (substream->timer) {
+		snd_device_free(substream->pcm->card, substream->timer);
+		substream->timer = NULL;
+	}
+}
diff --git a/sound/core/pcm_trace.h b/sound/core/pcm_trace.h
new file mode 100644
index 0000000000..350b40b906
--- /dev/null
+++ b/sound/core/pcm_trace.h
@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM snd_pcm
+#define TRACE_INCLUDE_FILE pcm_trace
+
+#if !defined(_PCM_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _PCM_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(hwptr,
+	TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_uframes_t pos, bool irq),
+	TP_ARGS(substream, pos, irq),
+	TP_STRUCT__entry(
+		__field( bool, in_interrupt )
+		__field( unsigned int, card )
+		__field( unsigned int, device )
+		__field( unsigned int, number )
+		__field( unsigned int, stream )
+		__field( snd_pcm_uframes_t, pos )
+		__field( snd_pcm_uframes_t, period_size )
+		__field( snd_pcm_uframes_t, buffer_size )
+		__field( snd_pcm_uframes_t, old_hw_ptr )
+		__field( snd_pcm_uframes_t, hw_ptr_base )
+	),
+	TP_fast_assign(
+		__entry->in_interrupt = (irq);
+		__entry->card = (substream)->pcm->card->number;
+		__entry->device = (substream)->pcm->device;
+		__entry->number = (substream)->number;
+		__entry->stream = (substream)->stream;
+		__entry->pos = (pos);
+		__entry->period_size = (substream)->runtime->period_size;
+		__entry->buffer_size = (substream)->runtime->buffer_size;
+		__entry->old_hw_ptr = (substream)->runtime->status->hw_ptr;
+		__entry->hw_ptr_base = (substream)->runtime->hw_ptr_base;
+	),
+	TP_printk("pcmC%dD%d%s/sub%d: %s: pos=%lu, old=%lu, base=%lu, period=%lu, buf=%lu",
+		  __entry->card, __entry->device,
+		  __entry->stream == SNDRV_PCM_STREAM_PLAYBACK ? "p" : "c",
+		  __entry->number,
+		  __entry->in_interrupt ? "IRQ" : "POS",
+		  (unsigned long)__entry->pos,
+		  (unsigned long)__entry->old_hw_ptr,
+		  (unsigned long)__entry->hw_ptr_base,
+		  (unsigned long)__entry->period_size,
+		  (unsigned long)__entry->buffer_size)
+);
+
+TRACE_EVENT(xrun,
+	TP_PROTO(struct snd_pcm_substream *substream),
+	TP_ARGS(substream),
+	TP_STRUCT__entry(
+		__field( unsigned int, card )
+		__field( unsigned int, device )
+		__field( unsigned int, number )
+		__field( unsigned int, stream )
+		__field( snd_pcm_uframes_t, period_size )
+		__field( snd_pcm_uframes_t, buffer_size )
+		__field( snd_pcm_uframes_t, old_hw_ptr )
+		__field( snd_pcm_uframes_t, hw_ptr_base )
+	),
+	TP_fast_assign(
+		__entry->card = (substream)->pcm->card->number;
+		__entry->device = (substream)->pcm->device;
+		__entry->number = (substream)->number;
+		__entry->stream = (substream)->stream;
+		__entry->period_size = (substream)->runtime->period_size;
+		__entry->buffer_size = (substream)->runtime->buffer_size;
+		__entry->old_hw_ptr = (substream)->runtime->status->hw_ptr;
+		__entry->hw_ptr_base = (substream)->runtime->hw_ptr_base;
+	),
+	TP_printk("pcmC%dD%d%s/sub%d: XRUN: old=%lu, base=%lu, period=%lu, buf=%lu",
+		  __entry->card, __entry->device,
+		  __entry->stream == SNDRV_PCM_STREAM_PLAYBACK ? "p" : "c",
+		  __entry->number,
+		  (unsigned long)__entry->old_hw_ptr,
+		  (unsigned long)__entry->hw_ptr_base,
+		  (unsigned long)__entry->period_size,
+		  (unsigned long)__entry->buffer_size)
+);
+
+TRACE_EVENT(hw_ptr_error,
+	TP_PROTO(struct snd_pcm_substream *substream, const char *why),
+	TP_ARGS(substream, why),
+	TP_STRUCT__entry(
+		__field( unsigned int, card )
+		__field( unsigned int, device )
+		__field( unsigned int, number )
+		__field( unsigned int, stream )
+		__string( reason, why )
+	),
+	TP_fast_assign(
+		__entry->card = (substream)->pcm->card->number;
+		__entry->device = (substream)->pcm->device;
+		__entry->number = (substream)->number;
+		__entry->stream = (substream)->stream;
+		__assign_str(reason, why);
+	),
+	TP_printk("pcmC%dD%d%s/sub%d: ERROR: %s",
+		  __entry->card, __entry->device,
+		  __entry->stream == SNDRV_PCM_STREAM_PLAYBACK ? "p" : "c",
+		  __entry->number, __get_str(reason))
+);
+
+TRACE_EVENT(applptr,
+	TP_PROTO(struct snd_pcm_substream *substream, snd_pcm_uframes_t prev, snd_pcm_uframes_t curr),
+	TP_ARGS(substream, prev, curr),
+	TP_STRUCT__entry(
+		__field( unsigned int, card )
+		__field( unsigned int, device )
+		__field( unsigned int, number )
+		__field( unsigned int, stream )
+		__field( snd_pcm_uframes_t, prev )
+		__field( snd_pcm_uframes_t, curr )
+		__field( snd_pcm_uframes_t, avail )
+		__field( snd_pcm_uframes_t, period_size )
+		__field( snd_pcm_uframes_t, buffer_size )
+	),
+	TP_fast_assign(
+		__entry->card = (substream)->pcm->card->number;
+		__entry->device = (substream)->pcm->device;
+		__entry->number = (substream)->number;
+		__entry->stream = (substream)->stream;
+		__entry->prev = (prev);
+		__entry->curr = (curr);
+		__entry->avail = (substream)->stream ? snd_pcm_capture_avail(substream->runtime) : snd_pcm_playback_avail(substream->runtime);
+		__entry->period_size = (substream)->runtime->period_size;
+		__entry->buffer_size = (substream)->runtime->buffer_size;
+	),
+	TP_printk("pcmC%dD%d%s/sub%d: prev=%lu, curr=%lu, avail=%lu, period=%lu, buf=%lu",
+		__entry->card,
+		__entry->device,
+		__entry->stream ? "c" : "p",
+		__entry->number,
+		__entry->prev,
+		__entry->curr,
+		__entry->avail,
+		__entry->period_size,
+		__entry->buffer_size
+	)
+);
+
+#endif /* _PCM_TRACE_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#include <trace/define_trace.h>
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
new file mode 100644
index 0000000000..1431cb9978
--- /dev/null
+++ b/sound/core/rawmidi.c
@@ -0,0 +1,2202 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Abstract layer for MIDI v1.0 stream
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <sound/core.h>
+#include <linux/major.h>
+#include <linux/init.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <linux/nospec.h>
+#include <sound/rawmidi.h>
+#include <sound/info.h>
+#include <sound/control.h>
+#include <sound/minors.h>
+#include <sound/initval.h>
+#include <sound/ump.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Midlevel RawMidi code for ALSA.");
+MODULE_LICENSE("GPL");
+
+#ifdef CONFIG_SND_OSSEMUL
+static int midi_map[SNDRV_CARDS];
+static int amidi_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
+module_param_array(midi_map, int, NULL, 0444);
+MODULE_PARM_DESC(midi_map, "Raw MIDI device number assigned to 1st OSS device.");
+module_param_array(amidi_map, int, NULL, 0444);
+MODULE_PARM_DESC(amidi_map, "Raw MIDI device number assigned to 2nd OSS device.");
+#endif /* CONFIG_SND_OSSEMUL */
+
+static int snd_rawmidi_dev_free(struct snd_device *device);
+static int snd_rawmidi_dev_register(struct snd_device *device);
+static int snd_rawmidi_dev_disconnect(struct snd_device *device);
+
+static LIST_HEAD(snd_rawmidi_devices);
+static DEFINE_MUTEX(register_mutex);
+
+#define rmidi_err(rmidi, fmt, args...) \
+	dev_err((rmidi)->dev, fmt, ##args)
+#define rmidi_warn(rmidi, fmt, args...) \
+	dev_warn((rmidi)->dev, fmt, ##args)
+#define rmidi_dbg(rmidi, fmt, args...) \
+	dev_dbg((rmidi)->dev, fmt, ##args)
+
+struct snd_rawmidi_status32 {
+	s32 stream;
+	s32 tstamp_sec;			/* Timestamp */
+	s32 tstamp_nsec;
+	u32 avail;			/* available bytes */
+	u32 xruns;			/* count of overruns since last status (in bytes) */
+	unsigned char reserved[16];	/* reserved for future use */
+};
+
+#define SNDRV_RAWMIDI_IOCTL_STATUS32	_IOWR('W', 0x20, struct snd_rawmidi_status32)
+
+struct snd_rawmidi_status64 {
+	int stream;
+	u8 rsvd[4];			/* alignment */
+	s64 tstamp_sec;			/* Timestamp */
+	s64 tstamp_nsec;
+	size_t avail;			/* available bytes */
+	size_t xruns;			/* count of overruns since last status (in bytes) */
+	unsigned char reserved[16];	/* reserved for future use */
+};
+
+#define SNDRV_RAWMIDI_IOCTL_STATUS64	_IOWR('W', 0x20, struct snd_rawmidi_status64)
+
+#define rawmidi_is_ump(rmidi) \
+	(IS_ENABLED(CONFIG_SND_UMP) && ((rmidi)->info_flags & SNDRV_RAWMIDI_INFO_UMP))
+
+static struct snd_rawmidi *snd_rawmidi_search(struct snd_card *card, int device)
+{
+	struct snd_rawmidi *rawmidi;
+
+	list_for_each_entry(rawmidi, &snd_rawmidi_devices, list)
+		if (rawmidi->card == card && rawmidi->device == device)
+			return rawmidi;
+	return NULL;
+}
+
+static inline unsigned short snd_rawmidi_file_flags(struct file *file)
+{
+	switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
+	case FMODE_WRITE:
+		return SNDRV_RAWMIDI_LFLG_OUTPUT;
+	case FMODE_READ:
+		return SNDRV_RAWMIDI_LFLG_INPUT;
+	default:
+		return SNDRV_RAWMIDI_LFLG_OPEN;
+	}
+}
+
+static inline bool __snd_rawmidi_ready(struct snd_rawmidi_runtime *runtime)
+{
+	return runtime->avail >= runtime->avail_min;
+}
+
+static bool snd_rawmidi_ready(struct snd_rawmidi_substream *substream)
+{
+	unsigned long flags;
+	bool ready;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	ready = __snd_rawmidi_ready(substream->runtime);
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return ready;
+}
+
+static inline int snd_rawmidi_ready_append(struct snd_rawmidi_substream *substream,
+					   size_t count)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+
+	return runtime->avail >= runtime->avail_min &&
+	       (!substream->append || runtime->avail >= count);
+}
+
+static void snd_rawmidi_input_event_work(struct work_struct *work)
+{
+	struct snd_rawmidi_runtime *runtime =
+		container_of(work, struct snd_rawmidi_runtime, event_work);
+
+	if (runtime->event)
+		runtime->event(runtime->substream);
+}
+
+/* buffer refcount management: call with substream->lock held */
+static inline void snd_rawmidi_buffer_ref(struct snd_rawmidi_runtime *runtime)
+{
+	runtime->buffer_ref++;
+}
+
+static inline void snd_rawmidi_buffer_unref(struct snd_rawmidi_runtime *runtime)
+{
+	runtime->buffer_ref--;
+}
+
+static void snd_rawmidi_buffer_ref_sync(struct snd_rawmidi_substream *substream)
+{
+	int loop = HZ;
+
+	spin_lock_irq(&substream->lock);
+	while (substream->runtime->buffer_ref) {
+		spin_unlock_irq(&substream->lock);
+		if (!--loop) {
+			rmidi_err(substream->rmidi, "Buffer ref sync timeout\n");
+			return;
+		}
+		schedule_timeout_uninterruptible(1);
+		spin_lock_irq(&substream->lock);
+	}
+	spin_unlock_irq(&substream->lock);
+}
+
+static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
+{
+	struct snd_rawmidi_runtime *runtime;
+
+	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
+	if (!runtime)
+		return -ENOMEM;
+	runtime->substream = substream;
+	init_waitqueue_head(&runtime->sleep);
+	INIT_WORK(&runtime->event_work, snd_rawmidi_input_event_work);
+	runtime->event = NULL;
+	runtime->buffer_size = PAGE_SIZE;
+	runtime->avail_min = 1;
+	if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
+		runtime->avail = 0;
+	else
+		runtime->avail = runtime->buffer_size;
+	runtime->buffer = kvzalloc(runtime->buffer_size, GFP_KERNEL);
+	if (!runtime->buffer) {
+		kfree(runtime);
+		return -ENOMEM;
+	}
+	runtime->appl_ptr = runtime->hw_ptr = 0;
+	substream->runtime = runtime;
+	if (rawmidi_is_ump(substream->rmidi))
+		runtime->align = 3;
+	return 0;
+}
+
+/* get the current alignment (either 0 or 3) */
+static inline int get_align(struct snd_rawmidi_runtime *runtime)
+{
+	if (IS_ENABLED(CONFIG_SND_UMP))
+		return runtime->align;
+	else
+		return 0;
+}
+
+/* get the trimmed size with the current alignment */
+#define get_aligned_size(runtime, size) ((size) & ~get_align(runtime))
+
+static int snd_rawmidi_runtime_free(struct snd_rawmidi_substream *substream)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+
+	kvfree(runtime->buffer);
+	kfree(runtime);
+	substream->runtime = NULL;
+	return 0;
+}
+
+static inline void snd_rawmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	if (!substream->opened)
+		return;
+	substream->ops->trigger(substream, up);
+}
+
+static void snd_rawmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	if (!substream->opened)
+		return;
+	substream->ops->trigger(substream, up);
+	if (!up)
+		cancel_work_sync(&substream->runtime->event_work);
+}
+
+static void __reset_runtime_ptrs(struct snd_rawmidi_runtime *runtime,
+				 bool is_input)
+{
+	runtime->drain = 0;
+	runtime->appl_ptr = runtime->hw_ptr = 0;
+	runtime->avail = is_input ? 0 : runtime->buffer_size;
+}
+
+static void reset_runtime_ptrs(struct snd_rawmidi_substream *substream,
+			       bool is_input)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	if (substream->opened && substream->runtime)
+		__reset_runtime_ptrs(substream->runtime, is_input);
+	spin_unlock_irqrestore(&substream->lock, flags);
+}
+
+int snd_rawmidi_drop_output(struct snd_rawmidi_substream *substream)
+{
+	snd_rawmidi_output_trigger(substream, 0);
+	reset_runtime_ptrs(substream, false);
+	return 0;
+}
+EXPORT_SYMBOL(snd_rawmidi_drop_output);
+
+int snd_rawmidi_drain_output(struct snd_rawmidi_substream *substream)
+{
+	int err = 0;
+	long timeout;
+	struct snd_rawmidi_runtime *runtime;
+
+	spin_lock_irq(&substream->lock);
+	runtime = substream->runtime;
+	if (!substream->opened || !runtime || !runtime->buffer) {
+		err = -EINVAL;
+	} else {
+		snd_rawmidi_buffer_ref(runtime);
+		runtime->drain = 1;
+	}
+	spin_unlock_irq(&substream->lock);
+	if (err < 0)
+		return err;
+
+	timeout = wait_event_interruptible_timeout(runtime->sleep,
+				(runtime->avail >= runtime->buffer_size),
+				10*HZ);
+
+	spin_lock_irq(&substream->lock);
+	if (signal_pending(current))
+		err = -ERESTARTSYS;
+	if (runtime->avail < runtime->buffer_size && !timeout) {
+		rmidi_warn(substream->rmidi,
+			   "rawmidi drain error (avail = %li, buffer_size = %li)\n",
+			   (long)runtime->avail, (long)runtime->buffer_size);
+		err = -EIO;
+	}
+	runtime->drain = 0;
+	spin_unlock_irq(&substream->lock);
+
+	if (err != -ERESTARTSYS) {
+		/* we need wait a while to make sure that Tx FIFOs are empty */
+		if (substream->ops->drain)
+			substream->ops->drain(substream);
+		else
+			msleep(50);
+		snd_rawmidi_drop_output(substream);
+	}
+
+	spin_lock_irq(&substream->lock);
+	snd_rawmidi_buffer_unref(runtime);
+	spin_unlock_irq(&substream->lock);
+
+	return err;
+}
+EXPORT_SYMBOL(snd_rawmidi_drain_output);
+
+int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream)
+{
+	snd_rawmidi_input_trigger(substream, 0);
+	reset_runtime_ptrs(substream, true);
+	return 0;
+}
+EXPORT_SYMBOL(snd_rawmidi_drain_input);
+
+/* look for an available substream for the given stream direction;
+ * if a specific subdevice is given, try to assign it
+ */
+static int assign_substream(struct snd_rawmidi *rmidi, int subdevice,
+			    int stream, int mode,
+			    struct snd_rawmidi_substream **sub_ret)
+{
+	struct snd_rawmidi_substream *substream;
+	struct snd_rawmidi_str *s = &rmidi->streams[stream];
+	static const unsigned int info_flags[2] = {
+		[SNDRV_RAWMIDI_STREAM_OUTPUT] = SNDRV_RAWMIDI_INFO_OUTPUT,
+		[SNDRV_RAWMIDI_STREAM_INPUT] = SNDRV_RAWMIDI_INFO_INPUT,
+	};
+
+	if (!(rmidi->info_flags & info_flags[stream]))
+		return -ENXIO;
+	if (subdevice >= 0 && subdevice >= s->substream_count)
+		return -ENODEV;
+
+	list_for_each_entry(substream, &s->substreams, list) {
+		if (substream->opened) {
+			if (stream == SNDRV_RAWMIDI_STREAM_INPUT ||
+			    !(mode & SNDRV_RAWMIDI_LFLG_APPEND) ||
+			    !substream->append)
+				continue;
+		}
+		if (subdevice < 0 || subdevice == substream->number) {
+			*sub_ret = substream;
+			return 0;
+		}
+	}
+	return -EAGAIN;
+}
+
+/* open and do ref-counting for the given substream */
+static int open_substream(struct snd_rawmidi *rmidi,
+			  struct snd_rawmidi_substream *substream,
+			  int mode)
+{
+	int err;
+
+	if (substream->use_count == 0) {
+		err = snd_rawmidi_runtime_create(substream);
+		if (err < 0)
+			return err;
+		err = substream->ops->open(substream);
+		if (err < 0) {
+			snd_rawmidi_runtime_free(substream);
+			return err;
+		}
+		spin_lock_irq(&substream->lock);
+		substream->opened = 1;
+		substream->active_sensing = 0;
+		if (mode & SNDRV_RAWMIDI_LFLG_APPEND)
+			substream->append = 1;
+		substream->pid = get_pid(task_pid(current));
+		rmidi->streams[substream->stream].substream_opened++;
+		spin_unlock_irq(&substream->lock);
+	}
+	substream->use_count++;
+	return 0;
+}
+
+static void close_substream(struct snd_rawmidi *rmidi,
+			    struct snd_rawmidi_substream *substream,
+			    int cleanup);
+
+static int rawmidi_open_priv(struct snd_rawmidi *rmidi, int subdevice, int mode,
+			     struct snd_rawmidi_file *rfile)
+{
+	struct snd_rawmidi_substream *sinput = NULL, *soutput = NULL;
+	int err;
+
+	rfile->input = rfile->output = NULL;
+	if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
+		err = assign_substream(rmidi, subdevice,
+				       SNDRV_RAWMIDI_STREAM_INPUT,
+				       mode, &sinput);
+		if (err < 0)
+			return err;
+	}
+	if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
+		err = assign_substream(rmidi, subdevice,
+				       SNDRV_RAWMIDI_STREAM_OUTPUT,
+				       mode, &soutput);
+		if (err < 0)
+			return err;
+	}
+
+	if (sinput) {
+		err = open_substream(rmidi, sinput, mode);
+		if (err < 0)
+			return err;
+	}
+	if (soutput) {
+		err = open_substream(rmidi, soutput, mode);
+		if (err < 0) {
+			if (sinput)
+				close_substream(rmidi, sinput, 0);
+			return err;
+		}
+	}
+
+	rfile->rmidi = rmidi;
+	rfile->input = sinput;
+	rfile->output = soutput;
+	return 0;
+}
+
+/* called from sound/core/seq/seq_midi.c */
+int snd_rawmidi_kernel_open(struct snd_rawmidi *rmidi, int subdevice,
+			    int mode, struct snd_rawmidi_file *rfile)
+{
+	int err;
+
+	if (snd_BUG_ON(!rfile))
+		return -EINVAL;
+	if (!try_module_get(rmidi->card->module))
+		return -ENXIO;
+
+	mutex_lock(&rmidi->open_mutex);
+	err = rawmidi_open_priv(rmidi, subdevice, mode, rfile);
+	mutex_unlock(&rmidi->open_mutex);
+	if (err < 0)
+		module_put(rmidi->card->module);
+	return err;
+}
+EXPORT_SYMBOL(snd_rawmidi_kernel_open);
+
+static int snd_rawmidi_open(struct inode *inode, struct file *file)
+{
+	int maj = imajor(inode);
+	struct snd_card *card;
+	int subdevice;
+	unsigned short fflags;
+	int err;
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_file *rawmidi_file = NULL;
+	wait_queue_entry_t wait;
+
+	if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK))
+		return -EINVAL;		/* invalid combination */
+
+	err = stream_open(inode, file);
+	if (err < 0)
+		return err;
+
+	if (maj == snd_major) {
+		rmidi = snd_lookup_minor_data(iminor(inode),
+					      SNDRV_DEVICE_TYPE_RAWMIDI);
+#ifdef CONFIG_SND_OSSEMUL
+	} else if (maj == SOUND_MAJOR) {
+		rmidi = snd_lookup_oss_minor_data(iminor(inode),
+						  SNDRV_OSS_DEVICE_TYPE_MIDI);
+#endif
+	} else
+		return -ENXIO;
+
+	if (rmidi == NULL)
+		return -ENODEV;
+
+	if (!try_module_get(rmidi->card->module)) {
+		snd_card_unref(rmidi->card);
+		return -ENXIO;
+	}
+
+	mutex_lock(&rmidi->open_mutex);
+	card = rmidi->card;
+	err = snd_card_file_add(card, file);
+	if (err < 0)
+		goto __error_card;
+	fflags = snd_rawmidi_file_flags(file);
+	if ((file->f_flags & O_APPEND) || maj == SOUND_MAJOR) /* OSS emul? */
+		fflags |= SNDRV_RAWMIDI_LFLG_APPEND;
+	rawmidi_file = kmalloc(sizeof(*rawmidi_file), GFP_KERNEL);
+	if (rawmidi_file == NULL) {
+		err = -ENOMEM;
+		goto __error;
+	}
+	rawmidi_file->user_pversion = 0;
+	init_waitqueue_entry(&wait, current);
+	add_wait_queue(&rmidi->open_wait, &wait);
+	while (1) {
+		subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_RAWMIDI);
+		err = rawmidi_open_priv(rmidi, subdevice, fflags, rawmidi_file);
+		if (err >= 0)
+			break;
+		if (err == -EAGAIN) {
+			if (file->f_flags & O_NONBLOCK) {
+				err = -EBUSY;
+				break;
+			}
+		} else
+			break;
+		set_current_state(TASK_INTERRUPTIBLE);
+		mutex_unlock(&rmidi->open_mutex);
+		schedule();
+		mutex_lock(&rmidi->open_mutex);
+		if (rmidi->card->shutdown) {
+			err = -ENODEV;
+			break;
+		}
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+	}
+	remove_wait_queue(&rmidi->open_wait, &wait);
+	if (err < 0) {
+		kfree(rawmidi_file);
+		goto __error;
+	}
+#ifdef CONFIG_SND_OSSEMUL
+	if (rawmidi_file->input && rawmidi_file->input->runtime)
+		rawmidi_file->input->runtime->oss = (maj == SOUND_MAJOR);
+	if (rawmidi_file->output && rawmidi_file->output->runtime)
+		rawmidi_file->output->runtime->oss = (maj == SOUND_MAJOR);
+#endif
+	file->private_data = rawmidi_file;
+	mutex_unlock(&rmidi->open_mutex);
+	snd_card_unref(rmidi->card);
+	return 0;
+
+ __error:
+	snd_card_file_remove(card, file);
+ __error_card:
+	mutex_unlock(&rmidi->open_mutex);
+	module_put(rmidi->card->module);
+	snd_card_unref(rmidi->card);
+	return err;
+}
+
+static void close_substream(struct snd_rawmidi *rmidi,
+			    struct snd_rawmidi_substream *substream,
+			    int cleanup)
+{
+	if (--substream->use_count)
+		return;
+
+	if (cleanup) {
+		if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
+			snd_rawmidi_input_trigger(substream, 0);
+		else {
+			if (substream->active_sensing) {
+				unsigned char buf = 0xfe;
+				/* sending single active sensing message
+				 * to shut the device up
+				 */
+				snd_rawmidi_kernel_write(substream, &buf, 1);
+			}
+			if (snd_rawmidi_drain_output(substream) == -ERESTARTSYS)
+				snd_rawmidi_output_trigger(substream, 0);
+		}
+		snd_rawmidi_buffer_ref_sync(substream);
+	}
+	spin_lock_irq(&substream->lock);
+	substream->opened = 0;
+	substream->append = 0;
+	spin_unlock_irq(&substream->lock);
+	substream->ops->close(substream);
+	if (substream->runtime->private_free)
+		substream->runtime->private_free(substream);
+	snd_rawmidi_runtime_free(substream);
+	put_pid(substream->pid);
+	substream->pid = NULL;
+	rmidi->streams[substream->stream].substream_opened--;
+}
+
+static void rawmidi_release_priv(struct snd_rawmidi_file *rfile)
+{
+	struct snd_rawmidi *rmidi;
+
+	rmidi = rfile->rmidi;
+	mutex_lock(&rmidi->open_mutex);
+	if (rfile->input) {
+		close_substream(rmidi, rfile->input, 1);
+		rfile->input = NULL;
+	}
+	if (rfile->output) {
+		close_substream(rmidi, rfile->output, 1);
+		rfile->output = NULL;
+	}
+	rfile->rmidi = NULL;
+	mutex_unlock(&rmidi->open_mutex);
+	wake_up(&rmidi->open_wait);
+}
+
+/* called from sound/core/seq/seq_midi.c */
+int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile)
+{
+	struct snd_rawmidi *rmidi;
+
+	if (snd_BUG_ON(!rfile))
+		return -ENXIO;
+
+	rmidi = rfile->rmidi;
+	rawmidi_release_priv(rfile);
+	module_put(rmidi->card->module);
+	return 0;
+}
+EXPORT_SYMBOL(snd_rawmidi_kernel_release);
+
+static int snd_rawmidi_release(struct inode *inode, struct file *file)
+{
+	struct snd_rawmidi_file *rfile;
+	struct snd_rawmidi *rmidi;
+	struct module *module;
+
+	rfile = file->private_data;
+	rmidi = rfile->rmidi;
+	rawmidi_release_priv(rfile);
+	kfree(rfile);
+	module = rmidi->card->module;
+	snd_card_file_remove(rmidi->card, file);
+	module_put(module);
+	return 0;
+}
+
+static int snd_rawmidi_info(struct snd_rawmidi_substream *substream,
+			    struct snd_rawmidi_info *info)
+{
+	struct snd_rawmidi *rmidi;
+
+	if (substream == NULL)
+		return -ENODEV;
+	rmidi = substream->rmidi;
+	memset(info, 0, sizeof(*info));
+	info->card = rmidi->card->number;
+	info->device = rmidi->device;
+	info->subdevice = substream->number;
+	info->stream = substream->stream;
+	info->flags = rmidi->info_flags;
+	strcpy(info->id, rmidi->id);
+	strcpy(info->name, rmidi->name);
+	strcpy(info->subname, substream->name);
+	info->subdevices_count = substream->pstr->substream_count;
+	info->subdevices_avail = (substream->pstr->substream_count -
+				  substream->pstr->substream_opened);
+	return 0;
+}
+
+static int snd_rawmidi_info_user(struct snd_rawmidi_substream *substream,
+				 struct snd_rawmidi_info __user *_info)
+{
+	struct snd_rawmidi_info info;
+	int err;
+
+	err = snd_rawmidi_info(substream, &info);
+	if (err < 0)
+		return err;
+	if (copy_to_user(_info, &info, sizeof(struct snd_rawmidi_info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int __snd_rawmidi_info_select(struct snd_card *card,
+				     struct snd_rawmidi_info *info)
+{
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_str *pstr;
+	struct snd_rawmidi_substream *substream;
+
+	rmidi = snd_rawmidi_search(card, info->device);
+	if (!rmidi)
+		return -ENXIO;
+	if (info->stream < 0 || info->stream > 1)
+		return -EINVAL;
+	info->stream = array_index_nospec(info->stream, 2);
+	pstr = &rmidi->streams[info->stream];
+	if (pstr->substream_count == 0)
+		return -ENOENT;
+	if (info->subdevice >= pstr->substream_count)
+		return -ENXIO;
+	list_for_each_entry(substream, &pstr->substreams, list) {
+		if ((unsigned int)substream->number == info->subdevice)
+			return snd_rawmidi_info(substream, info);
+	}
+	return -ENXIO;
+}
+
+int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info)
+{
+	int ret;
+
+	mutex_lock(&register_mutex);
+	ret = __snd_rawmidi_info_select(card, info);
+	mutex_unlock(&register_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(snd_rawmidi_info_select);
+
+static int snd_rawmidi_info_select_user(struct snd_card *card,
+					struct snd_rawmidi_info __user *_info)
+{
+	int err;
+	struct snd_rawmidi_info info;
+
+	if (get_user(info.device, &_info->device))
+		return -EFAULT;
+	if (get_user(info.stream, &_info->stream))
+		return -EFAULT;
+	if (get_user(info.subdevice, &_info->subdevice))
+		return -EFAULT;
+	err = snd_rawmidi_info_select(card, &info);
+	if (err < 0)
+		return err;
+	if (copy_to_user(_info, &info, sizeof(struct snd_rawmidi_info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int resize_runtime_buffer(struct snd_rawmidi_substream *substream,
+				 struct snd_rawmidi_params *params,
+				 bool is_input)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	char *newbuf, *oldbuf;
+	unsigned int framing = params->mode & SNDRV_RAWMIDI_MODE_FRAMING_MASK;
+
+	if (params->buffer_size < 32 || params->buffer_size > 1024L * 1024L)
+		return -EINVAL;
+	if (framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP && (params->buffer_size & 0x1f) != 0)
+		return -EINVAL;
+	if (params->avail_min < 1 || params->avail_min > params->buffer_size)
+		return -EINVAL;
+	if (params->buffer_size & get_align(runtime))
+		return -EINVAL;
+	if (params->buffer_size != runtime->buffer_size) {
+		newbuf = kvzalloc(params->buffer_size, GFP_KERNEL);
+		if (!newbuf)
+			return -ENOMEM;
+		spin_lock_irq(&substream->lock);
+		if (runtime->buffer_ref) {
+			spin_unlock_irq(&substream->lock);
+			kvfree(newbuf);
+			return -EBUSY;
+		}
+		oldbuf = runtime->buffer;
+		runtime->buffer = newbuf;
+		runtime->buffer_size = params->buffer_size;
+		__reset_runtime_ptrs(runtime, is_input);
+		spin_unlock_irq(&substream->lock);
+		kvfree(oldbuf);
+	}
+	runtime->avail_min = params->avail_min;
+	return 0;
+}
+
+int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream,
+			      struct snd_rawmidi_params *params)
+{
+	int err;
+
+	snd_rawmidi_drain_output(substream);
+	mutex_lock(&substream->rmidi->open_mutex);
+	if (substream->append && substream->use_count > 1)
+		err = -EBUSY;
+	else
+		err = resize_runtime_buffer(substream, params, false);
+
+	if (!err)
+		substream->active_sensing = !params->no_active_sensing;
+	mutex_unlock(&substream->rmidi->open_mutex);
+	return err;
+}
+EXPORT_SYMBOL(snd_rawmidi_output_params);
+
+int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream,
+			     struct snd_rawmidi_params *params)
+{
+	unsigned int framing = params->mode & SNDRV_RAWMIDI_MODE_FRAMING_MASK;
+	unsigned int clock_type = params->mode & SNDRV_RAWMIDI_MODE_CLOCK_MASK;
+	int err;
+
+	snd_rawmidi_drain_input(substream);
+	mutex_lock(&substream->rmidi->open_mutex);
+	if (framing == SNDRV_RAWMIDI_MODE_FRAMING_NONE && clock_type != SNDRV_RAWMIDI_MODE_CLOCK_NONE)
+		err = -EINVAL;
+	else if (clock_type > SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC_RAW)
+		err = -EINVAL;
+	else if (framing > SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP)
+		err = -EINVAL;
+	else
+		err = resize_runtime_buffer(substream, params, true);
+
+	if (!err) {
+		substream->framing = framing;
+		substream->clock_type = clock_type;
+	}
+	mutex_unlock(&substream->rmidi->open_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(snd_rawmidi_input_params);
+
+static int snd_rawmidi_output_status(struct snd_rawmidi_substream *substream,
+				     struct snd_rawmidi_status64 *status)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+
+	memset(status, 0, sizeof(*status));
+	status->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
+	spin_lock_irq(&substream->lock);
+	status->avail = runtime->avail;
+	spin_unlock_irq(&substream->lock);
+	return 0;
+}
+
+static int snd_rawmidi_input_status(struct snd_rawmidi_substream *substream,
+				    struct snd_rawmidi_status64 *status)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+
+	memset(status, 0, sizeof(*status));
+	status->stream = SNDRV_RAWMIDI_STREAM_INPUT;
+	spin_lock_irq(&substream->lock);
+	status->avail = runtime->avail;
+	status->xruns = runtime->xruns;
+	runtime->xruns = 0;
+	spin_unlock_irq(&substream->lock);
+	return 0;
+}
+
+static int snd_rawmidi_ioctl_status32(struct snd_rawmidi_file *rfile,
+				      struct snd_rawmidi_status32 __user *argp)
+{
+	int err = 0;
+	struct snd_rawmidi_status32 __user *status = argp;
+	struct snd_rawmidi_status32 status32;
+	struct snd_rawmidi_status64 status64;
+
+	if (copy_from_user(&status32, argp,
+			   sizeof(struct snd_rawmidi_status32)))
+		return -EFAULT;
+
+	switch (status32.stream) {
+	case SNDRV_RAWMIDI_STREAM_OUTPUT:
+		if (rfile->output == NULL)
+			return -EINVAL;
+		err = snd_rawmidi_output_status(rfile->output, &status64);
+		break;
+	case SNDRV_RAWMIDI_STREAM_INPUT:
+		if (rfile->input == NULL)
+			return -EINVAL;
+		err = snd_rawmidi_input_status(rfile->input, &status64);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	status32 = (struct snd_rawmidi_status32) {
+		.stream = status64.stream,
+		.tstamp_sec = status64.tstamp_sec,
+		.tstamp_nsec = status64.tstamp_nsec,
+		.avail = status64.avail,
+		.xruns = status64.xruns,
+	};
+
+	if (copy_to_user(status, &status32, sizeof(*status)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int snd_rawmidi_ioctl_status64(struct snd_rawmidi_file *rfile,
+				      struct snd_rawmidi_status64 __user *argp)
+{
+	int err = 0;
+	struct snd_rawmidi_status64 status;
+
+	if (copy_from_user(&status, argp, sizeof(struct snd_rawmidi_status64)))
+		return -EFAULT;
+
+	switch (status.stream) {
+	case SNDRV_RAWMIDI_STREAM_OUTPUT:
+		if (rfile->output == NULL)
+			return -EINVAL;
+		err = snd_rawmidi_output_status(rfile->output, &status);
+		break;
+	case SNDRV_RAWMIDI_STREAM_INPUT:
+		if (rfile->input == NULL)
+			return -EINVAL;
+		err = snd_rawmidi_input_status(rfile->input, &status);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+	if (copy_to_user(argp, &status,
+			 sizeof(struct snd_rawmidi_status64)))
+		return -EFAULT;
+	return 0;
+}
+
+static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_rawmidi_file *rfile;
+	struct snd_rawmidi *rmidi;
+	void __user *argp = (void __user *)arg;
+
+	rfile = file->private_data;
+	if (((cmd >> 8) & 0xff) != 'W')
+		return -ENOTTY;
+	switch (cmd) {
+	case SNDRV_RAWMIDI_IOCTL_PVERSION:
+		return put_user(SNDRV_RAWMIDI_VERSION, (int __user *)argp) ? -EFAULT : 0;
+	case SNDRV_RAWMIDI_IOCTL_INFO:
+	{
+		int stream;
+		struct snd_rawmidi_info __user *info = argp;
+
+		if (get_user(stream, &info->stream))
+			return -EFAULT;
+		switch (stream) {
+		case SNDRV_RAWMIDI_STREAM_INPUT:
+			return snd_rawmidi_info_user(rfile->input, info);
+		case SNDRV_RAWMIDI_STREAM_OUTPUT:
+			return snd_rawmidi_info_user(rfile->output, info);
+		default:
+			return -EINVAL;
+		}
+	}
+	case SNDRV_RAWMIDI_IOCTL_USER_PVERSION:
+		if (get_user(rfile->user_pversion, (unsigned int __user *)arg))
+			return -EFAULT;
+		return 0;
+
+	case SNDRV_RAWMIDI_IOCTL_PARAMS:
+	{
+		struct snd_rawmidi_params params;
+
+		if (copy_from_user(&params, argp, sizeof(struct snd_rawmidi_params)))
+			return -EFAULT;
+		if (rfile->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 2)) {
+			params.mode = 0;
+			memset(params.reserved, 0, sizeof(params.reserved));
+		}
+		switch (params.stream) {
+		case SNDRV_RAWMIDI_STREAM_OUTPUT:
+			if (rfile->output == NULL)
+				return -EINVAL;
+			return snd_rawmidi_output_params(rfile->output, &params);
+		case SNDRV_RAWMIDI_STREAM_INPUT:
+			if (rfile->input == NULL)
+				return -EINVAL;
+			return snd_rawmidi_input_params(rfile->input, &params);
+		default:
+			return -EINVAL;
+		}
+	}
+	case SNDRV_RAWMIDI_IOCTL_STATUS32:
+		return snd_rawmidi_ioctl_status32(rfile, argp);
+	case SNDRV_RAWMIDI_IOCTL_STATUS64:
+		return snd_rawmidi_ioctl_status64(rfile, argp);
+	case SNDRV_RAWMIDI_IOCTL_DROP:
+	{
+		int val;
+
+		if (get_user(val, (int __user *) argp))
+			return -EFAULT;
+		switch (val) {
+		case SNDRV_RAWMIDI_STREAM_OUTPUT:
+			if (rfile->output == NULL)
+				return -EINVAL;
+			return snd_rawmidi_drop_output(rfile->output);
+		default:
+			return -EINVAL;
+		}
+	}
+	case SNDRV_RAWMIDI_IOCTL_DRAIN:
+	{
+		int val;
+
+		if (get_user(val, (int __user *) argp))
+			return -EFAULT;
+		switch (val) {
+		case SNDRV_RAWMIDI_STREAM_OUTPUT:
+			if (rfile->output == NULL)
+				return -EINVAL;
+			return snd_rawmidi_drain_output(rfile->output);
+		case SNDRV_RAWMIDI_STREAM_INPUT:
+			if (rfile->input == NULL)
+				return -EINVAL;
+			return snd_rawmidi_drain_input(rfile->input);
+		default:
+			return -EINVAL;
+		}
+	}
+	default:
+		rmidi = rfile->rmidi;
+		if (rmidi->ops && rmidi->ops->ioctl)
+			return rmidi->ops->ioctl(rmidi, cmd, argp);
+		rmidi_dbg(rmidi, "rawmidi: unknown command = 0x%x\n", cmd);
+	}
+	return -ENOTTY;
+}
+
+/* ioctl to find the next device; either legacy or UMP depending on @find_ump */
+static int snd_rawmidi_next_device(struct snd_card *card, int __user *argp,
+				   bool find_ump)
+
+{
+	struct snd_rawmidi *rmidi;
+	int device;
+	bool is_ump;
+
+	if (get_user(device, argp))
+		return -EFAULT;
+	if (device >= SNDRV_RAWMIDI_DEVICES) /* next device is -1 */
+		device = SNDRV_RAWMIDI_DEVICES - 1;
+	mutex_lock(&register_mutex);
+	device = device < 0 ? 0 : device + 1;
+	for (; device < SNDRV_RAWMIDI_DEVICES; device++) {
+		rmidi = snd_rawmidi_search(card, device);
+		if (!rmidi)
+			continue;
+		is_ump = rawmidi_is_ump(rmidi);
+		if (find_ump == is_ump)
+			break;
+	}
+	if (device == SNDRV_RAWMIDI_DEVICES)
+		device = -1;
+	mutex_unlock(&register_mutex);
+	if (put_user(device, argp))
+		return -EFAULT;
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_SND_UMP)
+/* inquiry of UMP endpoint and block info via control API */
+static int snd_rawmidi_call_ump_ioctl(struct snd_card *card, int cmd,
+				      void __user *argp)
+{
+	struct snd_ump_endpoint_info __user *info = argp;
+	struct snd_rawmidi *rmidi;
+	int device, ret;
+
+	if (get_user(device, &info->device))
+		return -EFAULT;
+	mutex_lock(&register_mutex);
+	rmidi = snd_rawmidi_search(card, device);
+	if (rmidi && rmidi->ops && rmidi->ops->ioctl)
+		ret = rmidi->ops->ioctl(rmidi, cmd, argp);
+	else
+		ret = -ENXIO;
+	mutex_unlock(&register_mutex);
+	return ret;
+}
+#endif
+
+static int snd_rawmidi_control_ioctl(struct snd_card *card,
+				     struct snd_ctl_file *control,
+				     unsigned int cmd,
+				     unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE:
+		return snd_rawmidi_next_device(card, argp, false);
+#if IS_ENABLED(CONFIG_SND_UMP)
+	case SNDRV_CTL_IOCTL_UMP_NEXT_DEVICE:
+		return snd_rawmidi_next_device(card, argp, true);
+	case SNDRV_CTL_IOCTL_UMP_ENDPOINT_INFO:
+		return snd_rawmidi_call_ump_ioctl(card, SNDRV_UMP_IOCTL_ENDPOINT_INFO, argp);
+	case SNDRV_CTL_IOCTL_UMP_BLOCK_INFO:
+		return snd_rawmidi_call_ump_ioctl(card, SNDRV_UMP_IOCTL_BLOCK_INFO, argp);
+#endif
+	case SNDRV_CTL_IOCTL_RAWMIDI_PREFER_SUBDEVICE:
+	{
+		int val;
+
+		if (get_user(val, (int __user *)argp))
+			return -EFAULT;
+		control->preferred_subdevice[SND_CTL_SUBDEV_RAWMIDI] = val;
+		return 0;
+	}
+	case SNDRV_CTL_IOCTL_RAWMIDI_INFO:
+		return snd_rawmidi_info_select_user(card, argp);
+	}
+	return -ENOIOCTLCMD;
+}
+
+static int receive_with_tstamp_framing(struct snd_rawmidi_substream *substream,
+			const unsigned char *buffer, int src_count, const struct timespec64 *tstamp)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	struct snd_rawmidi_framing_tstamp *dest_ptr;
+	struct snd_rawmidi_framing_tstamp frame = { .tv_sec = tstamp->tv_sec, .tv_nsec = tstamp->tv_nsec };
+	int orig_count = src_count;
+	int frame_size = sizeof(struct snd_rawmidi_framing_tstamp);
+	int align = get_align(runtime);
+
+	BUILD_BUG_ON(frame_size != 0x20);
+	if (snd_BUG_ON((runtime->hw_ptr & 0x1f) != 0))
+		return -EINVAL;
+
+	while (src_count > align) {
+		if ((int)(runtime->buffer_size - runtime->avail) < frame_size) {
+			runtime->xruns += src_count;
+			break;
+		}
+		if (src_count >= SNDRV_RAWMIDI_FRAMING_DATA_LENGTH)
+			frame.length = SNDRV_RAWMIDI_FRAMING_DATA_LENGTH;
+		else {
+			frame.length = get_aligned_size(runtime, src_count);
+			if (!frame.length)
+				break;
+			memset(frame.data, 0, SNDRV_RAWMIDI_FRAMING_DATA_LENGTH);
+		}
+		memcpy(frame.data, buffer, frame.length);
+		buffer += frame.length;
+		src_count -= frame.length;
+		dest_ptr = (struct snd_rawmidi_framing_tstamp *) (runtime->buffer + runtime->hw_ptr);
+		*dest_ptr = frame;
+		runtime->avail += frame_size;
+		runtime->hw_ptr += frame_size;
+		runtime->hw_ptr %= runtime->buffer_size;
+	}
+	return orig_count - src_count;
+}
+
+static struct timespec64 get_framing_tstamp(struct snd_rawmidi_substream *substream)
+{
+	struct timespec64 ts64 = {0, 0};
+
+	switch (substream->clock_type) {
+	case SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC_RAW:
+		ktime_get_raw_ts64(&ts64);
+		break;
+	case SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC:
+		ktime_get_ts64(&ts64);
+		break;
+	case SNDRV_RAWMIDI_MODE_CLOCK_REALTIME:
+		ktime_get_real_ts64(&ts64);
+		break;
+	}
+	return ts64;
+}
+
+/**
+ * snd_rawmidi_receive - receive the input data from the device
+ * @substream: the rawmidi substream
+ * @buffer: the buffer pointer
+ * @count: the data size to read
+ *
+ * Reads the data from the internal buffer.
+ *
+ * Return: The size of read data, or a negative error code on failure.
+ */
+int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
+			const unsigned char *buffer, int count)
+{
+	unsigned long flags;
+	struct timespec64 ts64 = get_framing_tstamp(substream);
+	int result = 0, count1;
+	struct snd_rawmidi_runtime *runtime;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	if (!substream->opened) {
+		result = -EBADFD;
+		goto unlock;
+	}
+	runtime = substream->runtime;
+	if (!runtime || !runtime->buffer) {
+		rmidi_dbg(substream->rmidi,
+			  "snd_rawmidi_receive: input is not active!!!\n");
+		result = -EINVAL;
+		goto unlock;
+	}
+
+	count = get_aligned_size(runtime, count);
+	if (!count)
+		goto unlock;
+
+	if (substream->framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP) {
+		result = receive_with_tstamp_framing(substream, buffer, count, &ts64);
+	} else if (count == 1) {	/* special case, faster code */
+		substream->bytes++;
+		if (runtime->avail < runtime->buffer_size) {
+			runtime->buffer[runtime->hw_ptr++] = buffer[0];
+			runtime->hw_ptr %= runtime->buffer_size;
+			runtime->avail++;
+			result++;
+		} else {
+			runtime->xruns++;
+		}
+	} else {
+		substream->bytes += count;
+		count1 = runtime->buffer_size - runtime->hw_ptr;
+		if (count1 > count)
+			count1 = count;
+		if (count1 > (int)(runtime->buffer_size - runtime->avail))
+			count1 = runtime->buffer_size - runtime->avail;
+		count1 = get_aligned_size(runtime, count1);
+		if (!count1)
+			goto unlock;
+		memcpy(runtime->buffer + runtime->hw_ptr, buffer, count1);
+		runtime->hw_ptr += count1;
+		runtime->hw_ptr %= runtime->buffer_size;
+		runtime->avail += count1;
+		count -= count1;
+		result += count1;
+		if (count > 0) {
+			buffer += count1;
+			count1 = count;
+			if (count1 > (int)(runtime->buffer_size - runtime->avail)) {
+				count1 = runtime->buffer_size - runtime->avail;
+				runtime->xruns += count - count1;
+			}
+			if (count1 > 0) {
+				memcpy(runtime->buffer, buffer, count1);
+				runtime->hw_ptr = count1;
+				runtime->avail += count1;
+				result += count1;
+			}
+		}
+	}
+	if (result > 0) {
+		if (runtime->event)
+			schedule_work(&runtime->event_work);
+		else if (__snd_rawmidi_ready(runtime))
+			wake_up(&runtime->sleep);
+	}
+ unlock:
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return result;
+}
+EXPORT_SYMBOL(snd_rawmidi_receive);
+
+static long snd_rawmidi_kernel_read1(struct snd_rawmidi_substream *substream,
+				     unsigned char __user *userbuf,
+				     unsigned char *kernelbuf, long count)
+{
+	unsigned long flags;
+	long result = 0, count1;
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	unsigned long appl_ptr;
+	int err = 0;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	snd_rawmidi_buffer_ref(runtime);
+	while (count > 0 && runtime->avail) {
+		count1 = runtime->buffer_size - runtime->appl_ptr;
+		if (count1 > count)
+			count1 = count;
+		if (count1 > (int)runtime->avail)
+			count1 = runtime->avail;
+
+		/* update runtime->appl_ptr before unlocking for userbuf */
+		appl_ptr = runtime->appl_ptr;
+		runtime->appl_ptr += count1;
+		runtime->appl_ptr %= runtime->buffer_size;
+		runtime->avail -= count1;
+
+		if (kernelbuf)
+			memcpy(kernelbuf + result, runtime->buffer + appl_ptr, count1);
+		if (userbuf) {
+			spin_unlock_irqrestore(&substream->lock, flags);
+			if (copy_to_user(userbuf + result,
+					 runtime->buffer + appl_ptr, count1))
+				err = -EFAULT;
+			spin_lock_irqsave(&substream->lock, flags);
+			if (err)
+				goto out;
+		}
+		result += count1;
+		count -= count1;
+	}
+ out:
+	snd_rawmidi_buffer_unref(runtime);
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return result > 0 ? result : err;
+}
+
+long snd_rawmidi_kernel_read(struct snd_rawmidi_substream *substream,
+			     unsigned char *buf, long count)
+{
+	snd_rawmidi_input_trigger(substream, 1);
+	return snd_rawmidi_kernel_read1(substream, NULL/*userbuf*/, buf, count);
+}
+EXPORT_SYMBOL(snd_rawmidi_kernel_read);
+
+static ssize_t snd_rawmidi_read(struct file *file, char __user *buf, size_t count,
+				loff_t *offset)
+{
+	long result;
+	int count1;
+	struct snd_rawmidi_file *rfile;
+	struct snd_rawmidi_substream *substream;
+	struct snd_rawmidi_runtime *runtime;
+
+	rfile = file->private_data;
+	substream = rfile->input;
+	if (substream == NULL)
+		return -EIO;
+	runtime = substream->runtime;
+	snd_rawmidi_input_trigger(substream, 1);
+	result = 0;
+	while (count > 0) {
+		spin_lock_irq(&substream->lock);
+		while (!__snd_rawmidi_ready(runtime)) {
+			wait_queue_entry_t wait;
+
+			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
+				spin_unlock_irq(&substream->lock);
+				return result > 0 ? result : -EAGAIN;
+			}
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&runtime->sleep, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+			spin_unlock_irq(&substream->lock);
+			schedule();
+			remove_wait_queue(&runtime->sleep, &wait);
+			if (rfile->rmidi->card->shutdown)
+				return -ENODEV;
+			if (signal_pending(current))
+				return result > 0 ? result : -ERESTARTSYS;
+			spin_lock_irq(&substream->lock);
+			if (!runtime->avail) {
+				spin_unlock_irq(&substream->lock);
+				return result > 0 ? result : -EIO;
+			}
+		}
+		spin_unlock_irq(&substream->lock);
+		count1 = snd_rawmidi_kernel_read1(substream,
+						  (unsigned char __user *)buf,
+						  NULL/*kernelbuf*/,
+						  count);
+		if (count1 < 0)
+			return result > 0 ? result : count1;
+		result += count1;
+		buf += count1;
+		count -= count1;
+	}
+	return result;
+}
+
+/**
+ * snd_rawmidi_transmit_empty - check whether the output buffer is empty
+ * @substream: the rawmidi substream
+ *
+ * Return: 1 if the internal output buffer is empty, 0 if not.
+ */
+int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream)
+{
+	struct snd_rawmidi_runtime *runtime;
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	runtime = substream->runtime;
+	if (!substream->opened || !runtime || !runtime->buffer) {
+		rmidi_dbg(substream->rmidi,
+			  "snd_rawmidi_transmit_empty: output is not active!!!\n");
+		result = 1;
+	} else {
+		result = runtime->avail >= runtime->buffer_size;
+	}
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return result;
+}
+EXPORT_SYMBOL(snd_rawmidi_transmit_empty);
+
+/*
+ * __snd_rawmidi_transmit_peek - copy data from the internal buffer
+ * @substream: the rawmidi substream
+ * @buffer: the buffer pointer
+ * @count: data size to transfer
+ *
+ * This is a variant of snd_rawmidi_transmit_peek() without spinlock.
+ */
+static int __snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
+				       unsigned char *buffer, int count)
+{
+	int result, count1;
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+
+	if (runtime->buffer == NULL) {
+		rmidi_dbg(substream->rmidi,
+			  "snd_rawmidi_transmit_peek: output is not active!!!\n");
+		return -EINVAL;
+	}
+	result = 0;
+	if (runtime->avail >= runtime->buffer_size) {
+		/* warning: lowlevel layer MUST trigger down the hardware */
+		goto __skip;
+	}
+	if (count == 1) {	/* special case, faster code */
+		*buffer = runtime->buffer[runtime->hw_ptr];
+		result++;
+	} else {
+		count1 = runtime->buffer_size - runtime->hw_ptr;
+		if (count1 > count)
+			count1 = count;
+		if (count1 > (int)(runtime->buffer_size - runtime->avail))
+			count1 = runtime->buffer_size - runtime->avail;
+		count1 = get_aligned_size(runtime, count1);
+		if (!count1)
+			goto __skip;
+		memcpy(buffer, runtime->buffer + runtime->hw_ptr, count1);
+		count -= count1;
+		result += count1;
+		if (count > 0) {
+			if (count > (int)(runtime->buffer_size - runtime->avail - count1))
+				count = runtime->buffer_size - runtime->avail - count1;
+			count = get_aligned_size(runtime, count);
+			if (!count)
+				goto __skip;
+			memcpy(buffer + count1, runtime->buffer, count);
+			result += count;
+		}
+	}
+      __skip:
+	return result;
+}
+
+/**
+ * snd_rawmidi_transmit_peek - copy data from the internal buffer
+ * @substream: the rawmidi substream
+ * @buffer: the buffer pointer
+ * @count: data size to transfer
+ *
+ * Copies data from the internal output buffer to the given buffer.
+ *
+ * Call this in the interrupt handler when the midi output is ready,
+ * and call snd_rawmidi_transmit_ack() after the transmission is
+ * finished.
+ *
+ * Return: The size of copied data, or a negative error code on failure.
+ */
+int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
+			      unsigned char *buffer, int count)
+{
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	if (!substream->opened || !substream->runtime)
+		result = -EBADFD;
+	else
+		result = __snd_rawmidi_transmit_peek(substream, buffer, count);
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return result;
+}
+EXPORT_SYMBOL(snd_rawmidi_transmit_peek);
+
+/*
+ * __snd_rawmidi_transmit_ack - acknowledge the transmission
+ * @substream: the rawmidi substream
+ * @count: the transferred count
+ *
+ * This is a variant of __snd_rawmidi_transmit_ack() without spinlock.
+ */
+static int __snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream,
+				      int count)
+{
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+
+	if (runtime->buffer == NULL) {
+		rmidi_dbg(substream->rmidi,
+			  "snd_rawmidi_transmit_ack: output is not active!!!\n");
+		return -EINVAL;
+	}
+	snd_BUG_ON(runtime->avail + count > runtime->buffer_size);
+	count = get_aligned_size(runtime, count);
+	runtime->hw_ptr += count;
+	runtime->hw_ptr %= runtime->buffer_size;
+	runtime->avail += count;
+	substream->bytes += count;
+	if (count > 0) {
+		if (runtime->drain || __snd_rawmidi_ready(runtime))
+			wake_up(&runtime->sleep);
+	}
+	return count;
+}
+
+/**
+ * snd_rawmidi_transmit_ack - acknowledge the transmission
+ * @substream: the rawmidi substream
+ * @count: the transferred count
+ *
+ * Advances the hardware pointer for the internal output buffer with
+ * the given size and updates the condition.
+ * Call after the transmission is finished.
+ *
+ * Return: The advanced size if successful, or a negative error code on failure.
+ */
+int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
+{
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	if (!substream->opened || !substream->runtime)
+		result = -EBADFD;
+	else
+		result = __snd_rawmidi_transmit_ack(substream, count);
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return result;
+}
+EXPORT_SYMBOL(snd_rawmidi_transmit_ack);
+
+/**
+ * snd_rawmidi_transmit - copy from the buffer to the device
+ * @substream: the rawmidi substream
+ * @buffer: the buffer pointer
+ * @count: the data size to transfer
+ *
+ * Copies data from the buffer to the device and advances the pointer.
+ *
+ * Return: The copied size if successful, or a negative error code on failure.
+ */
+int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream,
+			 unsigned char *buffer, int count)
+{
+	int result;
+	unsigned long flags;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	if (!substream->opened)
+		result = -EBADFD;
+	else {
+		count = __snd_rawmidi_transmit_peek(substream, buffer, count);
+		if (count <= 0)
+			result = count;
+		else
+			result = __snd_rawmidi_transmit_ack(substream, count);
+	}
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return result;
+}
+EXPORT_SYMBOL(snd_rawmidi_transmit);
+
+/**
+ * snd_rawmidi_proceed - Discard the all pending bytes and proceed
+ * @substream: rawmidi substream
+ *
+ * Return: the number of discarded bytes
+ */
+int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream)
+{
+	struct snd_rawmidi_runtime *runtime;
+	unsigned long flags;
+	int count = 0;
+
+	spin_lock_irqsave(&substream->lock, flags);
+	runtime = substream->runtime;
+	if (substream->opened && runtime &&
+	    runtime->avail < runtime->buffer_size) {
+		count = runtime->buffer_size - runtime->avail;
+		__snd_rawmidi_transmit_ack(substream, count);
+	}
+	spin_unlock_irqrestore(&substream->lock, flags);
+	return count;
+}
+EXPORT_SYMBOL(snd_rawmidi_proceed);
+
+static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
+				      const unsigned char __user *userbuf,
+				      const unsigned char *kernelbuf,
+				      long count)
+{
+	unsigned long flags;
+	long count1, result;
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	unsigned long appl_ptr;
+
+	if (!kernelbuf && !userbuf)
+		return -EINVAL;
+	if (snd_BUG_ON(!runtime->buffer))
+		return -EINVAL;
+
+	result = 0;
+	spin_lock_irqsave(&substream->lock, flags);
+	if (substream->append) {
+		if ((long)runtime->avail < count) {
+			spin_unlock_irqrestore(&substream->lock, flags);
+			return -EAGAIN;
+		}
+	}
+	snd_rawmidi_buffer_ref(runtime);
+	while (count > 0 && runtime->avail > 0) {
+		count1 = runtime->buffer_size - runtime->appl_ptr;
+		if (count1 > count)
+			count1 = count;
+		if (count1 > (long)runtime->avail)
+			count1 = runtime->avail;
+
+		/* update runtime->appl_ptr before unlocking for userbuf */
+		appl_ptr = runtime->appl_ptr;
+		runtime->appl_ptr += count1;
+		runtime->appl_ptr %= runtime->buffer_size;
+		runtime->avail -= count1;
+
+		if (kernelbuf)
+			memcpy(runtime->buffer + appl_ptr,
+			       kernelbuf + result, count1);
+		else if (userbuf) {
+			spin_unlock_irqrestore(&substream->lock, flags);
+			if (copy_from_user(runtime->buffer + appl_ptr,
+					   userbuf + result, count1)) {
+				spin_lock_irqsave(&substream->lock, flags);
+				result = result > 0 ? result : -EFAULT;
+				goto __end;
+			}
+			spin_lock_irqsave(&substream->lock, flags);
+		}
+		result += count1;
+		count -= count1;
+	}
+      __end:
+	count1 = runtime->avail < runtime->buffer_size;
+	snd_rawmidi_buffer_unref(runtime);
+	spin_unlock_irqrestore(&substream->lock, flags);
+	if (count1)
+		snd_rawmidi_output_trigger(substream, 1);
+	return result;
+}
+
+long snd_rawmidi_kernel_write(struct snd_rawmidi_substream *substream,
+			      const unsigned char *buf, long count)
+{
+	return snd_rawmidi_kernel_write1(substream, NULL, buf, count);
+}
+EXPORT_SYMBOL(snd_rawmidi_kernel_write);
+
+static ssize_t snd_rawmidi_write(struct file *file, const char __user *buf,
+				 size_t count, loff_t *offset)
+{
+	long result, timeout;
+	int count1;
+	struct snd_rawmidi_file *rfile;
+	struct snd_rawmidi_runtime *runtime;
+	struct snd_rawmidi_substream *substream;
+
+	rfile = file->private_data;
+	substream = rfile->output;
+	runtime = substream->runtime;
+	/* we cannot put an atomic message to our buffer */
+	if (substream->append && count > runtime->buffer_size)
+		return -EIO;
+	result = 0;
+	while (count > 0) {
+		spin_lock_irq(&substream->lock);
+		while (!snd_rawmidi_ready_append(substream, count)) {
+			wait_queue_entry_t wait;
+
+			if (file->f_flags & O_NONBLOCK) {
+				spin_unlock_irq(&substream->lock);
+				return result > 0 ? result : -EAGAIN;
+			}
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&runtime->sleep, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+			spin_unlock_irq(&substream->lock);
+			timeout = schedule_timeout(30 * HZ);
+			remove_wait_queue(&runtime->sleep, &wait);
+			if (rfile->rmidi->card->shutdown)
+				return -ENODEV;
+			if (signal_pending(current))
+				return result > 0 ? result : -ERESTARTSYS;
+			spin_lock_irq(&substream->lock);
+			if (!runtime->avail && !timeout) {
+				spin_unlock_irq(&substream->lock);
+				return result > 0 ? result : -EIO;
+			}
+		}
+		spin_unlock_irq(&substream->lock);
+		count1 = snd_rawmidi_kernel_write1(substream, buf, NULL, count);
+		if (count1 < 0)
+			return result > 0 ? result : count1;
+		result += count1;
+		buf += count1;
+		if ((size_t)count1 < count && (file->f_flags & O_NONBLOCK))
+			break;
+		count -= count1;
+	}
+	if (file->f_flags & O_DSYNC) {
+		spin_lock_irq(&substream->lock);
+		while (runtime->avail != runtime->buffer_size) {
+			wait_queue_entry_t wait;
+			unsigned int last_avail = runtime->avail;
+
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&runtime->sleep, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+			spin_unlock_irq(&substream->lock);
+			timeout = schedule_timeout(30 * HZ);
+			remove_wait_queue(&runtime->sleep, &wait);
+			if (signal_pending(current))
+				return result > 0 ? result : -ERESTARTSYS;
+			if (runtime->avail == last_avail && !timeout)
+				return result > 0 ? result : -EIO;
+			spin_lock_irq(&substream->lock);
+		}
+		spin_unlock_irq(&substream->lock);
+	}
+	return result;
+}
+
+static __poll_t snd_rawmidi_poll(struct file *file, poll_table *wait)
+{
+	struct snd_rawmidi_file *rfile;
+	struct snd_rawmidi_runtime *runtime;
+	__poll_t mask;
+
+	rfile = file->private_data;
+	if (rfile->input != NULL) {
+		runtime = rfile->input->runtime;
+		snd_rawmidi_input_trigger(rfile->input, 1);
+		poll_wait(file, &runtime->sleep, wait);
+	}
+	if (rfile->output != NULL) {
+		runtime = rfile->output->runtime;
+		poll_wait(file, &runtime->sleep, wait);
+	}
+	mask = 0;
+	if (rfile->input != NULL) {
+		if (snd_rawmidi_ready(rfile->input))
+			mask |= EPOLLIN | EPOLLRDNORM;
+	}
+	if (rfile->output != NULL) {
+		if (snd_rawmidi_ready(rfile->output))
+			mask |= EPOLLOUT | EPOLLWRNORM;
+	}
+	return mask;
+}
+
+/*
+ */
+#ifdef CONFIG_COMPAT
+#include "rawmidi_compat.c"
+#else
+#define snd_rawmidi_ioctl_compat	NULL
+#endif
+
+/*
+ */
+
+static void snd_rawmidi_proc_info_read(struct snd_info_entry *entry,
+				       struct snd_info_buffer *buffer)
+{
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_substream *substream;
+	struct snd_rawmidi_runtime *runtime;
+	unsigned long buffer_size, avail, xruns;
+	unsigned int clock_type;
+	static const char *clock_names[4] = { "none", "realtime", "monotonic", "monotonic raw" };
+
+	rmidi = entry->private_data;
+	snd_iprintf(buffer, "%s\n\n", rmidi->name);
+	if (IS_ENABLED(CONFIG_SND_UMP))
+		snd_iprintf(buffer, "Type: %s\n",
+			    rawmidi_is_ump(rmidi) ? "UMP" : "Legacy");
+	if (rmidi->ops && rmidi->ops->proc_read)
+		rmidi->ops->proc_read(entry, buffer);
+	mutex_lock(&rmidi->open_mutex);
+	if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT) {
+		list_for_each_entry(substream,
+				    &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
+				    list) {
+			snd_iprintf(buffer,
+				    "Output %d\n"
+				    "  Tx bytes     : %lu\n",
+				    substream->number,
+				    (unsigned long) substream->bytes);
+			if (substream->opened) {
+				snd_iprintf(buffer,
+				    "  Owner PID    : %d\n",
+				    pid_vnr(substream->pid));
+				runtime = substream->runtime;
+				spin_lock_irq(&substream->lock);
+				buffer_size = runtime->buffer_size;
+				avail = runtime->avail;
+				spin_unlock_irq(&substream->lock);
+				snd_iprintf(buffer,
+				    "  Mode         : %s\n"
+				    "  Buffer size  : %lu\n"
+				    "  Avail        : %lu\n",
+				    runtime->oss ? "OSS compatible" : "native",
+				    buffer_size, avail);
+			}
+		}
+	}
+	if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_INPUT) {
+		list_for_each_entry(substream,
+				    &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams,
+				    list) {
+			snd_iprintf(buffer,
+				    "Input %d\n"
+				    "  Rx bytes     : %lu\n",
+				    substream->number,
+				    (unsigned long) substream->bytes);
+			if (substream->opened) {
+				snd_iprintf(buffer,
+					    "  Owner PID    : %d\n",
+					    pid_vnr(substream->pid));
+				runtime = substream->runtime;
+				spin_lock_irq(&substream->lock);
+				buffer_size = runtime->buffer_size;
+				avail = runtime->avail;
+				xruns = runtime->xruns;
+				spin_unlock_irq(&substream->lock);
+				snd_iprintf(buffer,
+					    "  Buffer size  : %lu\n"
+					    "  Avail        : %lu\n"
+					    "  Overruns     : %lu\n",
+					    buffer_size, avail, xruns);
+				if (substream->framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP) {
+					clock_type = substream->clock_type >> SNDRV_RAWMIDI_MODE_CLOCK_SHIFT;
+					if (!snd_BUG_ON(clock_type >= ARRAY_SIZE(clock_names)))
+						snd_iprintf(buffer,
+							    "  Framing      : tstamp\n"
+							    "  Clock type   : %s\n",
+							    clock_names[clock_type]);
+				}
+			}
+		}
+	}
+	mutex_unlock(&rmidi->open_mutex);
+}
+
+/*
+ *  Register functions
+ */
+
+static const struct file_operations snd_rawmidi_f_ops = {
+	.owner =	THIS_MODULE,
+	.read =		snd_rawmidi_read,
+	.write =	snd_rawmidi_write,
+	.open =		snd_rawmidi_open,
+	.release =	snd_rawmidi_release,
+	.llseek =	no_llseek,
+	.poll =		snd_rawmidi_poll,
+	.unlocked_ioctl =	snd_rawmidi_ioctl,
+	.compat_ioctl =	snd_rawmidi_ioctl_compat,
+};
+
+static int snd_rawmidi_alloc_substreams(struct snd_rawmidi *rmidi,
+					struct snd_rawmidi_str *stream,
+					int direction,
+					int count)
+{
+	struct snd_rawmidi_substream *substream;
+	int idx;
+
+	for (idx = 0; idx < count; idx++) {
+		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
+		if (!substream)
+			return -ENOMEM;
+		substream->stream = direction;
+		substream->number = idx;
+		substream->rmidi = rmidi;
+		substream->pstr = stream;
+		spin_lock_init(&substream->lock);
+		list_add_tail(&substream->list, &stream->substreams);
+		stream->substream_count++;
+	}
+	return 0;
+}
+
+/* used for both rawmidi and ump */
+int snd_rawmidi_init(struct snd_rawmidi *rmidi,
+		     struct snd_card *card, char *id, int device,
+		     int output_count, int input_count,
+		     unsigned int info_flags)
+{
+	int err;
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_rawmidi_dev_free,
+		.dev_register = snd_rawmidi_dev_register,
+		.dev_disconnect = snd_rawmidi_dev_disconnect,
+	};
+
+	rmidi->card = card;
+	rmidi->device = device;
+	mutex_init(&rmidi->open_mutex);
+	init_waitqueue_head(&rmidi->open_wait);
+	INIT_LIST_HEAD(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams);
+	INIT_LIST_HEAD(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams);
+	rmidi->info_flags = info_flags;
+
+	if (id != NULL)
+		strscpy(rmidi->id, id, sizeof(rmidi->id));
+
+	err = snd_device_alloc(&rmidi->dev, card);
+	if (err < 0)
+		return err;
+	if (rawmidi_is_ump(rmidi))
+		dev_set_name(rmidi->dev, "umpC%iD%i", card->number, device);
+	else
+		dev_set_name(rmidi->dev, "midiC%iD%i", card->number, device);
+
+	err = snd_rawmidi_alloc_substreams(rmidi,
+					   &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT],
+					   SNDRV_RAWMIDI_STREAM_INPUT,
+					   input_count);
+	if (err < 0)
+		return err;
+	err = snd_rawmidi_alloc_substreams(rmidi,
+					   &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT],
+					   SNDRV_RAWMIDI_STREAM_OUTPUT,
+					   output_count);
+	if (err < 0)
+		return err;
+	err = snd_device_new(card, SNDRV_DEV_RAWMIDI, rmidi, &ops);
+	if (err < 0)
+		return err;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_rawmidi_init);
+
+/**
+ * snd_rawmidi_new - create a rawmidi instance
+ * @card: the card instance
+ * @id: the id string
+ * @device: the device index
+ * @output_count: the number of output streams
+ * @input_count: the number of input streams
+ * @rrawmidi: the pointer to store the new rawmidi instance
+ *
+ * Creates a new rawmidi instance.
+ * Use snd_rawmidi_set_ops() to set the operators to the new instance.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_rawmidi_new(struct snd_card *card, char *id, int device,
+		    int output_count, int input_count,
+		    struct snd_rawmidi **rrawmidi)
+{
+	struct snd_rawmidi *rmidi;
+	int err;
+
+	if (rrawmidi)
+		*rrawmidi = NULL;
+	rmidi = kzalloc(sizeof(*rmidi), GFP_KERNEL);
+	if (!rmidi)
+		return -ENOMEM;
+	err = snd_rawmidi_init(rmidi, card, id, device,
+			       output_count, input_count, 0);
+	if (err < 0) {
+		snd_rawmidi_free(rmidi);
+		return err;
+	}
+	if (rrawmidi)
+		*rrawmidi = rmidi;
+	return 0;
+}
+EXPORT_SYMBOL(snd_rawmidi_new);
+
+static void snd_rawmidi_free_substreams(struct snd_rawmidi_str *stream)
+{
+	struct snd_rawmidi_substream *substream;
+
+	while (!list_empty(&stream->substreams)) {
+		substream = list_entry(stream->substreams.next, struct snd_rawmidi_substream, list);
+		list_del(&substream->list);
+		kfree(substream);
+	}
+}
+
+/* called from ump.c, too */
+int snd_rawmidi_free(struct snd_rawmidi *rmidi)
+{
+	if (!rmidi)
+		return 0;
+
+	snd_info_free_entry(rmidi->proc_entry);
+	rmidi->proc_entry = NULL;
+	if (rmidi->ops && rmidi->ops->dev_unregister)
+		rmidi->ops->dev_unregister(rmidi);
+
+	snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
+	snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
+	if (rmidi->private_free)
+		rmidi->private_free(rmidi);
+	put_device(rmidi->dev);
+	kfree(rmidi);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_rawmidi_free);
+
+static int snd_rawmidi_dev_free(struct snd_device *device)
+{
+	struct snd_rawmidi *rmidi = device->device_data;
+
+	return snd_rawmidi_free(rmidi);
+}
+
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+static void snd_rawmidi_dev_seq_free(struct snd_seq_device *device)
+{
+	struct snd_rawmidi *rmidi = device->private_data;
+
+	rmidi->seq_dev = NULL;
+}
+#endif
+
+static int snd_rawmidi_dev_register(struct snd_device *device)
+{
+	int err;
+	struct snd_info_entry *entry;
+	char name[16];
+	struct snd_rawmidi *rmidi = device->device_data;
+
+	if (rmidi->device >= SNDRV_RAWMIDI_DEVICES)
+		return -ENOMEM;
+	err = 0;
+	mutex_lock(&register_mutex);
+	if (snd_rawmidi_search(rmidi->card, rmidi->device))
+		err = -EBUSY;
+	else
+		list_add_tail(&rmidi->list, &snd_rawmidi_devices);
+	mutex_unlock(&register_mutex);
+	if (err < 0)
+		return err;
+
+	err = snd_register_device(SNDRV_DEVICE_TYPE_RAWMIDI,
+				  rmidi->card, rmidi->device,
+				  &snd_rawmidi_f_ops, rmidi, rmidi->dev);
+	if (err < 0) {
+		rmidi_err(rmidi, "unable to register\n");
+		goto error;
+	}
+	if (rmidi->ops && rmidi->ops->dev_register) {
+		err = rmidi->ops->dev_register(rmidi);
+		if (err < 0)
+			goto error_unregister;
+	}
+#ifdef CONFIG_SND_OSSEMUL
+	rmidi->ossreg = 0;
+	if (!rawmidi_is_ump(rmidi) &&
+	    (int)rmidi->device == midi_map[rmidi->card->number]) {
+		if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI,
+					    rmidi->card, 0, &snd_rawmidi_f_ops,
+					    rmidi) < 0) {
+			rmidi_err(rmidi,
+				  "unable to register OSS rawmidi device %i:%i\n",
+				  rmidi->card->number, 0);
+		} else {
+			rmidi->ossreg++;
+#ifdef SNDRV_OSS_INFO_DEV_MIDI
+			snd_oss_info_register(SNDRV_OSS_INFO_DEV_MIDI, rmidi->card->number, rmidi->name);
+#endif
+		}
+	}
+	if (!rawmidi_is_ump(rmidi) &&
+	    (int)rmidi->device == amidi_map[rmidi->card->number]) {
+		if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI,
+					    rmidi->card, 1, &snd_rawmidi_f_ops,
+					    rmidi) < 0) {
+			rmidi_err(rmidi,
+				  "unable to register OSS rawmidi device %i:%i\n",
+				  rmidi->card->number, 1);
+		} else {
+			rmidi->ossreg++;
+		}
+	}
+#endif /* CONFIG_SND_OSSEMUL */
+	sprintf(name, "midi%d", rmidi->device);
+	entry = snd_info_create_card_entry(rmidi->card, name, rmidi->card->proc_root);
+	if (entry) {
+		entry->private_data = rmidi;
+		entry->c.text.read = snd_rawmidi_proc_info_read;
+		if (snd_info_register(entry) < 0) {
+			snd_info_free_entry(entry);
+			entry = NULL;
+		}
+	}
+	rmidi->proc_entry = entry;
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+	/* no own registration mechanism? */
+	if (!rmidi->ops || !rmidi->ops->dev_register) {
+		if (snd_seq_device_new(rmidi->card, rmidi->device, SNDRV_SEQ_DEV_ID_MIDISYNTH, 0, &rmidi->seq_dev) >= 0) {
+			rmidi->seq_dev->private_data = rmidi;
+			rmidi->seq_dev->private_free = snd_rawmidi_dev_seq_free;
+			sprintf(rmidi->seq_dev->name, "MIDI %d-%d", rmidi->card->number, rmidi->device);
+			snd_device_register(rmidi->card, rmidi->seq_dev);
+		}
+	}
+#endif
+	return 0;
+
+ error_unregister:
+	snd_unregister_device(rmidi->dev);
+ error:
+	mutex_lock(&register_mutex);
+	list_del(&rmidi->list);
+	mutex_unlock(&register_mutex);
+	return err;
+}
+
+static int snd_rawmidi_dev_disconnect(struct snd_device *device)
+{
+	struct snd_rawmidi *rmidi = device->device_data;
+	int dir;
+
+	mutex_lock(&register_mutex);
+	mutex_lock(&rmidi->open_mutex);
+	wake_up(&rmidi->open_wait);
+	list_del_init(&rmidi->list);
+	for (dir = 0; dir < 2; dir++) {
+		struct snd_rawmidi_substream *s;
+
+		list_for_each_entry(s, &rmidi->streams[dir].substreams, list) {
+			if (s->runtime)
+				wake_up(&s->runtime->sleep);
+		}
+	}
+
+#ifdef CONFIG_SND_OSSEMUL
+	if (rmidi->ossreg) {
+		if ((int)rmidi->device == midi_map[rmidi->card->number]) {
+			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI, rmidi->card, 0);
+#ifdef SNDRV_OSS_INFO_DEV_MIDI
+			snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIDI, rmidi->card->number);
+#endif
+		}
+		if ((int)rmidi->device == amidi_map[rmidi->card->number])
+			snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI, rmidi->card, 1);
+		rmidi->ossreg = 0;
+	}
+#endif /* CONFIG_SND_OSSEMUL */
+	snd_unregister_device(rmidi->dev);
+	mutex_unlock(&rmidi->open_mutex);
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+/**
+ * snd_rawmidi_set_ops - set the rawmidi operators
+ * @rmidi: the rawmidi instance
+ * @stream: the stream direction, SNDRV_RAWMIDI_STREAM_XXX
+ * @ops: the operator table
+ *
+ * Sets the rawmidi operators for the given stream direction.
+ */
+void snd_rawmidi_set_ops(struct snd_rawmidi *rmidi, int stream,
+			 const struct snd_rawmidi_ops *ops)
+{
+	struct snd_rawmidi_substream *substream;
+
+	list_for_each_entry(substream, &rmidi->streams[stream].substreams, list)
+		substream->ops = ops;
+}
+EXPORT_SYMBOL(snd_rawmidi_set_ops);
+
+/*
+ *  ENTRY functions
+ */
+
+static int __init alsa_rawmidi_init(void)
+{
+
+	snd_ctl_register_ioctl(snd_rawmidi_control_ioctl);
+	snd_ctl_register_ioctl_compat(snd_rawmidi_control_ioctl);
+#ifdef CONFIG_SND_OSSEMUL
+	{ int i;
+	/* check device map table */
+	for (i = 0; i < SNDRV_CARDS; i++) {
+		if (midi_map[i] < 0 || midi_map[i] >= SNDRV_RAWMIDI_DEVICES) {
+			pr_err("ALSA: rawmidi: invalid midi_map[%d] = %d\n",
+			       i, midi_map[i]);
+			midi_map[i] = 0;
+		}
+		if (amidi_map[i] < 0 || amidi_map[i] >= SNDRV_RAWMIDI_DEVICES) {
+			pr_err("ALSA: rawmidi: invalid amidi_map[%d] = %d\n",
+			       i, amidi_map[i]);
+			amidi_map[i] = 1;
+		}
+	}
+	}
+#endif /* CONFIG_SND_OSSEMUL */
+	return 0;
+}
+
+static void __exit alsa_rawmidi_exit(void)
+{
+	snd_ctl_unregister_ioctl(snd_rawmidi_control_ioctl);
+	snd_ctl_unregister_ioctl_compat(snd_rawmidi_control_ioctl);
+}
+
+module_init(alsa_rawmidi_init)
+module_exit(alsa_rawmidi_exit)
diff --git a/sound/core/rawmidi_compat.c b/sound/core/rawmidi_compat.c
new file mode 100644
index 0000000000..b81b30d82f
--- /dev/null
+++ b/sound/core/rawmidi_compat.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   32bit -> 64bit ioctl wrapper for raw MIDI API
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ */
+
+/* This file included from rawmidi.c */
+
+#include <linux/compat.h>
+
+struct snd_rawmidi_params32 {
+	s32 stream;
+	u32 buffer_size;
+	u32 avail_min;
+	unsigned int no_active_sensing; /* avoid bit-field */
+	unsigned int mode;
+	unsigned char reserved[12];
+} __attribute__((packed));
+
+static int snd_rawmidi_ioctl_params_compat(struct snd_rawmidi_file *rfile,
+					   struct snd_rawmidi_params32 __user *src)
+{
+	struct snd_rawmidi_params params;
+	unsigned int val;
+
+	if (get_user(params.stream, &src->stream) ||
+	    get_user(params.buffer_size, &src->buffer_size) ||
+	    get_user(params.avail_min, &src->avail_min) ||
+	    get_user(params.mode, &src->mode) ||
+	    get_user(val, &src->no_active_sensing))
+		return -EFAULT;
+	params.no_active_sensing = val;
+	switch (params.stream) {
+	case SNDRV_RAWMIDI_STREAM_OUTPUT:
+		if (!rfile->output)
+			return -EINVAL;
+		return snd_rawmidi_output_params(rfile->output, &params);
+	case SNDRV_RAWMIDI_STREAM_INPUT:
+		if (!rfile->input)
+			return -EINVAL;
+		return snd_rawmidi_input_params(rfile->input, &params);
+	}
+	return -EINVAL;
+}
+
+struct compat_snd_rawmidi_status64 {
+	s32 stream;
+	u8 rsvd[4]; /* alignment */
+	s64 tstamp_sec;
+	s64 tstamp_nsec;
+	u32 avail;
+	u32 xruns;
+	unsigned char reserved[16];
+} __attribute__((packed));
+
+static int snd_rawmidi_ioctl_status_compat64(struct snd_rawmidi_file *rfile,
+					     struct compat_snd_rawmidi_status64 __user *src)
+{
+	int err;
+	struct snd_rawmidi_status64 status;
+	struct compat_snd_rawmidi_status64 compat_status;
+
+	if (get_user(status.stream, &src->stream))
+		return -EFAULT;
+
+	switch (status.stream) {
+	case SNDRV_RAWMIDI_STREAM_OUTPUT:
+		if (!rfile->output)
+			return -EINVAL;
+		err = snd_rawmidi_output_status(rfile->output, &status);
+		break;
+	case SNDRV_RAWMIDI_STREAM_INPUT:
+		if (!rfile->input)
+			return -EINVAL;
+		err = snd_rawmidi_input_status(rfile->input, &status);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+
+	compat_status = (struct compat_snd_rawmidi_status64) {
+		.stream = status.stream,
+		.tstamp_sec = status.tstamp_sec,
+		.tstamp_nsec = status.tstamp_nsec,
+		.avail = status.avail,
+		.xruns = status.xruns,
+	};
+
+	if (copy_to_user(src, &compat_status, sizeof(*src)))
+		return -EFAULT;
+
+	return 0;
+}
+
+enum {
+	SNDRV_RAWMIDI_IOCTL_PARAMS32 = _IOWR('W', 0x10, struct snd_rawmidi_params32),
+	SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32 = _IOWR('W', 0x20, struct snd_rawmidi_status32),
+	SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64 = _IOWR('W', 0x20, struct compat_snd_rawmidi_status64),
+};
+
+static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_rawmidi_file *rfile;
+	void __user *argp = compat_ptr(arg);
+
+	rfile = file->private_data;
+	switch (cmd) {
+	case SNDRV_RAWMIDI_IOCTL_PVERSION:
+	case SNDRV_RAWMIDI_IOCTL_INFO:
+	case SNDRV_RAWMIDI_IOCTL_DROP:
+	case SNDRV_RAWMIDI_IOCTL_DRAIN:
+#if IS_ENABLED(CONFIG_SND_UMP)
+	case SNDRV_UMP_IOCTL_ENDPOINT_INFO:
+	case SNDRV_UMP_IOCTL_BLOCK_INFO:
+#endif
+		return snd_rawmidi_ioctl(file, cmd, (unsigned long)argp);
+	case SNDRV_RAWMIDI_IOCTL_PARAMS32:
+		return snd_rawmidi_ioctl_params_compat(rfile, argp);
+	case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32:
+		return snd_rawmidi_ioctl_status32(rfile, argp);
+	case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64:
+		return snd_rawmidi_ioctl_status_compat64(rfile, argp);
+	}
+	return -ENOIOCTLCMD;
+}
diff --git a/sound/core/seq/Kconfig b/sound/core/seq/Kconfig
new file mode 100644
index 0000000000..c14981daf9
--- /dev/null
+++ b/sound/core/seq/Kconfig
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SND_SEQUENCER
+	tristate "Sequencer support"
+	select SND_TIMER
+	select SND_SEQ_DEVICE
+	help
+	  Say Y or M to enable MIDI sequencer and router support.  This
+	  feature allows routing and enqueueing of MIDI events.  Events
+	  can be processed at a given time.
+
+	  Many programs require this feature, so you should enable it
+	  unless you know what you're doing.
+
+if SND_SEQUENCER
+
+config SND_SEQ_DUMMY
+	tristate "Sequencer dummy client"
+	help
+	  Say Y here to enable the dummy sequencer client.  This client
+	  is a simple MIDI-through client: all normal input events are
+	  redirected to the output port immediately.
+
+	  You don't need this unless you want to connect many MIDI
+	  devices or applications together.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-seq-dummy.
+
+config SND_SEQUENCER_OSS
+	tristate "OSS Sequencer API"
+	depends on SND_OSSEMUL
+	select SND_SEQ_MIDI_EVENT
+	help
+	  Say Y here to enable OSS sequencer emulation (both
+	  /dev/sequencer and /dev/music interfaces).
+
+	  Many programs still use the OSS API, so say Y.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-seq-oss.
+
+config SND_SEQ_HRTIMER_DEFAULT
+	bool "Use HR-timer as default sequencer timer"
+	depends on SND_HRTIMER
+	default y
+	help
+	  Say Y here to use the HR-timer backend as the default sequencer
+	  timer.
+
+config SND_SEQ_MIDI_EVENT
+	tristate
+
+config SND_SEQ_MIDI
+	def_tristate SND_RAWMIDI
+	select SND_SEQ_MIDI_EVENT
+
+config SND_SEQ_MIDI_EMUL
+	tristate
+
+config SND_SEQ_VIRMIDI
+	tristate
+
+config SND_SEQ_UMP
+	bool "Support for UMP events"
+	default y if SND_SEQ_UMP_CLIENT
+	help
+	  Say Y here to enable the support for handling UMP (Universal MIDI
+	  Packet) events via ALSA sequencer infrastructure, which is an
+	  essential feature for enabling MIDI 2.0 support.
+	  It includes the automatic conversion of ALSA sequencer events
+	  among legacy and UMP clients.
+
+config SND_SEQ_UMP_CLIENT
+	tristate
+	def_tristate SND_UMP
+
+endif # SND_SEQUENCER
diff --git a/sound/core/seq/Makefile b/sound/core/seq/Makefile
new file mode 100644
index 0000000000..990eec7c83
--- /dev/null
+++ b/sound/core/seq/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for ALSA
+# Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-seq-objs := seq.o seq_lock.o seq_clientmgr.o seq_memory.o seq_queue.o \
+                seq_fifo.o seq_prioq.o seq_timer.o \
+                seq_system.o seq_ports.o
+snd-seq-$(CONFIG_SND_PROC_FS) += seq_info.o
+snd-seq-$(CONFIG_SND_SEQ_UMP) += seq_ump_convert.o
+snd-seq-midi-objs := seq_midi.o
+snd-seq-midi-emul-objs := seq_midi_emul.o
+snd-seq-midi-event-objs := seq_midi_event.o
+snd-seq-dummy-objs := seq_dummy.o
+snd-seq-virmidi-objs := seq_virmidi.o
+snd-seq-ump-client-objs := seq_ump_client.o
+
+obj-$(CONFIG_SND_SEQUENCER) += snd-seq.o
+obj-$(CONFIG_SND_SEQUENCER_OSS) += oss/
+
+obj-$(CONFIG_SND_SEQ_DUMMY) += snd-seq-dummy.o
+obj-$(CONFIG_SND_SEQ_MIDI) += snd-seq-midi.o
+obj-$(CONFIG_SND_SEQ_UMP_CLIENT) += snd-seq-ump-client.o
+obj-$(CONFIG_SND_SEQ_MIDI_EMUL) += snd-seq-midi-emul.o
+obj-$(CONFIG_SND_SEQ_MIDI_EVENT) += snd-seq-midi-event.o
+obj-$(CONFIG_SND_SEQ_VIRMIDI) += snd-seq-virmidi.o
diff --git a/sound/core/seq/oss/Makefile b/sound/core/seq/oss/Makefile
new file mode 100644
index 0000000000..f1a6087854
--- /dev/null
+++ b/sound/core/seq/oss/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for ALSA
+# Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-seq-oss-objs  := seq_oss.o seq_oss_init.o seq_oss_timer.o seq_oss_ioctl.o \
+		     seq_oss_event.o seq_oss_rw.o seq_oss_synth.o \
+		     seq_oss_midi.o seq_oss_readq.o seq_oss_writeq.o
+
+obj-$(CONFIG_SND_SEQUENCER_OSS) += snd-seq-oss.o
diff --git a/sound/core/seq/oss/seq_oss.c b/sound/core/seq/oss/seq_oss.c
new file mode 100644
index 0000000000..77c1214acd
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * registration of device and proc
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/compat.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/initval.h>
+#include "seq_oss_device.h"
+#include "seq_oss_synth.h"
+
+/*
+ * module option
+ */
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("OSS-compatible sequencer module");
+MODULE_LICENSE("GPL");
+/* Takashi says this is really only for sound-service-0-, but this is OK. */
+MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_SEQUENCER);
+MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_MUSIC);
+
+
+/*
+ * prototypes
+ */
+static int register_device(void);
+static void unregister_device(void);
+#ifdef CONFIG_SND_PROC_FS
+static int register_proc(void);
+static void unregister_proc(void);
+#else
+static inline int register_proc(void) { return 0; }
+static inline void unregister_proc(void) {}
+#endif
+
+static int odev_open(struct inode *inode, struct file *file);
+static int odev_release(struct inode *inode, struct file *file);
+static ssize_t odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset);
+static ssize_t odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset);
+static long odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+static __poll_t odev_poll(struct file *file, poll_table * wait);
+
+
+/*
+ * module interface
+ */
+
+static struct snd_seq_driver seq_oss_synth_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.probe = snd_seq_oss_synth_probe,
+		.remove = snd_seq_oss_synth_remove,
+	},
+	.id = SNDRV_SEQ_DEV_ID_OSS,
+	.argsize = sizeof(struct snd_seq_oss_reg),
+};
+
+static int __init alsa_seq_oss_init(void)
+{
+	int rc;
+
+	rc = register_device();
+	if (rc < 0)
+		goto error;
+	rc = register_proc();
+	if (rc < 0) {
+		unregister_device();
+		goto error;
+	}
+	rc = snd_seq_oss_create_client();
+	if (rc < 0) {
+		unregister_proc();
+		unregister_device();
+		goto error;
+	}
+
+	rc = snd_seq_driver_register(&seq_oss_synth_driver);
+	if (rc < 0) {
+		snd_seq_oss_delete_client();
+		unregister_proc();
+		unregister_device();
+		goto error;
+	}
+
+	/* success */
+	snd_seq_oss_synth_init();
+
+ error:
+	return rc;
+}
+
+static void __exit alsa_seq_oss_exit(void)
+{
+	snd_seq_driver_unregister(&seq_oss_synth_driver);
+	snd_seq_oss_delete_client();
+	unregister_proc();
+	unregister_device();
+}
+
+module_init(alsa_seq_oss_init)
+module_exit(alsa_seq_oss_exit)
+
+/*
+ * ALSA minor device interface
+ */
+
+static DEFINE_MUTEX(register_mutex);
+
+static int
+odev_open(struct inode *inode, struct file *file)
+{
+	int level, rc;
+
+	if (iminor(inode) == SNDRV_MINOR_OSS_MUSIC)
+		level = SNDRV_SEQ_OSS_MODE_MUSIC;
+	else
+		level = SNDRV_SEQ_OSS_MODE_SYNTH;
+
+	mutex_lock(&register_mutex);
+	rc = snd_seq_oss_open(file, level);
+	mutex_unlock(&register_mutex);
+
+	return rc;
+}
+
+static int
+odev_release(struct inode *inode, struct file *file)
+{
+	struct seq_oss_devinfo *dp;
+
+	dp = file->private_data;
+	if (!dp)
+		return 0;
+
+	mutex_lock(&register_mutex);
+	snd_seq_oss_release(dp);
+	mutex_unlock(&register_mutex);
+
+	return 0;
+}
+
+static ssize_t
+odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
+{
+	struct seq_oss_devinfo *dp;
+	dp = file->private_data;
+	if (snd_BUG_ON(!dp))
+		return -ENXIO;
+	return snd_seq_oss_read(dp, buf, count);
+}
+
+
+static ssize_t
+odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
+{
+	struct seq_oss_devinfo *dp;
+	dp = file->private_data;
+	if (snd_BUG_ON(!dp))
+		return -ENXIO;
+	return snd_seq_oss_write(dp, buf, count, file);
+}
+
+static long
+odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct seq_oss_devinfo *dp;
+	long rc;
+
+	dp = file->private_data;
+	if (snd_BUG_ON(!dp))
+		return -ENXIO;
+
+	if (cmd != SNDCTL_SEQ_SYNC &&
+	    mutex_lock_interruptible(&register_mutex))
+		return -ERESTARTSYS;
+	rc = snd_seq_oss_ioctl(dp, cmd, arg);
+	if (cmd != SNDCTL_SEQ_SYNC)
+		mutex_unlock(&register_mutex);
+	return rc;
+}
+
+#ifdef CONFIG_COMPAT
+static long odev_ioctl_compat(struct file *file, unsigned int cmd,
+			      unsigned long arg)
+{
+	return odev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#else
+#define odev_ioctl_compat	NULL
+#endif
+
+static __poll_t
+odev_poll(struct file *file, poll_table * wait)
+{
+	struct seq_oss_devinfo *dp;
+	dp = file->private_data;
+	if (snd_BUG_ON(!dp))
+		return EPOLLERR;
+	return snd_seq_oss_poll(dp, file, wait);
+}
+
+/*
+ * registration of sequencer minor device
+ */
+
+static const struct file_operations seq_oss_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.read =		odev_read,
+	.write =	odev_write,
+	.open =		odev_open,
+	.release =	odev_release,
+	.poll =		odev_poll,
+	.unlocked_ioctl =	odev_ioctl,
+	.compat_ioctl =	odev_ioctl_compat,
+	.llseek =	noop_llseek,
+};
+
+static int __init
+register_device(void)
+{
+	int rc;
+
+	mutex_lock(&register_mutex);
+	rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER,
+				     NULL, 0,
+				     &seq_oss_f_ops, NULL);
+	if (rc < 0) {
+		pr_err("ALSA: seq_oss: can't register device seq\n");
+		mutex_unlock(&register_mutex);
+		return rc;
+	}
+	rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC,
+				     NULL, 0,
+				     &seq_oss_f_ops, NULL);
+	if (rc < 0) {
+		pr_err("ALSA: seq_oss: can't register device music\n");
+		snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0);
+		mutex_unlock(&register_mutex);
+		return rc;
+	}
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+static void
+unregister_device(void)
+{
+	mutex_lock(&register_mutex);
+	if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC, NULL, 0) < 0)		
+		pr_err("ALSA: seq_oss: error unregister device music\n");
+	if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0) < 0)
+		pr_err("ALSA: seq_oss: error unregister device seq\n");
+	mutex_unlock(&register_mutex);
+}
+
+/*
+ * /proc interface
+ */
+
+#ifdef CONFIG_SND_PROC_FS
+
+static struct snd_info_entry *info_entry;
+
+static void
+info_read(struct snd_info_entry *entry, struct snd_info_buffer *buf)
+{
+	mutex_lock(&register_mutex);
+	snd_iprintf(buf, "OSS sequencer emulation version %s\n", SNDRV_SEQ_OSS_VERSION_STR);
+	snd_seq_oss_system_info_read(buf);
+	snd_seq_oss_synth_info_read(buf);
+	snd_seq_oss_midi_info_read(buf);
+	mutex_unlock(&register_mutex);
+}
+
+
+static int __init
+register_proc(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, SNDRV_SEQ_OSS_PROCNAME, snd_seq_root);
+	if (entry == NULL)
+		return -ENOMEM;
+
+	entry->content = SNDRV_INFO_CONTENT_TEXT;
+	entry->private_data = NULL;
+	entry->c.text.read = info_read;
+	if (snd_info_register(entry) < 0) {
+		snd_info_free_entry(entry);
+		return -ENOMEM;
+	}
+	info_entry = entry;
+	return 0;
+}
+
+static void
+unregister_proc(void)
+{
+	snd_info_free_entry(info_entry);
+	info_entry = NULL;
+}
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/seq/oss/seq_oss_device.h b/sound/core/seq/oss/seq_oss_device.h
new file mode 100644
index 0000000000..6c2c4fb9b7
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_device.h
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_DEVICE_H
+#define __SEQ_OSS_DEVICE_H
+
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <sound/core.h>
+#include <sound/seq_oss.h>
+#include <sound/rawmidi.h>
+#include <sound/seq_kernel.h>
+#include <sound/info.h>
+#include "../seq_clientmgr.h"
+
+/* max. applications */
+#define SNDRV_SEQ_OSS_MAX_CLIENTS	16
+#define SNDRV_SEQ_OSS_MAX_SYNTH_DEVS	16
+#define SNDRV_SEQ_OSS_MAX_MIDI_DEVS	32
+
+/* version */
+#define SNDRV_SEQ_OSS_MAJOR_VERSION	0
+#define SNDRV_SEQ_OSS_MINOR_VERSION	1
+#define SNDRV_SEQ_OSS_TINY_VERSION	8
+#define SNDRV_SEQ_OSS_VERSION_STR	"0.1.8"
+
+/* device and proc interface name */
+#define SNDRV_SEQ_OSS_PROCNAME		"oss"
+
+
+/*
+ * type definitions
+ */
+
+typedef unsigned int reltime_t;
+typedef unsigned int abstime_t;
+
+
+/*
+ * synthesizer channel information
+ */
+struct seq_oss_chinfo {
+	int note, vel;
+};
+
+/*
+ * synthesizer information
+ */
+struct seq_oss_synthinfo {
+	struct snd_seq_oss_arg arg;
+	struct seq_oss_chinfo *ch;
+	struct seq_oss_synth_sysex *sysex;
+	int nr_voices;
+	int opened;
+	int is_midi;
+	int midi_mapped;
+};
+
+
+/*
+ * sequencer client information
+ */
+
+struct seq_oss_devinfo {
+
+	int index;	/* application index */
+	int cseq;	/* sequencer client number */
+	int port;	/* sequencer port number */
+	int queue;	/* sequencer queue number */
+
+	struct snd_seq_addr addr;	/* address of this device */
+
+	int seq_mode;	/* sequencer mode */
+	int file_mode;	/* file access */
+
+	/* midi device table */
+	int max_mididev;
+
+	/* synth device table */
+	int max_synthdev;
+	struct seq_oss_synthinfo synths[SNDRV_SEQ_OSS_MAX_SYNTH_DEVS];
+	int synth_opened;
+
+	/* output queue */
+	struct seq_oss_writeq *writeq;
+
+	/* midi input queue */
+	struct seq_oss_readq *readq;
+
+	/* timer */
+	struct seq_oss_timer *timer;
+};
+
+
+/*
+ * function prototypes
+ */
+
+/* create/delete OSS sequencer client */
+int snd_seq_oss_create_client(void);
+int snd_seq_oss_delete_client(void);
+
+/* device file interface */
+int snd_seq_oss_open(struct file *file, int level);
+void snd_seq_oss_release(struct seq_oss_devinfo *dp);
+int snd_seq_oss_ioctl(struct seq_oss_devinfo *dp, unsigned int cmd, unsigned long arg);
+int snd_seq_oss_read(struct seq_oss_devinfo *dev, char __user *buf, int count);
+int snd_seq_oss_write(struct seq_oss_devinfo *dp, const char __user *buf, int count, struct file *opt);
+__poll_t snd_seq_oss_poll(struct seq_oss_devinfo *dp, struct file *file, poll_table * wait);
+
+void snd_seq_oss_reset(struct seq_oss_devinfo *dp);
+
+/* */
+void snd_seq_oss_process_queue(struct seq_oss_devinfo *dp, abstime_t time);
+
+
+/* proc interface */
+void snd_seq_oss_system_info_read(struct snd_info_buffer *buf);
+void snd_seq_oss_midi_info_read(struct snd_info_buffer *buf);
+void snd_seq_oss_synth_info_read(struct snd_info_buffer *buf);
+void snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf);
+
+/* file mode macros */
+#define is_read_mode(mode)	((mode) & SNDRV_SEQ_OSS_FILE_READ)
+#define is_write_mode(mode)	((mode) & SNDRV_SEQ_OSS_FILE_WRITE)
+#define is_nonblock_mode(mode)	((mode) & SNDRV_SEQ_OSS_FILE_NONBLOCK)
+
+/* dispatch event */
+static inline int
+snd_seq_oss_dispatch(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, int atomic, int hop)
+{
+	return snd_seq_kernel_client_dispatch(dp->cseq, ev, atomic, hop);
+}
+
+/* ioctl for writeq */
+static inline int
+snd_seq_oss_control(struct seq_oss_devinfo *dp, unsigned int type, void *arg)
+{
+	int err;
+
+	snd_seq_client_ioctl_lock(dp->cseq);
+	err = snd_seq_kernel_client_ctl(dp->cseq, type, arg);
+	snd_seq_client_ioctl_unlock(dp->cseq);
+	return err;
+}
+
+/* fill the addresses in header */
+static inline void
+snd_seq_oss_fill_addr(struct seq_oss_devinfo *dp, struct snd_seq_event *ev,
+		     int dest_client, int dest_port)
+{
+	ev->queue = dp->queue;
+	ev->source = dp->addr;
+	ev->dest.client = dest_client;
+	ev->dest.port = dest_port;
+}
+
+
+/* misc. functions for proc interface */
+char *enabled_str(int bool);
+
+#endif /* __SEQ_OSS_DEVICE_H */
diff --git a/sound/core/seq/oss/seq_oss_event.c b/sound/core/seq/oss/seq_oss_event.c
new file mode 100644
index 0000000000..7b7c925dd3
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_event.c
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_device.h"
+#include "seq_oss_synth.h"
+#include "seq_oss_midi.h"
+#include "seq_oss_event.h"
+#include "seq_oss_timer.h"
+#include <sound/seq_oss_legacy.h>
+#include "seq_oss_readq.h"
+#include "seq_oss_writeq.h"
+#include <linux/nospec.h>
+
+
+/*
+ * prototypes
+ */
+static int extended_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev);
+static int chn_voice_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
+static int chn_common_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
+static int timing_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
+static int local_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
+static int old_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev);
+static int note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev);
+static int note_off_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev);
+static int set_note_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int note, int vel, struct snd_seq_event *ev);
+static int set_control_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int param, int val, struct snd_seq_event *ev);
+static int set_echo_event(struct seq_oss_devinfo *dp, union evrec *rec, struct snd_seq_event *ev);
+
+
+/*
+ * convert an OSS event to ALSA event
+ * return 0 : enqueued
+ *        non-zero : invalid - ignored
+ */
+
+int
+snd_seq_oss_process_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	switch (q->s.code) {
+	case SEQ_EXTENDED:
+		return extended_event(dp, q, ev);
+
+	case EV_CHN_VOICE:
+		return chn_voice_event(dp, q, ev);
+
+	case EV_CHN_COMMON:
+		return chn_common_event(dp, q, ev);
+
+	case EV_TIMING:
+		return timing_event(dp, q, ev);
+
+	case EV_SEQ_LOCAL:
+		return local_event(dp, q, ev);
+
+	case EV_SYSEX:
+		return snd_seq_oss_synth_sysex(dp, q->x.dev, q->x.buf, ev);
+
+	case SEQ_MIDIPUTC:
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
+			return -EINVAL;
+		/* put a midi byte */
+		if (! is_write_mode(dp->file_mode))
+			break;
+		if (snd_seq_oss_midi_open(dp, q->s.dev, SNDRV_SEQ_OSS_FILE_WRITE))
+			break;
+		if (snd_seq_oss_midi_filemode(dp, q->s.dev) & SNDRV_SEQ_OSS_FILE_WRITE)
+			return snd_seq_oss_midi_putc(dp, q->s.dev, q->s.parm1, ev);
+		break;
+
+	case SEQ_ECHO:
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
+			return -EINVAL;
+		return set_echo_event(dp, q, ev);
+
+	case SEQ_PRIVATE:
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
+			return -EINVAL;
+		return snd_seq_oss_synth_raw_event(dp, q->c[1], q->c, ev);
+
+	default:
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
+			return -EINVAL;
+		return old_event(dp, q, ev);
+	}
+	return -EINVAL;
+}
+
+/* old type events: mode1 only */
+static int
+old_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	switch (q->s.code) {
+	case SEQ_NOTEOFF:
+		return note_off_event(dp, 0, q->n.chn, q->n.note, q->n.vel, ev);
+
+	case SEQ_NOTEON:
+		return note_on_event(dp, 0, q->n.chn, q->n.note, q->n.vel, ev);
+
+	case SEQ_WAIT:
+		/* skip */
+		break;
+
+	case SEQ_PGMCHANGE:
+		return set_control_event(dp, 0, SNDRV_SEQ_EVENT_PGMCHANGE,
+					 q->n.chn, 0, q->n.note, ev);
+
+	case SEQ_SYNCTIMER:
+		return snd_seq_oss_timer_reset(dp->timer);
+	}
+
+	return -EINVAL;
+}
+
+/* 8bytes extended event: mode1 only */
+static int
+extended_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	int val;
+
+	switch (q->e.cmd) {
+	case SEQ_NOTEOFF:
+		return note_off_event(dp, q->e.dev, q->e.chn, q->e.p1, q->e.p2, ev);
+
+	case SEQ_NOTEON:
+		return note_on_event(dp, q->e.dev, q->e.chn, q->e.p1, q->e.p2, ev);
+
+	case SEQ_PGMCHANGE:
+		return set_control_event(dp, q->e.dev, SNDRV_SEQ_EVENT_PGMCHANGE,
+					 q->e.chn, 0, q->e.p1, ev);
+
+	case SEQ_AFTERTOUCH:
+		return set_control_event(dp, q->e.dev, SNDRV_SEQ_EVENT_CHANPRESS,
+					 q->e.chn, 0, q->e.p1, ev);
+
+	case SEQ_BALANCE:
+		/* convert -128:127 to 0:127 */
+		val = (char)q->e.p1;
+		val = (val + 128) / 2;
+		return set_control_event(dp, q->e.dev, SNDRV_SEQ_EVENT_CONTROLLER,
+					 q->e.chn, CTL_PAN, val, ev);
+
+	case SEQ_CONTROLLER:
+		val = ((short)q->e.p3 << 8) | (short)q->e.p2;
+		switch (q->e.p1) {
+		case CTRL_PITCH_BENDER: /* SEQ1 V2 control */
+			/* -0x2000:0x1fff */
+			return set_control_event(dp, q->e.dev,
+						 SNDRV_SEQ_EVENT_PITCHBEND,
+						 q->e.chn, 0, val, ev);
+		case CTRL_PITCH_BENDER_RANGE:
+			/* conversion: 100/semitone -> 128/semitone */
+			return set_control_event(dp, q->e.dev,
+						 SNDRV_SEQ_EVENT_REGPARAM,
+						 q->e.chn, 0, val*128/100, ev);
+		default:
+			return set_control_event(dp, q->e.dev,
+						  SNDRV_SEQ_EVENT_CONTROL14,
+						  q->e.chn, q->e.p1, val, ev);
+		}
+
+	case SEQ_VOLMODE:
+		return snd_seq_oss_synth_raw_event(dp, q->e.dev, q->c, ev);
+
+	}
+	return -EINVAL;
+}
+
+/* channel voice events: mode1 and 2 */
+static int
+chn_voice_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	if (q->v.chn >= 32)
+		return -EINVAL;
+	switch (q->v.cmd) {
+	case MIDI_NOTEON:
+		return note_on_event(dp, q->v.dev, q->v.chn, q->v.note, q->v.parm, ev);
+
+	case MIDI_NOTEOFF:
+		return note_off_event(dp, q->v.dev, q->v.chn, q->v.note, q->v.parm, ev);
+
+	case MIDI_KEY_PRESSURE:
+		return set_note_event(dp, q->v.dev, SNDRV_SEQ_EVENT_KEYPRESS,
+				       q->v.chn, q->v.note, q->v.parm, ev);
+
+	}
+	return -EINVAL;
+}
+
+/* channel common events: mode1 and 2 */
+static int
+chn_common_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	if (q->l.chn >= 32)
+		return -EINVAL;
+	switch (q->l.cmd) {
+	case MIDI_PGM_CHANGE:
+		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_PGMCHANGE,
+					  q->l.chn, 0, q->l.p1, ev);
+
+	case MIDI_CTL_CHANGE:
+		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_CONTROLLER,
+					  q->l.chn, q->l.p1, q->l.val, ev);
+
+	case MIDI_PITCH_BEND:
+		/* conversion: 0:0x3fff -> -0x2000:0x1fff */
+		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_PITCHBEND,
+					  q->l.chn, 0, q->l.val - 8192, ev);
+		
+	case MIDI_CHN_PRESSURE:
+		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_CHANPRESS,
+					  q->l.chn, 0, q->l.val, ev);
+	}
+	return -EINVAL;
+}
+
+/* timer events: mode1 and mode2 */
+static int
+timing_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	switch (q->t.cmd) {
+	case TMR_ECHO:
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
+			return set_echo_event(dp, q, ev);
+		else {
+			union evrec tmp;
+			memset(&tmp, 0, sizeof(tmp));
+			/* XXX: only for little-endian! */
+			tmp.echo = (q->t.time << 8) | SEQ_ECHO;
+			return set_echo_event(dp, &tmp, ev);
+		} 
+
+	case TMR_STOP:
+		if (dp->seq_mode)
+			return snd_seq_oss_timer_stop(dp->timer);
+		return 0;
+
+	case TMR_CONTINUE:
+		if (dp->seq_mode)
+			return snd_seq_oss_timer_continue(dp->timer);
+		return 0;
+
+	case TMR_TEMPO:
+		if (dp->seq_mode)
+			return snd_seq_oss_timer_tempo(dp->timer, q->t.time);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/* local events: mode1 and 2 */
+static int
+local_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
+{
+	return -EINVAL;
+}
+
+/*
+ * process note-on event for OSS synth
+ * three different modes are available:
+ * - SNDRV_SEQ_OSS_PROCESS_EVENTS  (for one-voice per channel mode)
+ *	Accept note 255 as volume change.
+ * - SNDRV_SEQ_OSS_PASS_EVENTS
+ *	Pass all events to lowlevel driver anyway
+ * - SNDRV_SEQ_OSS_PROCESS_KEYPRESS  (mostly for Emu8000)
+ *	Use key-pressure if note >= 128
+ */
+static int
+note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev)
+{
+	struct seq_oss_synthinfo *info;
+
+	info = snd_seq_oss_synth_info(dp, dev);
+	if (!info)
+		return -ENXIO;
+
+	switch (info->arg.event_passing) {
+	case SNDRV_SEQ_OSS_PROCESS_EVENTS:
+		if (! info->ch || ch < 0 || ch >= info->nr_voices) {
+			/* pass directly */
+			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
+		}
+
+		ch = array_index_nospec(ch, info->nr_voices);
+		if (note == 255 && info->ch[ch].note >= 0) {
+			/* volume control */
+			int type;
+			//if (! vel)
+				/* set volume to zero -- note off */
+			//	type = SNDRV_SEQ_EVENT_NOTEOFF;
+			//else
+				if (info->ch[ch].vel)
+				/* sample already started -- volume change */
+				type = SNDRV_SEQ_EVENT_KEYPRESS;
+			else
+				/* sample not started -- start now */
+				type = SNDRV_SEQ_EVENT_NOTEON;
+			info->ch[ch].vel = vel;
+			return set_note_event(dp, dev, type, ch, info->ch[ch].note, vel, ev);
+		} else if (note >= 128)
+			return -EINVAL; /* invalid */
+
+		if (note != info->ch[ch].note && info->ch[ch].note >= 0)
+			/* note changed - note off at beginning */
+			set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEOFF, ch, info->ch[ch].note, 0, ev);
+		/* set current status */
+		info->ch[ch].note = note;
+		info->ch[ch].vel = vel;
+		if (vel) /* non-zero velocity - start the note now */
+			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
+		return -EINVAL;
+		
+	case SNDRV_SEQ_OSS_PASS_EVENTS:
+		/* pass the event anyway */
+		return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
+
+	case SNDRV_SEQ_OSS_PROCESS_KEYPRESS:
+		if (note >= 128) /* key pressure: shifted by 128 */
+			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_KEYPRESS, ch, note - 128, vel, ev);
+		else /* normal note-on event */
+			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
+	}
+	return -EINVAL;
+}
+
+/*
+ * process note-off event for OSS synth
+ */
+static int
+note_off_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev)
+{
+	struct seq_oss_synthinfo *info;
+
+	info = snd_seq_oss_synth_info(dp, dev);
+	if (!info)
+		return -ENXIO;
+
+	switch (info->arg.event_passing) {
+	case SNDRV_SEQ_OSS_PROCESS_EVENTS:
+		if (! info->ch || ch < 0 || ch >= info->nr_voices) {
+			/* pass directly */
+			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
+		}
+
+		ch = array_index_nospec(ch, info->nr_voices);
+		if (info->ch[ch].note >= 0) {
+			note = info->ch[ch].note;
+			info->ch[ch].vel = 0;
+			info->ch[ch].note = -1;
+			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEOFF, ch, note, vel, ev);
+		}
+		return -EINVAL; /* invalid */
+
+	case SNDRV_SEQ_OSS_PASS_EVENTS:
+	case SNDRV_SEQ_OSS_PROCESS_KEYPRESS:
+		/* pass the event anyway */
+		return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEOFF, ch, note, vel, ev);
+
+	}
+	return -EINVAL;
+}
+
+/*
+ * create a note event
+ */
+static int
+set_note_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int note, int vel, struct snd_seq_event *ev)
+{
+	if (!snd_seq_oss_synth_info(dp, dev))
+		return -ENXIO;
+	
+	ev->type = type;
+	snd_seq_oss_synth_addr(dp, dev, ev);
+	ev->data.note.channel = ch;
+	ev->data.note.note = note;
+	ev->data.note.velocity = vel;
+
+	return 0;
+}
+
+/*
+ * create a control event
+ */
+static int
+set_control_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int param, int val, struct snd_seq_event *ev)
+{
+	if (!snd_seq_oss_synth_info(dp, dev))
+		return -ENXIO;
+	
+	ev->type = type;
+	snd_seq_oss_synth_addr(dp, dev, ev);
+	ev->data.control.channel = ch;
+	ev->data.control.param = param;
+	ev->data.control.value = val;
+
+	return 0;
+}
+
+/*
+ * create an echo event
+ */
+static int
+set_echo_event(struct seq_oss_devinfo *dp, union evrec *rec, struct snd_seq_event *ev)
+{
+	ev->type = SNDRV_SEQ_EVENT_ECHO;
+	/* echo back to itself */
+	snd_seq_oss_fill_addr(dp, ev, dp->addr.client, dp->addr.port);
+	memcpy(&ev->data, rec, LONG_EVENT_SIZE);
+	return 0;
+}
+
+/*
+ * event input callback from ALSA sequencer:
+ * the echo event is processed here.
+ */
+int
+snd_seq_oss_event_input(struct snd_seq_event *ev, int direct, void *private_data,
+			int atomic, int hop)
+{
+	struct seq_oss_devinfo *dp = (struct seq_oss_devinfo *)private_data;
+	union evrec *rec;
+
+	if (ev->type != SNDRV_SEQ_EVENT_ECHO)
+		return snd_seq_oss_midi_input(ev, direct, private_data);
+
+	if (ev->source.client != dp->cseq)
+		return 0; /* ignored */
+
+	rec = (union evrec*)&ev->data;
+	if (rec->s.code == SEQ_SYNCTIMER) {
+		/* sync echo back */
+		snd_seq_oss_writeq_wakeup(dp->writeq, rec->t.time);
+		
+	} else {
+		/* echo back event */
+		if (dp->readq == NULL)
+			return 0;
+		snd_seq_oss_readq_put_event(dp->readq, rec);
+	}
+	return 0;
+}
+
diff --git a/sound/core/seq/oss/seq_oss_event.h b/sound/core/seq/oss/seq_oss_event.h
new file mode 100644
index 0000000000..b4f723949a
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_event.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ *
+ * seq_oss_event.h - OSS event queue record
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_EVENT_H
+#define __SEQ_OSS_EVENT_H
+
+#include "seq_oss_device.h"
+
+#define SHORT_EVENT_SIZE	4
+#define LONG_EVENT_SIZE		8
+
+/* short event (4bytes) */
+struct evrec_short {
+	unsigned char code;
+	unsigned char parm1;
+	unsigned char dev;
+	unsigned char parm2;
+};
+	
+/* short note events (4bytes) */
+struct evrec_note {
+	unsigned char code;
+	unsigned char chn;
+	unsigned char note;
+	unsigned char vel;
+};
+	
+/* long timer events (8bytes) */
+struct evrec_timer {
+	unsigned char code;
+	unsigned char cmd;
+	unsigned char dummy1, dummy2;
+	unsigned int time;
+};
+
+/* long extended events (8bytes) */
+struct evrec_extended {
+	unsigned char code;
+	unsigned char cmd;
+	unsigned char dev;
+	unsigned char chn;
+	unsigned char p1, p2, p3, p4;
+};
+
+/* long channel events (8bytes) */
+struct evrec_long {
+	unsigned char code;
+	unsigned char dev;
+	unsigned char cmd;
+	unsigned char chn;
+	unsigned char p1, p2;
+	unsigned short val;
+};
+	
+/* channel voice events (8bytes) */
+struct evrec_voice {
+	unsigned char code;
+	unsigned char dev;
+	unsigned char cmd;
+	unsigned char chn;
+	unsigned char note, parm;
+	unsigned short dummy;
+};
+
+/* sysex events (8bytes) */
+struct evrec_sysex {
+	unsigned char code;
+	unsigned char dev;
+	unsigned char buf[6];
+};
+
+/* event record */
+union evrec {
+	struct evrec_short s;
+	struct evrec_note n;
+	struct evrec_long l;
+	struct evrec_voice v;
+	struct evrec_timer t;
+	struct evrec_extended e;
+	struct evrec_sysex x;
+	unsigned int echo;
+	unsigned char c[LONG_EVENT_SIZE];
+};
+
+#define ev_is_long(ev) ((ev)->s.code >= 128)
+#define ev_length(ev) ((ev)->s.code >= 128 ? LONG_EVENT_SIZE : SHORT_EVENT_SIZE)
+
+int snd_seq_oss_process_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev);
+int snd_seq_oss_process_timer_event(struct seq_oss_timer *rec, union evrec *q);
+int snd_seq_oss_event_input(struct snd_seq_event *ev, int direct, void *private_data, int atomic, int hop);
+
+
+#endif /* __SEQ_OSS_EVENT_H */
diff --git a/sound/core/seq/oss/seq_oss_init.c b/sound/core/seq/oss/seq_oss_init.c
new file mode 100644
index 0000000000..42d4e7535a
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_init.c
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * open/close and reset interface
+ *
+ * Copyright (C) 1998-1999 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_device.h"
+#include "seq_oss_synth.h"
+#include "seq_oss_midi.h"
+#include "seq_oss_writeq.h"
+#include "seq_oss_readq.h"
+#include "seq_oss_timer.h"
+#include "seq_oss_event.h"
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+/*
+ * common variables
+ */
+static int maxqlen = SNDRV_SEQ_OSS_MAX_QLEN;
+module_param(maxqlen, int, 0444);
+MODULE_PARM_DESC(maxqlen, "maximum queue length");
+
+static int system_client = -1; /* ALSA sequencer client number */
+static int system_port = -1;
+
+static int num_clients;
+static struct seq_oss_devinfo *client_table[SNDRV_SEQ_OSS_MAX_CLIENTS];
+
+
+/*
+ * prototypes
+ */
+static int receive_announce(struct snd_seq_event *ev, int direct, void *private, int atomic, int hop);
+static int translate_mode(struct file *file);
+static int create_port(struct seq_oss_devinfo *dp);
+static int delete_port(struct seq_oss_devinfo *dp);
+static int alloc_seq_queue(struct seq_oss_devinfo *dp);
+static int delete_seq_queue(int queue);
+static void free_devinfo(void *private);
+
+#define call_ctl(type,rec) snd_seq_kernel_client_ctl(system_client, type, rec)
+
+
+/* call snd_seq_oss_midi_lookup_ports() asynchronously */
+static void async_call_lookup_ports(struct work_struct *work)
+{
+	snd_seq_oss_midi_lookup_ports(system_client);
+}
+
+static DECLARE_WORK(async_lookup_work, async_call_lookup_ports);
+
+/*
+ * create sequencer client for OSS sequencer
+ */
+int __init
+snd_seq_oss_create_client(void)
+{
+	int rc;
+	struct snd_seq_port_info *port;
+	struct snd_seq_port_callback port_callback;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port) {
+		rc = -ENOMEM;
+		goto __error;
+	}
+
+	/* create ALSA client */
+	rc = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_OSS,
+					  "OSS sequencer");
+	if (rc < 0)
+		goto __error;
+
+	system_client = rc;
+
+	/* create announcement receiver port */
+	strcpy(port->name, "Receiver");
+	port->addr.client = system_client;
+	port->capability = SNDRV_SEQ_PORT_CAP_WRITE; /* receive only */
+	port->type = 0;
+
+	memset(&port_callback, 0, sizeof(port_callback));
+	/* don't set port_callback.owner here. otherwise the module counter
+	 * is incremented and we can no longer release the module..
+	 */
+	port_callback.event_input = receive_announce;
+	port->kernel = &port_callback;
+	
+	if (call_ctl(SNDRV_SEQ_IOCTL_CREATE_PORT, port) >= 0) {
+		struct snd_seq_port_subscribe subs;
+
+		system_port = port->addr.port;
+		memset(&subs, 0, sizeof(subs));
+		subs.sender.client = SNDRV_SEQ_CLIENT_SYSTEM;
+		subs.sender.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
+		subs.dest.client = system_client;
+		subs.dest.port = system_port;
+		call_ctl(SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, &subs);
+	}
+	rc = 0;
+
+	/* look up midi devices */
+	schedule_work(&async_lookup_work);
+
+ __error:
+	kfree(port);
+	return rc;
+}
+
+
+/*
+ * receive annoucement from system port, and check the midi device
+ */
+static int
+receive_announce(struct snd_seq_event *ev, int direct, void *private, int atomic, int hop)
+{
+	struct snd_seq_port_info pinfo;
+
+	if (atomic)
+		return 0; /* it must not happen */
+
+	switch (ev->type) {
+	case SNDRV_SEQ_EVENT_PORT_START:
+	case SNDRV_SEQ_EVENT_PORT_CHANGE:
+		if (ev->data.addr.client == system_client)
+			break; /* ignore myself */
+		memset(&pinfo, 0, sizeof(pinfo));
+		pinfo.addr = ev->data.addr;
+		if (call_ctl(SNDRV_SEQ_IOCTL_GET_PORT_INFO, &pinfo) >= 0)
+			snd_seq_oss_midi_check_new_port(&pinfo);
+		break;
+
+	case SNDRV_SEQ_EVENT_PORT_EXIT:
+		if (ev->data.addr.client == system_client)
+			break; /* ignore myself */
+		snd_seq_oss_midi_check_exit_port(ev->data.addr.client,
+						ev->data.addr.port);
+		break;
+	}
+	return 0;
+}
+
+
+/*
+ * delete OSS sequencer client
+ */
+int
+snd_seq_oss_delete_client(void)
+{
+	cancel_work_sync(&async_lookup_work);
+	if (system_client >= 0)
+		snd_seq_delete_kernel_client(system_client);
+
+	snd_seq_oss_midi_clear_all();
+
+	return 0;
+}
+
+
+/*
+ * open sequencer device
+ */
+int
+snd_seq_oss_open(struct file *file, int level)
+{
+	int i, rc;
+	struct seq_oss_devinfo *dp;
+
+	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
+	if (!dp)
+		return -ENOMEM;
+
+	dp->cseq = system_client;
+	dp->port = -1;
+	dp->queue = -1;
+
+	for (i = 0; i < SNDRV_SEQ_OSS_MAX_CLIENTS; i++) {
+		if (client_table[i] == NULL)
+			break;
+	}
+
+	dp->index = i;
+	if (i >= SNDRV_SEQ_OSS_MAX_CLIENTS) {
+		pr_debug("ALSA: seq_oss: too many applications\n");
+		rc = -ENOMEM;
+		goto _error;
+	}
+
+	/* look up synth and midi devices */
+	snd_seq_oss_synth_setup(dp);
+	snd_seq_oss_midi_setup(dp);
+
+	if (dp->synth_opened == 0 && dp->max_mididev == 0) {
+		/* pr_err("ALSA: seq_oss: no device found\n"); */
+		rc = -ENODEV;
+		goto _error;
+	}
+
+	/* create port */
+	rc = create_port(dp);
+	if (rc < 0) {
+		pr_err("ALSA: seq_oss: can't create port\n");
+		goto _error;
+	}
+
+	/* allocate queue */
+	rc = alloc_seq_queue(dp);
+	if (rc < 0)
+		goto _error;
+
+	/* set address */
+	dp->addr.client = dp->cseq;
+	dp->addr.port = dp->port;
+	/*dp->addr.queue = dp->queue;*/
+	/*dp->addr.channel = 0;*/
+
+	dp->seq_mode = level;
+
+	/* set up file mode */
+	dp->file_mode = translate_mode(file);
+
+	/* initialize read queue */
+	if (is_read_mode(dp->file_mode)) {
+		dp->readq = snd_seq_oss_readq_new(dp, maxqlen);
+		if (!dp->readq) {
+			rc = -ENOMEM;
+			goto _error;
+		}
+	}
+
+	/* initialize write queue */
+	if (is_write_mode(dp->file_mode)) {
+		dp->writeq = snd_seq_oss_writeq_new(dp, maxqlen);
+		if (!dp->writeq) {
+			rc = -ENOMEM;
+			goto _error;
+		}
+	}
+
+	/* initialize timer */
+	dp->timer = snd_seq_oss_timer_new(dp);
+	if (!dp->timer) {
+		pr_err("ALSA: seq_oss: can't alloc timer\n");
+		rc = -ENOMEM;
+		goto _error;
+	}
+
+	/* set private data pointer */
+	file->private_data = dp;
+
+	/* set up for mode2 */
+	if (level == SNDRV_SEQ_OSS_MODE_MUSIC)
+		snd_seq_oss_synth_setup_midi(dp);
+	else if (is_read_mode(dp->file_mode))
+		snd_seq_oss_midi_open_all(dp, SNDRV_SEQ_OSS_FILE_READ);
+
+	client_table[dp->index] = dp;
+	num_clients++;
+
+	return 0;
+
+ _error:
+	snd_seq_oss_synth_cleanup(dp);
+	snd_seq_oss_midi_cleanup(dp);
+	delete_seq_queue(dp->queue);
+	delete_port(dp);
+
+	return rc;
+}
+
+/*
+ * translate file flags to private mode
+ */
+static int
+translate_mode(struct file *file)
+{
+	int file_mode = 0;
+	if ((file->f_flags & O_ACCMODE) != O_RDONLY)
+		file_mode |= SNDRV_SEQ_OSS_FILE_WRITE;
+	if ((file->f_flags & O_ACCMODE) != O_WRONLY)
+		file_mode |= SNDRV_SEQ_OSS_FILE_READ;
+	if (file->f_flags & O_NONBLOCK)
+		file_mode |= SNDRV_SEQ_OSS_FILE_NONBLOCK;
+	return file_mode;
+}
+
+
+/*
+ * create sequencer port
+ */
+static int
+create_port(struct seq_oss_devinfo *dp)
+{
+	int rc;
+	struct snd_seq_port_info port;
+	struct snd_seq_port_callback callback;
+
+	memset(&port, 0, sizeof(port));
+	port.addr.client = dp->cseq;
+	sprintf(port.name, "Sequencer-%d", dp->index);
+	port.capability = SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_WRITE; /* no subscription */
+	port.type = SNDRV_SEQ_PORT_TYPE_SPECIFIC;
+	port.midi_channels = 128;
+	port.synth_voices = 128;
+
+	memset(&callback, 0, sizeof(callback));
+	callback.owner = THIS_MODULE;
+	callback.private_data = dp;
+	callback.event_input = snd_seq_oss_event_input;
+	callback.private_free = free_devinfo;
+	port.kernel = &callback;
+
+	rc = call_ctl(SNDRV_SEQ_IOCTL_CREATE_PORT, &port);
+	if (rc < 0)
+		return rc;
+
+	dp->port = port.addr.port;
+
+	return 0;
+}
+
+/*
+ * delete ALSA port
+ */
+static int
+delete_port(struct seq_oss_devinfo *dp)
+{
+	if (dp->port < 0) {
+		kfree(dp);
+		return 0;
+	}
+
+	return snd_seq_event_port_detach(dp->cseq, dp->port);
+}
+
+/*
+ * allocate a queue
+ */
+static int
+alloc_seq_queue(struct seq_oss_devinfo *dp)
+{
+	struct snd_seq_queue_info qinfo;
+	int rc;
+
+	memset(&qinfo, 0, sizeof(qinfo));
+	qinfo.owner = system_client;
+	qinfo.locked = 1;
+	strcpy(qinfo.name, "OSS Sequencer Emulation");
+	rc = call_ctl(SNDRV_SEQ_IOCTL_CREATE_QUEUE, &qinfo);
+	if (rc < 0)
+		return rc;
+	dp->queue = qinfo.queue;
+	return 0;
+}
+
+/*
+ * release queue
+ */
+static int
+delete_seq_queue(int queue)
+{
+	struct snd_seq_queue_info qinfo;
+	int rc;
+
+	if (queue < 0)
+		return 0;
+	memset(&qinfo, 0, sizeof(qinfo));
+	qinfo.queue = queue;
+	rc = call_ctl(SNDRV_SEQ_IOCTL_DELETE_QUEUE, &qinfo);
+	if (rc < 0)
+		pr_err("ALSA: seq_oss: unable to delete queue %d (%d)\n", queue, rc);
+	return rc;
+}
+
+
+/*
+ * free device informations - private_free callback of port
+ */
+static void
+free_devinfo(void *private)
+{
+	struct seq_oss_devinfo *dp = (struct seq_oss_devinfo *)private;
+
+	snd_seq_oss_timer_delete(dp->timer);
+		
+	snd_seq_oss_writeq_delete(dp->writeq);
+
+	snd_seq_oss_readq_delete(dp->readq);
+	
+	kfree(dp);
+}
+
+
+/*
+ * close sequencer device
+ */
+void
+snd_seq_oss_release(struct seq_oss_devinfo *dp)
+{
+	int queue;
+
+	client_table[dp->index] = NULL;
+	num_clients--;
+
+	snd_seq_oss_reset(dp);
+
+	snd_seq_oss_synth_cleanup(dp);
+	snd_seq_oss_midi_cleanup(dp);
+
+	/* clear slot */
+	queue = dp->queue;
+	if (dp->port >= 0)
+		delete_port(dp);
+	delete_seq_queue(queue);
+}
+
+
+/*
+ * reset sequencer devices
+ */
+void
+snd_seq_oss_reset(struct seq_oss_devinfo *dp)
+{
+	int i;
+
+	/* reset all synth devices */
+	for (i = 0; i < dp->max_synthdev; i++)
+		snd_seq_oss_synth_reset(dp, i);
+
+	/* reset all midi devices */
+	if (dp->seq_mode != SNDRV_SEQ_OSS_MODE_MUSIC) {
+		for (i = 0; i < dp->max_mididev; i++)
+			snd_seq_oss_midi_reset(dp, i);
+	}
+
+	/* remove queues */
+	if (dp->readq)
+		snd_seq_oss_readq_clear(dp->readq);
+	if (dp->writeq)
+		snd_seq_oss_writeq_clear(dp->writeq);
+
+	/* reset timer */
+	snd_seq_oss_timer_stop(dp->timer);
+}
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ * misc. functions for proc interface
+ */
+char *
+enabled_str(int bool)
+{
+	return bool ? "enabled" : "disabled";
+}
+
+static const char *
+filemode_str(int val)
+{
+	static const char * const str[] = {
+		"none", "read", "write", "read/write",
+	};
+	return str[val & SNDRV_SEQ_OSS_FILE_ACMODE];
+}
+
+
+/*
+ * proc interface
+ */
+void
+snd_seq_oss_system_info_read(struct snd_info_buffer *buf)
+{
+	int i;
+	struct seq_oss_devinfo *dp;
+
+	snd_iprintf(buf, "ALSA client number %d\n", system_client);
+	snd_iprintf(buf, "ALSA receiver port %d\n", system_port);
+
+	snd_iprintf(buf, "\nNumber of applications: %d\n", num_clients);
+	for (i = 0; i < num_clients; i++) {
+		snd_iprintf(buf, "\nApplication %d: ", i);
+		dp = client_table[i];
+		if (!dp) {
+			snd_iprintf(buf, "*empty*\n");
+			continue;
+		}
+		snd_iprintf(buf, "port %d : queue %d\n", dp->port, dp->queue);
+		snd_iprintf(buf, "  sequencer mode = %s : file open mode = %s\n",
+			    (dp->seq_mode ? "music" : "synth"),
+			    filemode_str(dp->file_mode));
+		if (dp->seq_mode)
+			snd_iprintf(buf, "  timer tempo = %d, timebase = %d\n",
+				    dp->timer->oss_tempo, dp->timer->oss_timebase);
+		snd_iprintf(buf, "  max queue length %d\n", maxqlen);
+		if (is_read_mode(dp->file_mode) && dp->readq)
+			snd_seq_oss_readq_info_read(dp->readq, buf);
+	}
+}
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/seq/oss/seq_oss_ioctl.c b/sound/core/seq/oss/seq_oss_ioctl.c
new file mode 100644
index 0000000000..ccf682689e
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_ioctl.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * OSS compatible i/o control
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_device.h"
+#include "seq_oss_readq.h"
+#include "seq_oss_writeq.h"
+#include "seq_oss_timer.h"
+#include "seq_oss_synth.h"
+#include "seq_oss_midi.h"
+#include "seq_oss_event.h"
+
+static int snd_seq_oss_synth_info_user(struct seq_oss_devinfo *dp, void __user *arg)
+{
+	struct synth_info info;
+
+	if (copy_from_user(&info, arg, sizeof(info)))
+		return -EFAULT;
+	if (snd_seq_oss_synth_make_info(dp, info.device, &info) < 0)
+		return -EINVAL;
+	if (copy_to_user(arg, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_seq_oss_midi_info_user(struct seq_oss_devinfo *dp, void __user *arg)
+{
+	struct midi_info info;
+
+	if (copy_from_user(&info, arg, sizeof(info)))
+		return -EFAULT;
+	if (snd_seq_oss_midi_make_info(dp, info.device, &info) < 0)
+		return -EINVAL;
+	if (copy_to_user(arg, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_seq_oss_oob_user(struct seq_oss_devinfo *dp, void __user *arg)
+{
+	unsigned char ev[8];
+	struct snd_seq_event tmpev;
+
+	if (copy_from_user(ev, arg, 8))
+		return -EFAULT;
+	memset(&tmpev, 0, sizeof(tmpev));
+	snd_seq_oss_fill_addr(dp, &tmpev, dp->addr.client, dp->addr.port);
+	tmpev.time.tick = 0;
+	if (! snd_seq_oss_process_event(dp, (union evrec *)ev, &tmpev)) {
+		snd_seq_oss_dispatch(dp, &tmpev, 0, 0);
+	}
+	return 0;
+}
+
+int
+snd_seq_oss_ioctl(struct seq_oss_devinfo *dp, unsigned int cmd, unsigned long carg)
+{
+	int dev, val;
+	void __user *arg = (void __user *)carg;
+	int __user *p = arg;
+
+	switch (cmd) {
+	case SNDCTL_TMR_TIMEBASE:
+	case SNDCTL_TMR_TEMPO:
+	case SNDCTL_TMR_START:
+	case SNDCTL_TMR_STOP:
+	case SNDCTL_TMR_CONTINUE:
+	case SNDCTL_TMR_METRONOME:
+	case SNDCTL_TMR_SOURCE:
+	case SNDCTL_TMR_SELECT:
+	case SNDCTL_SEQ_CTRLRATE:
+		return snd_seq_oss_timer_ioctl(dp->timer, cmd, arg);
+
+	case SNDCTL_SEQ_PANIC:
+		snd_seq_oss_reset(dp);
+		return -EINVAL;
+
+	case SNDCTL_SEQ_SYNC:
+		if (! is_write_mode(dp->file_mode) || dp->writeq == NULL)
+			return 0;
+		while (snd_seq_oss_writeq_sync(dp->writeq))
+			;
+		if (signal_pending(current))
+			return -ERESTARTSYS;
+		return 0;
+
+	case SNDCTL_SEQ_RESET:
+		snd_seq_oss_reset(dp);
+		return 0;
+
+	case SNDCTL_SEQ_TESTMIDI:
+		if (get_user(dev, p))
+			return -EFAULT;
+		return snd_seq_oss_midi_open(dp, dev, dp->file_mode);
+
+	case SNDCTL_SEQ_GETINCOUNT:
+		if (dp->readq == NULL || ! is_read_mode(dp->file_mode))
+			return 0;
+		return put_user(dp->readq->qlen, p) ? -EFAULT : 0;
+
+	case SNDCTL_SEQ_GETOUTCOUNT:
+		if (! is_write_mode(dp->file_mode) || dp->writeq == NULL)
+			return 0;
+		return put_user(snd_seq_oss_writeq_get_free_size(dp->writeq), p) ? -EFAULT : 0;
+
+	case SNDCTL_SEQ_GETTIME:
+		return put_user(snd_seq_oss_timer_cur_tick(dp->timer), p) ? -EFAULT : 0;
+
+	case SNDCTL_SEQ_RESETSAMPLES:
+		if (get_user(dev, p))
+			return -EFAULT;
+		return snd_seq_oss_synth_ioctl(dp, dev, cmd, carg);
+
+	case SNDCTL_SEQ_NRSYNTHS:
+		return put_user(dp->max_synthdev, p) ? -EFAULT : 0;
+
+	case SNDCTL_SEQ_NRMIDIS:
+		return put_user(dp->max_mididev, p) ? -EFAULT : 0;
+
+	case SNDCTL_SYNTH_MEMAVL:
+		if (get_user(dev, p))
+			return -EFAULT;
+		val = snd_seq_oss_synth_ioctl(dp, dev, cmd, carg);
+		return put_user(val, p) ? -EFAULT : 0;
+
+	case SNDCTL_FM_4OP_ENABLE:
+		if (get_user(dev, p))
+			return -EFAULT;
+		snd_seq_oss_synth_ioctl(dp, dev, cmd, carg);
+		return 0;
+
+	case SNDCTL_SYNTH_INFO:
+	case SNDCTL_SYNTH_ID:
+		return snd_seq_oss_synth_info_user(dp, arg);
+
+	case SNDCTL_SEQ_OUTOFBAND:
+		return snd_seq_oss_oob_user(dp, arg);
+
+	case SNDCTL_MIDI_INFO:
+		return snd_seq_oss_midi_info_user(dp, arg);
+
+	case SNDCTL_SEQ_THRESHOLD:
+		if (! is_write_mode(dp->file_mode))
+			return 0;
+		if (get_user(val, p))
+			return -EFAULT;
+		if (val < 1)
+			val = 1;
+		if (val >= dp->writeq->maxlen)
+			val = dp->writeq->maxlen - 1;
+		snd_seq_oss_writeq_set_output(dp->writeq, val);
+		return 0;
+
+	case SNDCTL_MIDI_PRETIME:
+		if (dp->readq == NULL || !is_read_mode(dp->file_mode))
+			return 0;
+		if (get_user(val, p))
+			return -EFAULT;
+		if (val <= 0)
+			val = -1;
+		else
+			val = (HZ * val) / 10;
+		dp->readq->pre_event_timeout = val;
+		return put_user(val, p) ? -EFAULT : 0;
+
+	default:
+		if (! is_write_mode(dp->file_mode))
+			return -EIO;
+		return snd_seq_oss_synth_ioctl(dp, 0, cmd, carg);
+	}
+	return 0;
+}
+
diff --git a/sound/core/seq/oss/seq_oss_midi.c b/sound/core/seq/oss/seq_oss_midi.c
new file mode 100644
index 0000000000..f2940b2959
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_midi.c
@@ -0,0 +1,718 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * MIDI device handlers
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <sound/asoundef.h>
+#include "seq_oss_midi.h"
+#include "seq_oss_readq.h"
+#include "seq_oss_timer.h"
+#include "seq_oss_event.h"
+#include <sound/seq_midi_event.h>
+#include "../seq_lock.h"
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/nospec.h>
+
+
+/*
+ * constants
+ */
+#define SNDRV_SEQ_OSS_MAX_MIDI_NAME	30
+
+/*
+ * definition of midi device record
+ */
+struct seq_oss_midi {
+	int seq_device;		/* device number */
+	int client;		/* sequencer client number */
+	int port;		/* sequencer port number */
+	unsigned int flags;	/* port capability */
+	int opened;		/* flag for opening */
+	unsigned char name[SNDRV_SEQ_OSS_MAX_MIDI_NAME];
+	struct snd_midi_event *coder;	/* MIDI event coder */
+	struct seq_oss_devinfo *devinfo;	/* assigned OSSseq device */
+	snd_use_lock_t use_lock;
+	struct mutex open_mutex;
+};
+
+
+/*
+ * midi device table
+ */
+static int max_midi_devs;
+static struct seq_oss_midi *midi_devs[SNDRV_SEQ_OSS_MAX_MIDI_DEVS];
+
+static DEFINE_SPINLOCK(register_lock);
+
+/*
+ * prototypes
+ */
+static struct seq_oss_midi *get_mdev(int dev);
+static struct seq_oss_midi *get_mididev(struct seq_oss_devinfo *dp, int dev);
+static int send_synth_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, int dev);
+static int send_midi_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, struct seq_oss_midi *mdev);
+
+/*
+ * look up the existing ports
+ * this looks a very exhausting job.
+ */
+int
+snd_seq_oss_midi_lookup_ports(int client)
+{
+	struct snd_seq_client_info *clinfo;
+	struct snd_seq_port_info *pinfo;
+
+	clinfo = kzalloc(sizeof(*clinfo), GFP_KERNEL);
+	pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
+	if (! clinfo || ! pinfo) {
+		kfree(clinfo);
+		kfree(pinfo);
+		return -ENOMEM;
+	}
+	clinfo->client = -1;
+	while (snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT, clinfo) == 0) {
+		if (clinfo->client == client)
+			continue; /* ignore myself */
+		pinfo->addr.client = clinfo->client;
+		pinfo->addr.port = -1;
+		while (snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, pinfo) == 0)
+			snd_seq_oss_midi_check_new_port(pinfo);
+	}
+	kfree(clinfo);
+	kfree(pinfo);
+	return 0;
+}
+
+
+/*
+ */
+static struct seq_oss_midi *
+get_mdev(int dev)
+{
+	struct seq_oss_midi *mdev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&register_lock, flags);
+	mdev = midi_devs[dev];
+	if (mdev)
+		snd_use_lock_use(&mdev->use_lock);
+	spin_unlock_irqrestore(&register_lock, flags);
+	return mdev;
+}
+
+/*
+ * look for the identical slot
+ */
+static struct seq_oss_midi *
+find_slot(int client, int port)
+{
+	int i;
+	struct seq_oss_midi *mdev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&register_lock, flags);
+	for (i = 0; i < max_midi_devs; i++) {
+		mdev = midi_devs[i];
+		if (mdev && mdev->client == client && mdev->port == port) {
+			/* found! */
+			snd_use_lock_use(&mdev->use_lock);
+			spin_unlock_irqrestore(&register_lock, flags);
+			return mdev;
+		}
+	}
+	spin_unlock_irqrestore(&register_lock, flags);
+	return NULL;
+}
+
+
+#define PERM_WRITE (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_SUBS_WRITE)
+#define PERM_READ (SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ)
+/*
+ * register a new port if it doesn't exist yet
+ */
+int
+snd_seq_oss_midi_check_new_port(struct snd_seq_port_info *pinfo)
+{
+	int i;
+	struct seq_oss_midi *mdev;
+	unsigned long flags;
+
+	/* the port must include generic midi */
+	if (! (pinfo->type & SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC))
+		return 0;
+	/* either read or write subscribable */
+	if ((pinfo->capability & PERM_WRITE) != PERM_WRITE &&
+	    (pinfo->capability & PERM_READ) != PERM_READ)
+		return 0;
+
+	/*
+	 * look for the identical slot
+	 */
+	mdev = find_slot(pinfo->addr.client, pinfo->addr.port);
+	if (mdev) {
+		/* already exists */
+		snd_use_lock_free(&mdev->use_lock);
+		return 0;
+	}
+
+	/*
+	 * allocate midi info record
+	 */
+	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return -ENOMEM;
+
+	/* copy the port information */
+	mdev->client = pinfo->addr.client;
+	mdev->port = pinfo->addr.port;
+	mdev->flags = pinfo->capability;
+	mdev->opened = 0;
+	snd_use_lock_init(&mdev->use_lock);
+	mutex_init(&mdev->open_mutex);
+
+	/* copy and truncate the name of synth device */
+	strscpy(mdev->name, pinfo->name, sizeof(mdev->name));
+
+	/* create MIDI coder */
+	if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &mdev->coder) < 0) {
+		pr_err("ALSA: seq_oss: can't malloc midi coder\n");
+		kfree(mdev);
+		return -ENOMEM;
+	}
+	/* OSS sequencer adds running status to all sequences */
+	snd_midi_event_no_status(mdev->coder, 1);
+
+	/*
+	 * look for en empty slot
+	 */
+	spin_lock_irqsave(&register_lock, flags);
+	for (i = 0; i < max_midi_devs; i++) {
+		if (midi_devs[i] == NULL)
+			break;
+	}
+	if (i >= max_midi_devs) {
+		if (max_midi_devs >= SNDRV_SEQ_OSS_MAX_MIDI_DEVS) {
+			spin_unlock_irqrestore(&register_lock, flags);
+			snd_midi_event_free(mdev->coder);
+			kfree(mdev);
+			return -ENOMEM;
+		}
+		max_midi_devs++;
+	}
+	mdev->seq_device = i;
+	midi_devs[mdev->seq_device] = mdev;
+	spin_unlock_irqrestore(&register_lock, flags);
+
+	return 0;
+}
+
+/*
+ * release the midi device if it was registered
+ */
+int
+snd_seq_oss_midi_check_exit_port(int client, int port)
+{
+	struct seq_oss_midi *mdev;
+	unsigned long flags;
+	int index;
+
+	mdev = find_slot(client, port);
+	if (mdev) {
+		spin_lock_irqsave(&register_lock, flags);
+		midi_devs[mdev->seq_device] = NULL;
+		spin_unlock_irqrestore(&register_lock, flags);
+		snd_use_lock_free(&mdev->use_lock);
+		snd_use_lock_sync(&mdev->use_lock);
+		snd_midi_event_free(mdev->coder);
+		kfree(mdev);
+	}
+	spin_lock_irqsave(&register_lock, flags);
+	for (index = max_midi_devs - 1; index >= 0; index--) {
+		if (midi_devs[index])
+			break;
+	}
+	max_midi_devs = index + 1;
+	spin_unlock_irqrestore(&register_lock, flags);
+	return 0;
+}
+
+
+/*
+ * release the midi device if it was registered
+ */
+void
+snd_seq_oss_midi_clear_all(void)
+{
+	int i;
+	struct seq_oss_midi *mdev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&register_lock, flags);
+	for (i = 0; i < max_midi_devs; i++) {
+		mdev = midi_devs[i];
+		if (mdev) {
+			snd_midi_event_free(mdev->coder);
+			kfree(mdev);
+			midi_devs[i] = NULL;
+		}
+	}
+	max_midi_devs = 0;
+	spin_unlock_irqrestore(&register_lock, flags);
+}
+
+
+/*
+ * set up midi tables
+ */
+void
+snd_seq_oss_midi_setup(struct seq_oss_devinfo *dp)
+{
+	spin_lock_irq(&register_lock);
+	dp->max_mididev = max_midi_devs;
+	spin_unlock_irq(&register_lock);
+}
+
+/*
+ * clean up midi tables
+ */
+void
+snd_seq_oss_midi_cleanup(struct seq_oss_devinfo *dp)
+{
+	int i;
+	for (i = 0; i < dp->max_mididev; i++)
+		snd_seq_oss_midi_close(dp, i);
+	dp->max_mididev = 0;
+}
+
+
+/*
+ * open all midi devices.  ignore errors.
+ */
+void
+snd_seq_oss_midi_open_all(struct seq_oss_devinfo *dp, int file_mode)
+{
+	int i;
+	for (i = 0; i < dp->max_mididev; i++)
+		snd_seq_oss_midi_open(dp, i, file_mode);
+}
+
+
+/*
+ * get the midi device information
+ */
+static struct seq_oss_midi *
+get_mididev(struct seq_oss_devinfo *dp, int dev)
+{
+	if (dev < 0 || dev >= dp->max_mididev)
+		return NULL;
+	dev = array_index_nospec(dev, dp->max_mididev);
+	return get_mdev(dev);
+}
+
+
+/*
+ * open the midi device if not opened yet
+ */
+int
+snd_seq_oss_midi_open(struct seq_oss_devinfo *dp, int dev, int fmode)
+{
+	int perm;
+	struct seq_oss_midi *mdev;
+	struct snd_seq_port_subscribe subs;
+	int err;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return -ENODEV;
+
+	mutex_lock(&mdev->open_mutex);
+	/* already used? */
+	if (mdev->opened && mdev->devinfo != dp) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	perm = 0;
+	if (is_write_mode(fmode))
+		perm |= PERM_WRITE;
+	if (is_read_mode(fmode))
+		perm |= PERM_READ;
+	perm &= mdev->flags;
+	if (perm == 0) {
+		err = -ENXIO;
+		goto unlock;
+	}
+
+	/* already opened? */
+	if ((mdev->opened & perm) == perm) {
+		err = 0;
+		goto unlock;
+	}
+
+	perm &= ~mdev->opened;
+
+	memset(&subs, 0, sizeof(subs));
+
+	if (perm & PERM_WRITE) {
+		subs.sender = dp->addr;
+		subs.dest.client = mdev->client;
+		subs.dest.port = mdev->port;
+		if (snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, &subs) >= 0)
+			mdev->opened |= PERM_WRITE;
+	}
+	if (perm & PERM_READ) {
+		subs.sender.client = mdev->client;
+		subs.sender.port = mdev->port;
+		subs.dest = dp->addr;
+		subs.flags = SNDRV_SEQ_PORT_SUBS_TIMESTAMP;
+		subs.queue = dp->queue;		/* queue for timestamps */
+		if (snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, &subs) >= 0)
+			mdev->opened |= PERM_READ;
+	}
+
+	if (! mdev->opened) {
+		err = -ENXIO;
+		goto unlock;
+	}
+
+	mdev->devinfo = dp;
+	err = 0;
+
+ unlock:
+	mutex_unlock(&mdev->open_mutex);
+	snd_use_lock_free(&mdev->use_lock);
+	return err;
+}
+
+/*
+ * close the midi device if already opened
+ */
+int
+snd_seq_oss_midi_close(struct seq_oss_devinfo *dp, int dev)
+{
+	struct seq_oss_midi *mdev;
+	struct snd_seq_port_subscribe subs;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return -ENODEV;
+	mutex_lock(&mdev->open_mutex);
+	if (!mdev->opened || mdev->devinfo != dp)
+		goto unlock;
+
+	memset(&subs, 0, sizeof(subs));
+	if (mdev->opened & PERM_WRITE) {
+		subs.sender = dp->addr;
+		subs.dest.client = mdev->client;
+		subs.dest.port = mdev->port;
+		snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, &subs);
+	}
+	if (mdev->opened & PERM_READ) {
+		subs.sender.client = mdev->client;
+		subs.sender.port = mdev->port;
+		subs.dest = dp->addr;
+		snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, &subs);
+	}
+
+	mdev->opened = 0;
+	mdev->devinfo = NULL;
+
+ unlock:
+	mutex_unlock(&mdev->open_mutex);
+	snd_use_lock_free(&mdev->use_lock);
+	return 0;
+}
+
+/*
+ * change seq capability flags to file mode flags
+ */
+int
+snd_seq_oss_midi_filemode(struct seq_oss_devinfo *dp, int dev)
+{
+	struct seq_oss_midi *mdev;
+	int mode;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return 0;
+
+	mode = 0;
+	if (mdev->opened & PERM_WRITE)
+		mode |= SNDRV_SEQ_OSS_FILE_WRITE;
+	if (mdev->opened & PERM_READ)
+		mode |= SNDRV_SEQ_OSS_FILE_READ;
+
+	snd_use_lock_free(&mdev->use_lock);
+	return mode;
+}
+
+/*
+ * reset the midi device and close it:
+ * so far, only close the device.
+ */
+void
+snd_seq_oss_midi_reset(struct seq_oss_devinfo *dp, int dev)
+{
+	struct seq_oss_midi *mdev;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return;
+	if (! mdev->opened) {
+		snd_use_lock_free(&mdev->use_lock);
+		return;
+	}
+
+	if (mdev->opened & PERM_WRITE) {
+		struct snd_seq_event ev;
+		int c;
+
+		memset(&ev, 0, sizeof(ev));
+		ev.dest.client = mdev->client;
+		ev.dest.port = mdev->port;
+		ev.queue = dp->queue;
+		ev.source.port = dp->port;
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH) {
+			ev.type = SNDRV_SEQ_EVENT_SENSING;
+			snd_seq_oss_dispatch(dp, &ev, 0, 0);
+		}
+		for (c = 0; c < 16; c++) {
+			ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
+			ev.data.control.channel = c;
+			ev.data.control.param = MIDI_CTL_ALL_NOTES_OFF;
+			snd_seq_oss_dispatch(dp, &ev, 0, 0);
+			if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
+				ev.data.control.param =
+					MIDI_CTL_RESET_CONTROLLERS;
+				snd_seq_oss_dispatch(dp, &ev, 0, 0);
+				ev.type = SNDRV_SEQ_EVENT_PITCHBEND;
+				ev.data.control.value = 0;
+				snd_seq_oss_dispatch(dp, &ev, 0, 0);
+			}
+		}
+	}
+	// snd_seq_oss_midi_close(dp, dev);
+	snd_use_lock_free(&mdev->use_lock);
+}
+
+
+/*
+ * get client/port of the specified MIDI device
+ */
+void
+snd_seq_oss_midi_get_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_addr *addr)
+{
+	struct seq_oss_midi *mdev;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return;
+	addr->client = mdev->client;
+	addr->port = mdev->port;
+	snd_use_lock_free(&mdev->use_lock);
+}
+
+
+/*
+ * input callback - this can be atomic
+ */
+int
+snd_seq_oss_midi_input(struct snd_seq_event *ev, int direct, void *private_data)
+{
+	struct seq_oss_devinfo *dp = (struct seq_oss_devinfo *)private_data;
+	struct seq_oss_midi *mdev;
+	int rc;
+
+	if (dp->readq == NULL)
+		return 0;
+	mdev = find_slot(ev->source.client, ev->source.port);
+	if (!mdev)
+		return 0;
+	if (! (mdev->opened & PERM_READ)) {
+		snd_use_lock_free(&mdev->use_lock);
+		return 0;
+	}
+
+	if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
+		rc = send_synth_event(dp, ev, mdev->seq_device);
+	else
+		rc = send_midi_event(dp, ev, mdev);
+
+	snd_use_lock_free(&mdev->use_lock);
+	return rc;
+}
+
+/*
+ * convert ALSA sequencer event to OSS synth event
+ */
+static int
+send_synth_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, int dev)
+{
+	union evrec ossev;
+
+	memset(&ossev, 0, sizeof(ossev));
+
+	switch (ev->type) {
+	case SNDRV_SEQ_EVENT_NOTEON:
+		ossev.v.cmd = MIDI_NOTEON; break;
+	case SNDRV_SEQ_EVENT_NOTEOFF:
+		ossev.v.cmd = MIDI_NOTEOFF; break;
+	case SNDRV_SEQ_EVENT_KEYPRESS:
+		ossev.v.cmd = MIDI_KEY_PRESSURE; break;
+	case SNDRV_SEQ_EVENT_CONTROLLER:
+		ossev.l.cmd = MIDI_CTL_CHANGE; break;
+	case SNDRV_SEQ_EVENT_PGMCHANGE:
+		ossev.l.cmd = MIDI_PGM_CHANGE; break;
+	case SNDRV_SEQ_EVENT_CHANPRESS:
+		ossev.l.cmd = MIDI_CHN_PRESSURE; break;
+	case SNDRV_SEQ_EVENT_PITCHBEND:
+		ossev.l.cmd = MIDI_PITCH_BEND; break;
+	default:
+		return 0; /* not supported */
+	}
+
+	ossev.v.dev = dev;
+
+	switch (ev->type) {
+	case SNDRV_SEQ_EVENT_NOTEON:
+	case SNDRV_SEQ_EVENT_NOTEOFF:
+	case SNDRV_SEQ_EVENT_KEYPRESS:
+		ossev.v.code = EV_CHN_VOICE;
+		ossev.v.note = ev->data.note.note;
+		ossev.v.parm = ev->data.note.velocity;
+		ossev.v.chn = ev->data.note.channel;
+		break;
+	case SNDRV_SEQ_EVENT_CONTROLLER:
+	case SNDRV_SEQ_EVENT_PGMCHANGE:
+	case SNDRV_SEQ_EVENT_CHANPRESS:
+		ossev.l.code = EV_CHN_COMMON;
+		ossev.l.p1 = ev->data.control.param;
+		ossev.l.val = ev->data.control.value;
+		ossev.l.chn = ev->data.control.channel;
+		break;
+	case SNDRV_SEQ_EVENT_PITCHBEND:
+		ossev.l.code = EV_CHN_COMMON;
+		ossev.l.val = ev->data.control.value + 8192;
+		ossev.l.chn = ev->data.control.channel;
+		break;
+	}
+	
+	snd_seq_oss_readq_put_timestamp(dp->readq, ev->time.tick, dp->seq_mode);
+	snd_seq_oss_readq_put_event(dp->readq, &ossev);
+
+	return 0;
+}
+
+/*
+ * decode event and send MIDI bytes to read queue
+ */
+static int
+send_midi_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, struct seq_oss_midi *mdev)
+{
+	char msg[32];
+	int len;
+	
+	snd_seq_oss_readq_put_timestamp(dp->readq, ev->time.tick, dp->seq_mode);
+	if (!dp->timer->running)
+		len = snd_seq_oss_timer_start(dp->timer);
+	if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
+		snd_seq_oss_readq_sysex(dp->readq, mdev->seq_device, ev);
+		snd_midi_event_reset_decode(mdev->coder);
+	} else {
+		len = snd_midi_event_decode(mdev->coder, msg, sizeof(msg), ev);
+		if (len > 0)
+			snd_seq_oss_readq_puts(dp->readq, mdev->seq_device, msg, len);
+	}
+
+	return 0;
+}
+
+
+/*
+ * dump midi data
+ * return 0 : enqueued
+ *        non-zero : invalid - ignored
+ */
+int
+snd_seq_oss_midi_putc(struct seq_oss_devinfo *dp, int dev, unsigned char c, struct snd_seq_event *ev)
+{
+	struct seq_oss_midi *mdev;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return -ENODEV;
+	if (snd_midi_event_encode_byte(mdev->coder, c, ev)) {
+		snd_seq_oss_fill_addr(dp, ev, mdev->client, mdev->port);
+		snd_use_lock_free(&mdev->use_lock);
+		return 0;
+	}
+	snd_use_lock_free(&mdev->use_lock);
+	return -EINVAL;
+}
+
+/*
+ * create OSS compatible midi_info record
+ */
+int
+snd_seq_oss_midi_make_info(struct seq_oss_devinfo *dp, int dev, struct midi_info *inf)
+{
+	struct seq_oss_midi *mdev;
+
+	mdev = get_mididev(dp, dev);
+	if (!mdev)
+		return -ENXIO;
+	inf->device = dev;
+	inf->dev_type = 0; /* FIXME: ?? */
+	inf->capabilities = 0; /* FIXME: ?? */
+	strscpy(inf->name, mdev->name, sizeof(inf->name));
+	snd_use_lock_free(&mdev->use_lock);
+	return 0;
+}
+
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ * proc interface
+ */
+static char *
+capmode_str(int val)
+{
+	val &= PERM_READ|PERM_WRITE;
+	if (val == (PERM_READ|PERM_WRITE))
+		return "read/write";
+	else if (val == PERM_READ)
+		return "read";
+	else if (val == PERM_WRITE)
+		return "write";
+	else
+		return "none";
+}
+
+void
+snd_seq_oss_midi_info_read(struct snd_info_buffer *buf)
+{
+	int i;
+	struct seq_oss_midi *mdev;
+
+	snd_iprintf(buf, "\nNumber of MIDI devices: %d\n", max_midi_devs);
+	for (i = 0; i < max_midi_devs; i++) {
+		snd_iprintf(buf, "\nmidi %d: ", i);
+		mdev = get_mdev(i);
+		if (mdev == NULL) {
+			snd_iprintf(buf, "*empty*\n");
+			continue;
+		}
+		snd_iprintf(buf, "[%s] ALSA port %d:%d\n", mdev->name,
+			    mdev->client, mdev->port);
+		snd_iprintf(buf, "  capability %s / opened %s\n",
+			    capmode_str(mdev->flags),
+			    capmode_str(mdev->opened));
+		snd_use_lock_free(&mdev->use_lock);
+	}
+}
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/seq/oss/seq_oss_midi.h b/sound/core/seq/oss/seq_oss_midi.h
new file mode 100644
index 0000000000..bcc1683773
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_midi.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ *
+ * midi device information
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_MIDI_H
+#define __SEQ_OSS_MIDI_H
+
+#include "seq_oss_device.h"
+#include <sound/seq_oss_legacy.h>
+
+int snd_seq_oss_midi_lookup_ports(int client);
+int snd_seq_oss_midi_check_new_port(struct snd_seq_port_info *pinfo);
+int snd_seq_oss_midi_check_exit_port(int client, int port);
+void snd_seq_oss_midi_clear_all(void);
+
+void snd_seq_oss_midi_setup(struct seq_oss_devinfo *dp);
+void snd_seq_oss_midi_cleanup(struct seq_oss_devinfo *dp);
+
+int snd_seq_oss_midi_open(struct seq_oss_devinfo *dp, int dev, int file_mode);
+void snd_seq_oss_midi_open_all(struct seq_oss_devinfo *dp, int file_mode);
+int snd_seq_oss_midi_close(struct seq_oss_devinfo *dp, int dev);
+void snd_seq_oss_midi_reset(struct seq_oss_devinfo *dp, int dev);
+int snd_seq_oss_midi_putc(struct seq_oss_devinfo *dp, int dev, unsigned char c,
+			  struct snd_seq_event *ev);
+int snd_seq_oss_midi_input(struct snd_seq_event *ev, int direct, void *private);
+int snd_seq_oss_midi_filemode(struct seq_oss_devinfo *dp, int dev);
+int snd_seq_oss_midi_make_info(struct seq_oss_devinfo *dp, int dev, struct midi_info *inf);
+void snd_seq_oss_midi_get_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_addr *addr);
+
+#endif
diff --git a/sound/core/seq/oss/seq_oss_readq.c b/sound/core/seq/oss/seq_oss_readq.c
new file mode 100644
index 0000000000..f0db5d3dcb
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_readq.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * seq_oss_readq.c - MIDI input queue
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_readq.h"
+#include "seq_oss_event.h"
+#include <sound/seq_oss_legacy.h>
+#include "../seq_lock.h"
+#include <linux/wait.h>
+#include <linux/slab.h>
+
+/*
+ * constants
+ */
+//#define SNDRV_SEQ_OSS_MAX_TIMEOUT	(unsigned long)(-1)
+#define SNDRV_SEQ_OSS_MAX_TIMEOUT	(HZ * 3600)
+
+
+/*
+ * prototypes
+ */
+
+
+/*
+ * create a read queue
+ */
+struct seq_oss_readq *
+snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen)
+{
+	struct seq_oss_readq *q;
+
+	q = kzalloc(sizeof(*q), GFP_KERNEL);
+	if (!q)
+		return NULL;
+
+	q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL);
+	if (!q->q) {
+		kfree(q);
+		return NULL;
+	}
+
+	q->maxlen = maxlen;
+	q->qlen = 0;
+	q->head = q->tail = 0;
+	init_waitqueue_head(&q->midi_sleep);
+	spin_lock_init(&q->lock);
+	q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;
+	q->input_time = (unsigned long)-1;
+
+	return q;
+}
+
+/*
+ * delete the read queue
+ */
+void
+snd_seq_oss_readq_delete(struct seq_oss_readq *q)
+{
+	if (q) {
+		kfree(q->q);
+		kfree(q);
+	}
+}
+
+/*
+ * reset the read queue
+ */
+void
+snd_seq_oss_readq_clear(struct seq_oss_readq *q)
+{
+	if (q->qlen) {
+		q->qlen = 0;
+		q->head = q->tail = 0;
+	}
+	/* if someone sleeping, wake'em up */
+	wake_up(&q->midi_sleep);
+	q->input_time = (unsigned long)-1;
+}
+
+/*
+ * put a midi byte
+ */
+int
+snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len)
+{
+	union evrec rec;
+	int result;
+
+	memset(&rec, 0, sizeof(rec));
+	rec.c[0] = SEQ_MIDIPUTC;
+	rec.c[2] = dev;
+
+	while (len-- > 0) {
+		rec.c[1] = *data++;
+		result = snd_seq_oss_readq_put_event(q, &rec);
+		if (result < 0)
+			return result;
+	}
+	return 0;
+}
+
+/*
+ * put MIDI sysex bytes; the event buffer may be chained, thus it has
+ * to be expanded via snd_seq_dump_var_event().
+ */
+struct readq_sysex_ctx {
+	struct seq_oss_readq *readq;
+	int dev;
+};
+
+static int readq_dump_sysex(void *ptr, void *buf, int count)
+{
+	struct readq_sysex_ctx *ctx = ptr;
+
+	return snd_seq_oss_readq_puts(ctx->readq, ctx->dev, buf, count);
+}
+
+int snd_seq_oss_readq_sysex(struct seq_oss_readq *q, int dev,
+			    struct snd_seq_event *ev)
+{
+	struct readq_sysex_ctx ctx = {
+		.readq = q,
+		.dev = dev
+	};
+
+	if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
+		return 0;
+	return snd_seq_dump_var_event(ev, readq_dump_sysex, &ctx);
+}
+
+/*
+ * copy an event to input queue:
+ * return zero if enqueued
+ */
+int
+snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->lock, flags);
+	if (q->qlen >= q->maxlen - 1) {
+		spin_unlock_irqrestore(&q->lock, flags);
+		return -ENOMEM;
+	}
+
+	memcpy(&q->q[q->tail], ev, sizeof(*ev));
+	q->tail = (q->tail + 1) % q->maxlen;
+	q->qlen++;
+
+	/* wake up sleeper */
+	wake_up(&q->midi_sleep);
+
+	spin_unlock_irqrestore(&q->lock, flags);
+
+	return 0;
+}
+
+
+/*
+ * pop queue
+ * caller must hold lock
+ */
+int
+snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)
+{
+	if (q->qlen == 0)
+		return -EAGAIN;
+	memcpy(rec, &q->q[q->head], sizeof(*rec));
+	return 0;
+}
+
+/*
+ * sleep until ready
+ */
+void
+snd_seq_oss_readq_wait(struct seq_oss_readq *q)
+{
+	wait_event_interruptible_timeout(q->midi_sleep,
+					 (q->qlen > 0 || q->head == q->tail),
+					 q->pre_event_timeout);
+}
+
+/*
+ * drain one record
+ * caller must hold lock
+ */
+void
+snd_seq_oss_readq_free(struct seq_oss_readq *q)
+{
+	if (q->qlen > 0) {
+		q->head = (q->head + 1) % q->maxlen;
+		q->qlen--;
+	}
+}
+
+/*
+ * polling/select:
+ * return non-zero if readq is not empty.
+ */
+unsigned int
+snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)
+{
+	poll_wait(file, &q->midi_sleep, wait);
+	return q->qlen;
+}
+
+/*
+ * put a timestamp
+ */
+int
+snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)
+{
+	if (curt != q->input_time) {
+		union evrec rec;
+		memset(&rec, 0, sizeof(rec));
+		switch (seq_mode) {
+		case SNDRV_SEQ_OSS_MODE_SYNTH:
+			rec.echo = (curt << 8) | SEQ_WAIT;
+			snd_seq_oss_readq_put_event(q, &rec);
+			break;
+		case SNDRV_SEQ_OSS_MODE_MUSIC:
+			rec.t.code = EV_TIMING;
+			rec.t.cmd = TMR_WAIT_ABS;
+			rec.t.time = curt;
+			snd_seq_oss_readq_put_event(q, &rec);
+			break;
+		}
+		q->input_time = curt;
+	}
+	return 0;
+}
+
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ * proc interface
+ */
+void
+snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)
+{
+	snd_iprintf(buf, "  read queue [%s] length = %d : tick = %ld\n",
+		    (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
+		    q->qlen, q->input_time);
+}
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/seq/oss/seq_oss_readq.h b/sound/core/seq/oss/seq_oss_readq.h
new file mode 100644
index 0000000000..38d0c4682b
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_readq.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ * read fifo queue
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_READQ_H
+#define __SEQ_OSS_READQ_H
+
+#include "seq_oss_device.h"
+
+
+/*
+ * definition of read queue
+ */
+struct seq_oss_readq {
+	union evrec *q;
+	int qlen;
+	int maxlen;
+	int head, tail;
+	unsigned long pre_event_timeout;
+	unsigned long input_time;
+	wait_queue_head_t midi_sleep;
+	spinlock_t lock;
+};
+
+struct seq_oss_readq *snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen);
+void snd_seq_oss_readq_delete(struct seq_oss_readq *q);
+void snd_seq_oss_readq_clear(struct seq_oss_readq *readq);
+unsigned int snd_seq_oss_readq_poll(struct seq_oss_readq *readq, struct file *file, poll_table *wait);
+int snd_seq_oss_readq_puts(struct seq_oss_readq *readq, int dev, unsigned char *data, int len);
+int snd_seq_oss_readq_sysex(struct seq_oss_readq *q, int dev,
+			    struct snd_seq_event *ev);
+int snd_seq_oss_readq_put_event(struct seq_oss_readq *readq, union evrec *ev);
+int snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *readq, unsigned long curt, int seq_mode);
+int snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec);
+void snd_seq_oss_readq_wait(struct seq_oss_readq *q);
+void snd_seq_oss_readq_free(struct seq_oss_readq *q);
+
+#define snd_seq_oss_readq_lock(q, flags) spin_lock_irqsave(&(q)->lock, flags)
+#define snd_seq_oss_readq_unlock(q, flags) spin_unlock_irqrestore(&(q)->lock, flags)
+
+#endif
diff --git a/sound/core/seq/oss/seq_oss_rw.c b/sound/core/seq/oss/seq_oss_rw.c
new file mode 100644
index 0000000000..8a142fd54a
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_rw.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * read/write/select interface to device file
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_device.h"
+#include "seq_oss_readq.h"
+#include "seq_oss_writeq.h"
+#include "seq_oss_synth.h"
+#include <sound/seq_oss_legacy.h>
+#include "seq_oss_event.h"
+#include "seq_oss_timer.h"
+#include "../seq_clientmgr.h"
+
+
+/*
+ * protoypes
+ */
+static int insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt);
+
+
+/*
+ * read interface
+ */
+
+int
+snd_seq_oss_read(struct seq_oss_devinfo *dp, char __user *buf, int count)
+{
+	struct seq_oss_readq *readq = dp->readq;
+	int result = 0, err = 0;
+	int ev_len;
+	union evrec rec;
+	unsigned long flags;
+
+	if (readq == NULL || ! is_read_mode(dp->file_mode))
+		return -ENXIO;
+
+	while (count >= SHORT_EVENT_SIZE) {
+		snd_seq_oss_readq_lock(readq, flags);
+		err = snd_seq_oss_readq_pick(readq, &rec);
+		if (err == -EAGAIN &&
+		    !is_nonblock_mode(dp->file_mode) && result == 0) {
+			snd_seq_oss_readq_unlock(readq, flags);
+			snd_seq_oss_readq_wait(readq);
+			snd_seq_oss_readq_lock(readq, flags);
+			if (signal_pending(current))
+				err = -ERESTARTSYS;
+			else
+				err = snd_seq_oss_readq_pick(readq, &rec);
+		}
+		if (err < 0) {
+			snd_seq_oss_readq_unlock(readq, flags);
+			break;
+		}
+		ev_len = ev_length(&rec);
+		if (ev_len < count) {
+			snd_seq_oss_readq_unlock(readq, flags);
+			break;
+		}
+		snd_seq_oss_readq_free(readq);
+		snd_seq_oss_readq_unlock(readq, flags);
+		if (copy_to_user(buf, &rec, ev_len)) {
+			err = -EFAULT;
+			break;
+		}
+		result += ev_len;
+		buf += ev_len;
+		count -= ev_len;
+	}
+	return result > 0 ? result : err;
+}
+
+
+/*
+ * write interface
+ */
+
+int
+snd_seq_oss_write(struct seq_oss_devinfo *dp, const char __user *buf, int count, struct file *opt)
+{
+	int result = 0, err = 0;
+	int ev_size, fmt;
+	union evrec rec;
+
+	if (! is_write_mode(dp->file_mode) || dp->writeq == NULL)
+		return -ENXIO;
+
+	while (count >= SHORT_EVENT_SIZE) {
+		if (copy_from_user(&rec, buf, SHORT_EVENT_SIZE)) {
+			err = -EFAULT;
+			break;
+		}
+		if (rec.s.code == SEQ_FULLSIZE) {
+			/* load patch */
+			if (result > 0) {
+				err = -EINVAL;
+				break;
+			}
+			fmt = (*(unsigned short *)rec.c) & 0xffff;
+			/* FIXME the return value isn't correct */
+			return snd_seq_oss_synth_load_patch(dp, rec.s.dev,
+							    fmt, buf, 0, count);
+		}
+		if (ev_is_long(&rec)) {
+			/* extended code */
+			if (rec.s.code == SEQ_EXTENDED &&
+			    dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
+				err = -EINVAL;
+				break;
+			}
+			ev_size = LONG_EVENT_SIZE;
+			if (count < ev_size)
+				break;
+			/* copy the reset 4 bytes */
+			if (copy_from_user(rec.c + SHORT_EVENT_SIZE,
+					   buf + SHORT_EVENT_SIZE,
+					   LONG_EVENT_SIZE - SHORT_EVENT_SIZE)) {
+				err = -EFAULT;
+				break;
+			}
+		} else {
+			/* old-type code */
+			if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
+				err = -EINVAL;
+				break;
+			}
+			ev_size = SHORT_EVENT_SIZE;
+		}
+
+		/* insert queue */
+		err = insert_queue(dp, &rec, opt);
+		if (err < 0)
+			break;
+
+		result += ev_size;
+		buf += ev_size;
+		count -= ev_size;
+	}
+	return result > 0 ? result : err;
+}
+
+
+/*
+ * insert event record to write queue
+ * return: 0 = OK, non-zero = NG
+ */
+static int
+insert_queue(struct seq_oss_devinfo *dp, union evrec *rec, struct file *opt)
+{
+	int rc = 0;
+	struct snd_seq_event event;
+
+	/* if this is a timing event, process the current time */
+	if (snd_seq_oss_process_timer_event(dp->timer, rec))
+		return 0; /* no need to insert queue */
+
+	/* parse this event */
+	memset(&event, 0, sizeof(event));
+	/* set dummy -- to be sure */
+	event.type = SNDRV_SEQ_EVENT_NOTEOFF;
+	snd_seq_oss_fill_addr(dp, &event, dp->addr.client, dp->addr.port);
+
+	if (snd_seq_oss_process_event(dp, rec, &event))
+		return 0; /* invalid event - no need to insert queue */
+
+	event.time.tick = snd_seq_oss_timer_cur_tick(dp->timer);
+	if (dp->timer->realtime || !dp->timer->running)
+		snd_seq_oss_dispatch(dp, &event, 0, 0);
+	else
+		rc = snd_seq_kernel_client_enqueue(dp->cseq, &event, opt,
+						   !is_nonblock_mode(dp->file_mode));
+	return rc;
+}
+		
+
+/*
+ * select / poll
+ */
+  
+__poll_t
+snd_seq_oss_poll(struct seq_oss_devinfo *dp, struct file *file, poll_table * wait)
+{
+	__poll_t mask = 0;
+
+	/* input */
+	if (dp->readq && is_read_mode(dp->file_mode)) {
+		if (snd_seq_oss_readq_poll(dp->readq, file, wait))
+			mask |= EPOLLIN | EPOLLRDNORM;
+	}
+
+	/* output */
+	if (dp->writeq && is_write_mode(dp->file_mode)) {
+		if (snd_seq_kernel_client_write_poll(dp->cseq, file, wait))
+			mask |= EPOLLOUT | EPOLLWRNORM;
+	}
+	return mask;
+}
diff --git a/sound/core/seq/oss/seq_oss_synth.c b/sound/core/seq/oss/seq_oss_synth.c
new file mode 100644
index 0000000000..e3394919da
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_synth.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * synth device handlers
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_synth.h"
+#include "seq_oss_midi.h"
+#include "../seq_lock.h"
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/nospec.h>
+
+/*
+ * constants
+ */
+#define SNDRV_SEQ_OSS_MAX_SYNTH_NAME	30
+#define MAX_SYSEX_BUFLEN		128
+
+
+/*
+ * definition of synth info records
+ */
+
+/* sysex buffer */
+struct seq_oss_synth_sysex {
+	int len;
+	int skip;
+	unsigned char buf[MAX_SYSEX_BUFLEN];
+};
+
+/* synth info */
+struct seq_oss_synth {
+	int seq_device;
+
+	/* for synth_info */
+	int synth_type;
+	int synth_subtype;
+	int nr_voices;
+
+	char name[SNDRV_SEQ_OSS_MAX_SYNTH_NAME];
+	struct snd_seq_oss_callback oper;
+
+	int opened;
+
+	void *private_data;
+	snd_use_lock_t use_lock;
+};
+
+
+/*
+ * device table
+ */
+static int max_synth_devs;
+static struct seq_oss_synth *synth_devs[SNDRV_SEQ_OSS_MAX_SYNTH_DEVS];
+static struct seq_oss_synth midi_synth_dev = {
+	.seq_device = -1,
+	.synth_type = SYNTH_TYPE_MIDI,
+	.synth_subtype = 0,
+	.nr_voices = 16,
+	.name = "MIDI",
+};
+
+static DEFINE_SPINLOCK(register_lock);
+
+/*
+ * prototypes
+ */
+static struct seq_oss_synth *get_synthdev(struct seq_oss_devinfo *dp, int dev);
+static void reset_channels(struct seq_oss_synthinfo *info);
+
+/*
+ * global initialization
+ */
+void __init
+snd_seq_oss_synth_init(void)
+{
+	snd_use_lock_init(&midi_synth_dev.use_lock);
+}
+
+/*
+ * registration of the synth device
+ */
+int
+snd_seq_oss_synth_probe(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	int i;
+	struct seq_oss_synth *rec;
+	struct snd_seq_oss_reg *reg = SNDRV_SEQ_DEVICE_ARGPTR(dev);
+	unsigned long flags;
+
+	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
+	if (!rec)
+		return -ENOMEM;
+	rec->seq_device = -1;
+	rec->synth_type = reg->type;
+	rec->synth_subtype = reg->subtype;
+	rec->nr_voices = reg->nvoices;
+	rec->oper = reg->oper;
+	rec->private_data = reg->private_data;
+	rec->opened = 0;
+	snd_use_lock_init(&rec->use_lock);
+
+	/* copy and truncate the name of synth device */
+	strscpy(rec->name, dev->name, sizeof(rec->name));
+
+	/* registration */
+	spin_lock_irqsave(&register_lock, flags);
+	for (i = 0; i < max_synth_devs; i++) {
+		if (synth_devs[i] == NULL)
+			break;
+	}
+	if (i >= max_synth_devs) {
+		if (max_synth_devs >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS) {
+			spin_unlock_irqrestore(&register_lock, flags);
+			pr_err("ALSA: seq_oss: no more synth slot\n");
+			kfree(rec);
+			return -ENOMEM;
+		}
+		max_synth_devs++;
+	}
+	rec->seq_device = i;
+	synth_devs[i] = rec;
+	spin_unlock_irqrestore(&register_lock, flags);
+	dev->driver_data = rec;
+#ifdef SNDRV_OSS_INFO_DEV_SYNTH
+	if (i < SNDRV_CARDS)
+		snd_oss_info_register(SNDRV_OSS_INFO_DEV_SYNTH, i, rec->name);
+#endif
+	return 0;
+}
+
+
+int
+snd_seq_oss_synth_remove(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	int index;
+	struct seq_oss_synth *rec = dev->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&register_lock, flags);
+	for (index = 0; index < max_synth_devs; index++) {
+		if (synth_devs[index] == rec)
+			break;
+	}
+	if (index >= max_synth_devs) {
+		spin_unlock_irqrestore(&register_lock, flags);
+		pr_err("ALSA: seq_oss: can't unregister synth\n");
+		return -EINVAL;
+	}
+	synth_devs[index] = NULL;
+	if (index == max_synth_devs - 1) {
+		for (index--; index >= 0; index--) {
+			if (synth_devs[index])
+				break;
+		}
+		max_synth_devs = index + 1;
+	}
+	spin_unlock_irqrestore(&register_lock, flags);
+#ifdef SNDRV_OSS_INFO_DEV_SYNTH
+	if (rec->seq_device < SNDRV_CARDS)
+		snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_SYNTH, rec->seq_device);
+#endif
+
+	snd_use_lock_sync(&rec->use_lock);
+	kfree(rec);
+
+	return 0;
+}
+
+
+/*
+ */
+static struct seq_oss_synth *
+get_sdev(int dev)
+{
+	struct seq_oss_synth *rec;
+	unsigned long flags;
+
+	spin_lock_irqsave(&register_lock, flags);
+	rec = synth_devs[dev];
+	if (rec)
+		snd_use_lock_use(&rec->use_lock);
+	spin_unlock_irqrestore(&register_lock, flags);
+	return rec;
+}
+
+
+/*
+ * set up synth tables
+ */
+
+void
+snd_seq_oss_synth_setup(struct seq_oss_devinfo *dp)
+{
+	int i;
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info;
+
+	dp->max_synthdev = max_synth_devs;
+	dp->synth_opened = 0;
+	memset(dp->synths, 0, sizeof(dp->synths));
+	for (i = 0; i < dp->max_synthdev; i++) {
+		rec = get_sdev(i);
+		if (rec == NULL)
+			continue;
+		if (rec->oper.open == NULL || rec->oper.close == NULL) {
+			snd_use_lock_free(&rec->use_lock);
+			continue;
+		}
+		info = &dp->synths[i];
+		info->arg.app_index = dp->port;
+		info->arg.file_mode = dp->file_mode;
+		info->arg.seq_mode = dp->seq_mode;
+		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
+			info->arg.event_passing = SNDRV_SEQ_OSS_PROCESS_EVENTS;
+		else
+			info->arg.event_passing = SNDRV_SEQ_OSS_PASS_EVENTS;
+		info->opened = 0;
+		if (!try_module_get(rec->oper.owner)) {
+			snd_use_lock_free(&rec->use_lock);
+			continue;
+		}
+		if (rec->oper.open(&info->arg, rec->private_data) < 0) {
+			module_put(rec->oper.owner);
+			snd_use_lock_free(&rec->use_lock);
+			continue;
+		}
+		info->nr_voices = rec->nr_voices;
+		if (info->nr_voices > 0) {
+			info->ch = kcalloc(info->nr_voices, sizeof(struct seq_oss_chinfo), GFP_KERNEL);
+			if (!info->ch) {
+				rec->oper.close(&info->arg);
+				module_put(rec->oper.owner);
+				snd_use_lock_free(&rec->use_lock);
+				continue;
+			}
+			reset_channels(info);
+		}
+		info->opened++;
+		rec->opened++;
+		dp->synth_opened++;
+		snd_use_lock_free(&rec->use_lock);
+	}
+}
+
+
+/*
+ * set up synth tables for MIDI emulation - /dev/music mode only
+ */
+
+void
+snd_seq_oss_synth_setup_midi(struct seq_oss_devinfo *dp)
+{
+	int i;
+
+	if (dp->max_synthdev >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS)
+		return;
+
+	for (i = 0; i < dp->max_mididev; i++) {
+		struct seq_oss_synthinfo *info;
+		info = &dp->synths[dp->max_synthdev];
+		if (snd_seq_oss_midi_open(dp, i, dp->file_mode) < 0)
+			continue;
+		info->arg.app_index = dp->port;
+		info->arg.file_mode = dp->file_mode;
+		info->arg.seq_mode = dp->seq_mode;
+		info->arg.private_data = info;
+		info->is_midi = 1;
+		info->midi_mapped = i;
+		info->arg.event_passing = SNDRV_SEQ_OSS_PASS_EVENTS;
+		snd_seq_oss_midi_get_addr(dp, i, &info->arg.addr);
+		info->opened = 1;
+		midi_synth_dev.opened++;
+		dp->max_synthdev++;
+		if (dp->max_synthdev >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS)
+			break;
+	}
+}
+
+
+/*
+ * clean up synth tables
+ */
+
+void
+snd_seq_oss_synth_cleanup(struct seq_oss_devinfo *dp)
+{
+	int i;
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info;
+
+	if (snd_BUG_ON(dp->max_synthdev > SNDRV_SEQ_OSS_MAX_SYNTH_DEVS))
+		return;
+	for (i = 0; i < dp->max_synthdev; i++) {
+		info = &dp->synths[i];
+		if (! info->opened)
+			continue;
+		if (info->is_midi) {
+			if (midi_synth_dev.opened > 0) {
+				snd_seq_oss_midi_close(dp, info->midi_mapped);
+				midi_synth_dev.opened--;
+			}
+		} else {
+			rec = get_sdev(i);
+			if (rec == NULL)
+				continue;
+			if (rec->opened > 0) {
+				rec->oper.close(&info->arg);
+				module_put(rec->oper.owner);
+				rec->opened = 0;
+			}
+			snd_use_lock_free(&rec->use_lock);
+		}
+		kfree(info->sysex);
+		info->sysex = NULL;
+		kfree(info->ch);
+		info->ch = NULL;
+	}
+	dp->synth_opened = 0;
+	dp->max_synthdev = 0;
+}
+
+static struct seq_oss_synthinfo *
+get_synthinfo_nospec(struct seq_oss_devinfo *dp, int dev)
+{
+	if (dev < 0 || dev >= dp->max_synthdev)
+		return NULL;
+	dev = array_index_nospec(dev, SNDRV_SEQ_OSS_MAX_SYNTH_DEVS);
+	return &dp->synths[dev];
+}
+
+/*
+ * return synth device information pointer
+ */
+static struct seq_oss_synth *
+get_synthdev(struct seq_oss_devinfo *dp, int dev)
+{
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev);
+
+	if (!info)
+		return NULL;
+	if (!info->opened)
+		return NULL;
+	if (info->is_midi) {
+		rec = &midi_synth_dev;
+		snd_use_lock_use(&rec->use_lock);
+	} else {
+		rec = get_sdev(dev);
+		if (!rec)
+			return NULL;
+	}
+	if (! rec->opened) {
+		snd_use_lock_free(&rec->use_lock);
+		return NULL;
+	}
+	return rec;
+}
+
+
+/*
+ * reset note and velocity on each channel.
+ */
+static void
+reset_channels(struct seq_oss_synthinfo *info)
+{
+	int i;
+	if (info->ch == NULL || ! info->nr_voices)
+		return;
+	for (i = 0; i < info->nr_voices; i++) {
+		info->ch[i].note = -1;
+		info->ch[i].vel = 0;
+	}
+}
+
+
+/*
+ * reset synth device:
+ * call reset callback.  if no callback is defined, send a heartbeat
+ * event to the corresponding port.
+ */
+void
+snd_seq_oss_synth_reset(struct seq_oss_devinfo *dp, int dev)
+{
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info;
+
+	info = get_synthinfo_nospec(dp, dev);
+	if (!info || !info->opened)
+		return;
+	if (info->sysex)
+		info->sysex->len = 0; /* reset sysex */
+	reset_channels(info);
+	if (info->is_midi) {
+		if (midi_synth_dev.opened <= 0)
+			return;
+		snd_seq_oss_midi_reset(dp, info->midi_mapped);
+		/* reopen the device */
+		snd_seq_oss_midi_close(dp, dev);
+		if (snd_seq_oss_midi_open(dp, info->midi_mapped,
+					  dp->file_mode) < 0) {
+			midi_synth_dev.opened--;
+			info->opened = 0;
+			kfree(info->sysex);
+			info->sysex = NULL;
+			kfree(info->ch);
+			info->ch = NULL;
+		}
+		return;
+	}
+
+	rec = get_sdev(dev);
+	if (rec == NULL)
+		return;
+	if (rec->oper.reset) {
+		rec->oper.reset(&info->arg);
+	} else {
+		struct snd_seq_event ev;
+		memset(&ev, 0, sizeof(ev));
+		snd_seq_oss_fill_addr(dp, &ev, info->arg.addr.client,
+				      info->arg.addr.port);
+		ev.type = SNDRV_SEQ_EVENT_RESET;
+		snd_seq_oss_dispatch(dp, &ev, 0, 0);
+	}
+	snd_use_lock_free(&rec->use_lock);
+}
+
+
+/*
+ * load a patch record:
+ * call load_patch callback function
+ */
+int
+snd_seq_oss_synth_load_patch(struct seq_oss_devinfo *dp, int dev, int fmt,
+			    const char __user *buf, int p, int c)
+{
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info;
+	int rc;
+
+	info = get_synthinfo_nospec(dp, dev);
+	if (!info)
+		return -ENXIO;
+
+	if (info->is_midi)
+		return 0;
+	rec = get_synthdev(dp, dev);
+	if (!rec)
+		return -ENXIO;
+
+	if (rec->oper.load_patch == NULL)
+		rc = -ENXIO;
+	else
+		rc = rec->oper.load_patch(&info->arg, fmt, buf, p, c);
+	snd_use_lock_free(&rec->use_lock);
+	return rc;
+}
+
+/*
+ * check if the device is valid synth device and return the synth info
+ */
+struct seq_oss_synthinfo *
+snd_seq_oss_synth_info(struct seq_oss_devinfo *dp, int dev)
+{
+	struct seq_oss_synth *rec;
+
+	rec = get_synthdev(dp, dev);
+	if (rec) {
+		snd_use_lock_free(&rec->use_lock);
+		return get_synthinfo_nospec(dp, dev);
+	}
+	return NULL;
+}
+
+
+/*
+ * receive OSS 6 byte sysex packet:
+ * the full sysex message will be sent if it reaches to the end of data
+ * (0xff).
+ */
+int
+snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf, struct snd_seq_event *ev)
+{
+	int i, send;
+	unsigned char *dest;
+	struct seq_oss_synth_sysex *sysex;
+	struct seq_oss_synthinfo *info;
+
+	info = snd_seq_oss_synth_info(dp, dev);
+	if (!info)
+		return -ENXIO;
+
+	sysex = info->sysex;
+	if (sysex == NULL) {
+		sysex = kzalloc(sizeof(*sysex), GFP_KERNEL);
+		if (sysex == NULL)
+			return -ENOMEM;
+		info->sysex = sysex;
+	}
+
+	send = 0;
+	dest = sysex->buf + sysex->len;
+	/* copy 6 byte packet to the buffer */
+	for (i = 0; i < 6; i++) {
+		if (buf[i] == 0xff) {
+			send = 1;
+			break;
+		}
+		dest[i] = buf[i];
+		sysex->len++;
+		if (sysex->len >= MAX_SYSEX_BUFLEN) {
+			sysex->len = 0;
+			sysex->skip = 1;
+			break;
+		}
+	}
+
+	if (sysex->len && send) {
+		if (sysex->skip) {
+			sysex->skip = 0;
+			sysex->len = 0;
+			return -EINVAL; /* skip */
+		}
+		/* copy the data to event record and send it */
+		ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
+		if (snd_seq_oss_synth_addr(dp, dev, ev))
+			return -EINVAL;
+		ev->data.ext.len = sysex->len;
+		ev->data.ext.ptr = sysex->buf;
+		sysex->len = 0;
+		return 0;
+	}
+
+	return -EINVAL; /* skip */
+}
+
+/*
+ * fill the event source/destination addresses
+ */
+int
+snd_seq_oss_synth_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_event *ev)
+{
+	struct seq_oss_synthinfo *info = snd_seq_oss_synth_info(dp, dev);
+
+	if (!info)
+		return -EINVAL;
+	snd_seq_oss_fill_addr(dp, ev, info->arg.addr.client,
+			      info->arg.addr.port);
+	return 0;
+}
+
+
+/*
+ * OSS compatible ioctl
+ */
+int
+snd_seq_oss_synth_ioctl(struct seq_oss_devinfo *dp, int dev, unsigned int cmd, unsigned long addr)
+{
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info;
+	int rc;
+
+	info = get_synthinfo_nospec(dp, dev);
+	if (!info || info->is_midi)
+		return -ENXIO;
+	rec = get_synthdev(dp, dev);
+	if (!rec)
+		return -ENXIO;
+	if (rec->oper.ioctl == NULL)
+		rc = -ENXIO;
+	else
+		rc = rec->oper.ioctl(&info->arg, cmd, addr);
+	snd_use_lock_free(&rec->use_lock);
+	return rc;
+}
+
+
+/*
+ * send OSS raw events - SEQ_PRIVATE and SEQ_VOLUME
+ */
+int
+snd_seq_oss_synth_raw_event(struct seq_oss_devinfo *dp, int dev, unsigned char *data, struct snd_seq_event *ev)
+{
+	struct seq_oss_synthinfo *info;
+
+	info = snd_seq_oss_synth_info(dp, dev);
+	if (!info || info->is_midi)
+		return -ENXIO;
+	ev->type = SNDRV_SEQ_EVENT_OSS;
+	memcpy(ev->data.raw8.d, data, 8);
+	return snd_seq_oss_synth_addr(dp, dev, ev);
+}
+
+
+/*
+ * create OSS compatible synth_info record
+ */
+int
+snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf)
+{
+	struct seq_oss_synth *rec;
+	struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev);
+
+	if (!info)
+		return -ENXIO;
+
+	if (info->is_midi) {
+		struct midi_info minf;
+		if (snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf))
+			return -ENXIO;
+		inf->synth_type = SYNTH_TYPE_MIDI;
+		inf->synth_subtype = 0;
+		inf->nr_voices = 16;
+		inf->device = dev;
+		strscpy(inf->name, minf.name, sizeof(inf->name));
+	} else {
+		rec = get_synthdev(dp, dev);
+		if (!rec)
+			return -ENXIO;
+		inf->synth_type = rec->synth_type;
+		inf->synth_subtype = rec->synth_subtype;
+		inf->nr_voices = rec->nr_voices;
+		inf->device = dev;
+		strscpy(inf->name, rec->name, sizeof(inf->name));
+		snd_use_lock_free(&rec->use_lock);
+	}
+	return 0;
+}
+
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ * proc interface
+ */
+void
+snd_seq_oss_synth_info_read(struct snd_info_buffer *buf)
+{
+	int i;
+	struct seq_oss_synth *rec;
+
+	snd_iprintf(buf, "\nNumber of synth devices: %d\n", max_synth_devs);
+	for (i = 0; i < max_synth_devs; i++) {
+		snd_iprintf(buf, "\nsynth %d: ", i);
+		rec = get_sdev(i);
+		if (rec == NULL) {
+			snd_iprintf(buf, "*empty*\n");
+			continue;
+		}
+		snd_iprintf(buf, "[%s]\n", rec->name);
+		snd_iprintf(buf, "  type 0x%x : subtype 0x%x : voices %d\n",
+			    rec->synth_type, rec->synth_subtype,
+			    rec->nr_voices);
+		snd_iprintf(buf, "  capabilities : ioctl %s / load_patch %s\n",
+			    enabled_str((long)rec->oper.ioctl),
+			    enabled_str((long)rec->oper.load_patch));
+		snd_use_lock_free(&rec->use_lock);
+	}
+}
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/seq/oss/seq_oss_synth.h b/sound/core/seq/oss/seq_oss_synth.h
new file mode 100644
index 0000000000..ffc40d8a7e
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_synth.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ *
+ * synth device information
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_SYNTH_H
+#define __SEQ_OSS_SYNTH_H
+
+#include "seq_oss_device.h"
+#include <sound/seq_oss_legacy.h>
+#include <sound/seq_device.h>
+
+void snd_seq_oss_synth_init(void);
+int snd_seq_oss_synth_probe(struct device *dev);
+int snd_seq_oss_synth_remove(struct device *dev);
+void snd_seq_oss_synth_setup(struct seq_oss_devinfo *dp);
+void snd_seq_oss_synth_setup_midi(struct seq_oss_devinfo *dp);
+void snd_seq_oss_synth_cleanup(struct seq_oss_devinfo *dp);
+
+void snd_seq_oss_synth_reset(struct seq_oss_devinfo *dp, int dev);
+int snd_seq_oss_synth_load_patch(struct seq_oss_devinfo *dp, int dev, int fmt,
+				 const char __user *buf, int p, int c);
+struct seq_oss_synthinfo *snd_seq_oss_synth_info(struct seq_oss_devinfo *dp,
+						 int dev);
+int snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf,
+			    struct snd_seq_event *ev);
+int snd_seq_oss_synth_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_event *ev);
+int snd_seq_oss_synth_ioctl(struct seq_oss_devinfo *dp, int dev, unsigned int cmd,
+			    unsigned long addr);
+int snd_seq_oss_synth_raw_event(struct seq_oss_devinfo *dp, int dev,
+				unsigned char *data, struct snd_seq_event *ev);
+
+int snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf);
+
+#endif
diff --git a/sound/core/seq/oss/seq_oss_timer.c b/sound/core/seq/oss/seq_oss_timer.c
new file mode 100644
index 0000000000..f9f57232a8
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_timer.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * Timer control routines
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_timer.h"
+#include "seq_oss_event.h"
+#include <sound/seq_oss_legacy.h>
+#include <linux/slab.h>
+
+/*
+ */
+#define MIN_OSS_TEMPO		8
+#define MAX_OSS_TEMPO		360
+#define MIN_OSS_TIMEBASE	1
+#define MAX_OSS_TIMEBASE	1000
+
+/*
+ */
+static void calc_alsa_tempo(struct seq_oss_timer *timer);
+static int send_timer_event(struct seq_oss_devinfo *dp, int type, int value);
+
+
+/*
+ * create and register a new timer.
+ * if queue is not started yet, start it.
+ */
+struct seq_oss_timer *
+snd_seq_oss_timer_new(struct seq_oss_devinfo *dp)
+{
+	struct seq_oss_timer *rec;
+
+	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
+	if (rec == NULL)
+		return NULL;
+
+	rec->dp = dp;
+	rec->cur_tick = 0;
+	rec->realtime = 0;
+	rec->running = 0;
+	rec->oss_tempo = 60;
+	rec->oss_timebase = 100;
+	calc_alsa_tempo(rec);
+
+	return rec;
+}
+
+
+/*
+ * delete timer.
+ * if no more timer exists, stop the queue.
+ */
+void
+snd_seq_oss_timer_delete(struct seq_oss_timer *rec)
+{
+	if (rec) {
+		snd_seq_oss_timer_stop(rec);
+		kfree(rec);
+	}
+}
+
+
+/*
+ * process one timing event
+ * return 1 : event proceseed -- skip this event
+ *        0 : not a timer event -- enqueue this event
+ */
+int
+snd_seq_oss_process_timer_event(struct seq_oss_timer *rec, union evrec *ev)
+{
+	abstime_t parm = ev->t.time;
+
+	if (ev->t.code == EV_TIMING) {
+		switch (ev->t.cmd) {
+		case TMR_WAIT_REL:
+			parm += rec->cur_tick;
+			rec->realtime = 0;
+			fallthrough;
+		case TMR_WAIT_ABS:
+			if (parm == 0) {
+				rec->realtime = 1;
+			} else if (parm >= rec->cur_tick) {
+				rec->realtime = 0;
+				rec->cur_tick = parm;
+			}
+			return 1;	/* skip this event */
+			
+		case TMR_START:
+			snd_seq_oss_timer_start(rec);
+			return 1;
+
+		}
+	} else if (ev->s.code == SEQ_WAIT) {
+		/* time = from 1 to 3 bytes */
+		parm = (ev->echo >> 8) & 0xffffff;
+		if (parm > rec->cur_tick) {
+			/* set next event time */
+			rec->cur_tick = parm;
+			rec->realtime = 0;
+		}
+		return 1;
+	}
+
+	return 0;
+}
+
+
+/*
+ * convert tempo units
+ */
+static void
+calc_alsa_tempo(struct seq_oss_timer *timer)
+{
+	timer->tempo = (60 * 1000000) / timer->oss_tempo;
+	timer->ppq = timer->oss_timebase;
+}
+
+
+/*
+ * dispatch a timer event
+ */
+static int
+send_timer_event(struct seq_oss_devinfo *dp, int type, int value)
+{
+	struct snd_seq_event ev;
+
+	memset(&ev, 0, sizeof(ev));
+	ev.type = type;
+	ev.source.client = dp->cseq;
+	ev.source.port = 0;
+	ev.dest.client = SNDRV_SEQ_CLIENT_SYSTEM;
+	ev.dest.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
+	ev.queue = dp->queue;
+	ev.data.queue.queue = dp->queue;
+	ev.data.queue.param.value = value;
+	return snd_seq_kernel_client_dispatch(dp->cseq, &ev, 1, 0);
+}
+
+/*
+ * set queue tempo and start queue
+ */
+int
+snd_seq_oss_timer_start(struct seq_oss_timer *timer)
+{
+	struct seq_oss_devinfo *dp = timer->dp;
+	struct snd_seq_queue_tempo tmprec;
+
+	if (timer->running)
+		snd_seq_oss_timer_stop(timer);
+
+	memset(&tmprec, 0, sizeof(tmprec));
+	tmprec.queue = dp->queue;
+	tmprec.ppq = timer->ppq;
+	tmprec.tempo = timer->tempo;
+	snd_seq_set_queue_tempo(dp->cseq, &tmprec);
+
+	send_timer_event(dp, SNDRV_SEQ_EVENT_START, 0);
+	timer->running = 1;
+	timer->cur_tick = 0;
+	return 0;
+}
+
+
+/*
+ * stop queue
+ */
+int
+snd_seq_oss_timer_stop(struct seq_oss_timer *timer)
+{
+	if (! timer->running)
+		return 0;
+	send_timer_event(timer->dp, SNDRV_SEQ_EVENT_STOP, 0);
+	timer->running = 0;
+	return 0;
+}
+
+
+/*
+ * continue queue
+ */
+int
+snd_seq_oss_timer_continue(struct seq_oss_timer *timer)
+{
+	if (timer->running)
+		return 0;
+	send_timer_event(timer->dp, SNDRV_SEQ_EVENT_CONTINUE, 0);
+	timer->running = 1;
+	return 0;
+}
+
+
+/*
+ * change queue tempo
+ */
+int
+snd_seq_oss_timer_tempo(struct seq_oss_timer *timer, int value)
+{
+	if (value < MIN_OSS_TEMPO)
+		value = MIN_OSS_TEMPO;
+	else if (value > MAX_OSS_TEMPO)
+		value = MAX_OSS_TEMPO;
+	timer->oss_tempo = value;
+	calc_alsa_tempo(timer);
+	if (timer->running)
+		send_timer_event(timer->dp, SNDRV_SEQ_EVENT_TEMPO, timer->tempo);
+	return 0;
+}
+
+
+/*
+ * ioctls
+ */
+int
+snd_seq_oss_timer_ioctl(struct seq_oss_timer *timer, unsigned int cmd, int __user *arg)
+{
+	int value;
+
+	if (cmd == SNDCTL_SEQ_CTRLRATE) {
+		/* if *arg == 0, just return the current rate */
+		if (get_user(value, arg))
+			return -EFAULT;
+		if (value)
+			return -EINVAL;
+		value = ((timer->oss_tempo * timer->oss_timebase) + 30) / 60;
+		return put_user(value, arg) ? -EFAULT : 0;
+	}
+
+	if (timer->dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
+		return 0;
+
+	switch (cmd) {
+	case SNDCTL_TMR_START:
+		return snd_seq_oss_timer_start(timer);
+	case SNDCTL_TMR_STOP:
+		return snd_seq_oss_timer_stop(timer);
+	case SNDCTL_TMR_CONTINUE:
+		return snd_seq_oss_timer_continue(timer);
+	case SNDCTL_TMR_TEMPO:
+		if (get_user(value, arg))
+			return -EFAULT;
+		return snd_seq_oss_timer_tempo(timer, value);
+	case SNDCTL_TMR_TIMEBASE:
+		if (get_user(value, arg))
+			return -EFAULT;
+		if (value < MIN_OSS_TIMEBASE)
+			value = MIN_OSS_TIMEBASE;
+		else if (value > MAX_OSS_TIMEBASE)
+			value = MAX_OSS_TIMEBASE;
+		timer->oss_timebase = value;
+		calc_alsa_tempo(timer);
+		return 0;
+
+	case SNDCTL_TMR_METRONOME:
+	case SNDCTL_TMR_SELECT:
+	case SNDCTL_TMR_SOURCE:
+		/* not supported */
+		return 0;
+	}
+	return 0;
+}
diff --git a/sound/core/seq/oss/seq_oss_timer.h b/sound/core/seq/oss/seq_oss_timer.h
new file mode 100644
index 0000000000..dee190b4ec
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_timer.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ * timer handling routines
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_TIMER_H
+#define __SEQ_OSS_TIMER_H
+
+#include "seq_oss_device.h"
+
+/*
+ * timer information definition
+ */
+struct seq_oss_timer {
+	struct seq_oss_devinfo *dp;
+	reltime_t cur_tick;
+	int realtime;
+	int running;
+	int tempo, ppq;	/* ALSA queue */
+	int oss_tempo, oss_timebase;
+};	
+
+
+struct seq_oss_timer *snd_seq_oss_timer_new(struct seq_oss_devinfo *dp);
+void snd_seq_oss_timer_delete(struct seq_oss_timer *dp);
+
+int snd_seq_oss_timer_start(struct seq_oss_timer *timer);
+int snd_seq_oss_timer_stop(struct seq_oss_timer *timer);
+int snd_seq_oss_timer_continue(struct seq_oss_timer *timer);
+int snd_seq_oss_timer_tempo(struct seq_oss_timer *timer, int value);
+#define snd_seq_oss_timer_reset  snd_seq_oss_timer_start
+
+int snd_seq_oss_timer_ioctl(struct seq_oss_timer *timer, unsigned int cmd, int __user *arg);
+
+/*
+ * get current processed time
+ */
+static inline abstime_t
+snd_seq_oss_timer_cur_tick(struct seq_oss_timer *timer)
+{
+	return timer->cur_tick;
+}
+
+#endif
diff --git a/sound/core/seq/oss/seq_oss_writeq.c b/sound/core/seq/oss/seq_oss_writeq.c
new file mode 100644
index 0000000000..3e3209ce53
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_writeq.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSS compatible sequencer driver
+ *
+ * seq_oss_writeq.c - write queue and sync
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include "seq_oss_writeq.h"
+#include "seq_oss_event.h"
+#include "seq_oss_timer.h"
+#include <sound/seq_oss_legacy.h>
+#include "../seq_lock.h"
+#include "../seq_clientmgr.h"
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+
+
+/*
+ * create a write queue record
+ */
+struct seq_oss_writeq *
+snd_seq_oss_writeq_new(struct seq_oss_devinfo *dp, int maxlen)
+{
+	struct seq_oss_writeq *q;
+	struct snd_seq_client_pool pool;
+
+	q = kzalloc(sizeof(*q), GFP_KERNEL);
+	if (!q)
+		return NULL;
+	q->dp = dp;
+	q->maxlen = maxlen;
+	spin_lock_init(&q->sync_lock);
+	q->sync_event_put = 0;
+	q->sync_time = 0;
+	init_waitqueue_head(&q->sync_sleep);
+
+	memset(&pool, 0, sizeof(pool));
+	pool.client = dp->cseq;
+	pool.output_pool = maxlen;
+	pool.output_room = maxlen / 2;
+
+	snd_seq_oss_control(dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
+
+	return q;
+}
+
+/*
+ * delete the write queue
+ */
+void
+snd_seq_oss_writeq_delete(struct seq_oss_writeq *q)
+{
+	if (q) {
+		snd_seq_oss_writeq_clear(q);	/* to be sure */
+		kfree(q);
+	}
+}
+
+
+/*
+ * reset the write queue
+ */
+void
+snd_seq_oss_writeq_clear(struct seq_oss_writeq *q)
+{
+	struct snd_seq_remove_events reset;
+
+	memset(&reset, 0, sizeof(reset));
+	reset.remove_mode = SNDRV_SEQ_REMOVE_OUTPUT; /* remove all */
+	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_REMOVE_EVENTS, &reset);
+
+	/* wake up sleepers if any */
+	snd_seq_oss_writeq_wakeup(q, 0);
+}
+
+/*
+ * wait until the write buffer has enough room
+ */
+int
+snd_seq_oss_writeq_sync(struct seq_oss_writeq *q)
+{
+	struct seq_oss_devinfo *dp = q->dp;
+	abstime_t time;
+
+	time = snd_seq_oss_timer_cur_tick(dp->timer);
+	if (q->sync_time >= time)
+		return 0; /* already finished */
+
+	if (! q->sync_event_put) {
+		struct snd_seq_event ev;
+		union evrec *rec;
+
+		/* put echoback event */
+		memset(&ev, 0, sizeof(ev));
+		ev.flags = 0;
+		ev.type = SNDRV_SEQ_EVENT_ECHO;
+		ev.time.tick = time;
+		/* echo back to itself */
+		snd_seq_oss_fill_addr(dp, &ev, dp->addr.client, dp->addr.port);
+		rec = (union evrec *)&ev.data;
+		rec->t.code = SEQ_SYNCTIMER;
+		rec->t.time = time;
+		q->sync_event_put = 1;
+		snd_seq_kernel_client_enqueue(dp->cseq, &ev, NULL, true);
+	}
+
+	wait_event_interruptible_timeout(q->sync_sleep, ! q->sync_event_put, HZ);
+	if (signal_pending(current))
+		/* interrupted - return 0 to finish sync */
+		q->sync_event_put = 0;
+	if (! q->sync_event_put || q->sync_time >= time)
+		return 0;
+	return 1;
+}
+
+/*
+ * wake up sync - echo event was catched
+ */
+void
+snd_seq_oss_writeq_wakeup(struct seq_oss_writeq *q, abstime_t time)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->sync_lock, flags);
+	q->sync_time = time;
+	q->sync_event_put = 0;
+	wake_up(&q->sync_sleep);
+	spin_unlock_irqrestore(&q->sync_lock, flags);
+}
+
+
+/*
+ * return the unused pool size
+ */
+int
+snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q)
+{
+	struct snd_seq_client_pool pool;
+	pool.client = q->dp->cseq;
+	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
+	return pool.output_free;
+}
+
+
+/*
+ * set output threshold size from ioctl
+ */
+void
+snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int val)
+{
+	struct snd_seq_client_pool pool;
+	pool.client = q->dp->cseq;
+	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
+	pool.output_room = val;
+	snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
+}
+
diff --git a/sound/core/seq/oss/seq_oss_writeq.h b/sound/core/seq/oss/seq_oss_writeq.h
new file mode 100644
index 0000000000..490d27a7b2
--- /dev/null
+++ b/sound/core/seq/oss/seq_oss_writeq.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OSS compatible sequencer driver
+ * write priority queue
+ *
+ * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
+ */
+
+#ifndef __SEQ_OSS_WRITEQ_H
+#define __SEQ_OSS_WRITEQ_H
+
+#include "seq_oss_device.h"
+
+
+struct seq_oss_writeq {
+	struct seq_oss_devinfo *dp;
+	int maxlen;
+	abstime_t sync_time;
+	int sync_event_put;
+	wait_queue_head_t sync_sleep;
+	spinlock_t sync_lock;
+};
+
+
+/*
+ * seq_oss_writeq.c
+ */
+struct seq_oss_writeq *snd_seq_oss_writeq_new(struct seq_oss_devinfo *dp, int maxlen);
+void snd_seq_oss_writeq_delete(struct seq_oss_writeq *q);
+void snd_seq_oss_writeq_clear(struct seq_oss_writeq *q);
+int snd_seq_oss_writeq_sync(struct seq_oss_writeq *q);
+void snd_seq_oss_writeq_wakeup(struct seq_oss_writeq *q, abstime_t time);
+int snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q);
+void snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int size);
+
+
+#endif
diff --git a/sound/core/seq/seq.c b/sound/core/seq/seq.c
new file mode 100644
index 0000000000..00f7342ee8
--- /dev/null
+++ b/sound/core/seq/seq.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  ALSA sequencer main module
+ *  Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+
+#include <sound/seq_kernel.h>
+#include "seq_clientmgr.h"
+#include "seq_memory.h"
+#include "seq_queue.h"
+#include "seq_lock.h"
+#include "seq_timer.h"
+#include "seq_system.h"
+#include "seq_info.h"
+#include <sound/minors.h>
+#include <sound/seq_device.h>
+
+#if defined(CONFIG_SND_SEQ_DUMMY_MODULE)
+int seq_client_load[15] = {[0] = SNDRV_SEQ_CLIENT_DUMMY, [1 ... 14] = -1};
+#else
+int seq_client_load[15] = {[0 ... 14] = -1};
+#endif
+int seq_default_timer_class = SNDRV_TIMER_CLASS_GLOBAL;
+int seq_default_timer_sclass = SNDRV_TIMER_SCLASS_NONE;
+int seq_default_timer_card = -1;
+int seq_default_timer_device =
+#ifdef CONFIG_SND_SEQ_HRTIMER_DEFAULT
+	SNDRV_TIMER_GLOBAL_HRTIMER
+#else
+	SNDRV_TIMER_GLOBAL_SYSTEM
+#endif
+	;
+int seq_default_timer_subdevice = 0;
+int seq_default_timer_resolution = 0;	/* Hz */
+
+MODULE_AUTHOR("Frank van de Pol <fvdpol@coil.demon.nl>, Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer.");
+MODULE_LICENSE("GPL");
+
+module_param_array(seq_client_load, int, NULL, 0444);
+MODULE_PARM_DESC(seq_client_load, "The numbers of global (system) clients to load through kmod.");
+module_param(seq_default_timer_class, int, 0644);
+MODULE_PARM_DESC(seq_default_timer_class, "The default timer class.");
+module_param(seq_default_timer_sclass, int, 0644);
+MODULE_PARM_DESC(seq_default_timer_sclass, "The default timer slave class.");
+module_param(seq_default_timer_card, int, 0644);
+MODULE_PARM_DESC(seq_default_timer_card, "The default timer card number.");
+module_param(seq_default_timer_device, int, 0644);
+MODULE_PARM_DESC(seq_default_timer_device, "The default timer device number.");
+module_param(seq_default_timer_subdevice, int, 0644);
+MODULE_PARM_DESC(seq_default_timer_subdevice, "The default timer subdevice number.");
+module_param(seq_default_timer_resolution, int, 0644);
+MODULE_PARM_DESC(seq_default_timer_resolution, "The default timer resolution in Hz.");
+
+MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_SEQUENCER);
+MODULE_ALIAS("devname:snd/seq");
+
+/*
+ *  INIT PART
+ */
+
+static int __init alsa_seq_init(void)
+{
+	int err;
+
+	err = client_init_data();
+	if (err < 0)
+		goto error;
+
+	/* register sequencer device */
+	err = snd_sequencer_device_init();
+	if (err < 0)
+		goto error;
+
+	/* register proc interface */
+	err = snd_seq_info_init();
+	if (err < 0)
+		goto error_device;
+
+	/* register our internal client */
+	err = snd_seq_system_client_init();
+	if (err < 0)
+		goto error_info;
+
+	snd_seq_autoload_init();
+	return 0;
+
+ error_info:
+	snd_seq_info_done();
+ error_device:
+	snd_sequencer_device_done();
+ error:
+	return err;
+}
+
+static void __exit alsa_seq_exit(void)
+{
+	/* unregister our internal client */
+	snd_seq_system_client_done();
+
+	/* unregister proc interface */
+	snd_seq_info_done();
+	
+	/* delete timing queues */
+	snd_seq_queues_delete();
+
+	/* unregister sequencer device */
+	snd_sequencer_device_done();
+
+	snd_seq_autoload_exit();
+}
+
+module_init(alsa_seq_init)
+module_exit(alsa_seq_exit)
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
new file mode 100644
index 0000000000..42a7051410
--- /dev/null
+++ b/sound/core/seq/seq_clientmgr.c
@@ -0,0 +1,2759 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  ALSA sequencer Client Manager
+ *  Copyright (c) 1998-2001 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *                             Jaroslav Kysela <perex@perex.cz>
+ *                             Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <linux/kmod.h>
+
+#include <sound/seq_kernel.h>
+#include <sound/ump.h>
+#include "seq_clientmgr.h"
+#include "seq_memory.h"
+#include "seq_queue.h"
+#include "seq_timer.h"
+#include "seq_info.h"
+#include "seq_system.h"
+#include "seq_ump_convert.h"
+#include <sound/seq_device.h>
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+#endif
+
+/* Client Manager
+
+ * this module handles the connections of userland and kernel clients
+ * 
+ */
+
+/*
+ * There are four ranges of client numbers (last two shared):
+ * 0..15: global clients
+ * 16..127: statically allocated client numbers for cards 0..27
+ * 128..191: dynamically allocated client numbers for cards 28..31
+ * 128..191: dynamically allocated client numbers for applications
+ */
+
+/* number of kernel non-card clients */
+#define SNDRV_SEQ_GLOBAL_CLIENTS	16
+/* clients per cards, for static clients */
+#define SNDRV_SEQ_CLIENTS_PER_CARD	4
+/* dynamically allocated client numbers (both kernel drivers and user space) */
+#define SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN	128
+
+#define SNDRV_SEQ_LFLG_INPUT	0x0001
+#define SNDRV_SEQ_LFLG_OUTPUT	0x0002
+#define SNDRV_SEQ_LFLG_OPEN	(SNDRV_SEQ_LFLG_INPUT|SNDRV_SEQ_LFLG_OUTPUT)
+
+static DEFINE_SPINLOCK(clients_lock);
+static DEFINE_MUTEX(register_mutex);
+
+/*
+ * client table
+ */
+static char clienttablock[SNDRV_SEQ_MAX_CLIENTS];
+static struct snd_seq_client *clienttab[SNDRV_SEQ_MAX_CLIENTS];
+static struct snd_seq_usage client_usage;
+
+/*
+ * prototypes
+ */
+static int bounce_error_event(struct snd_seq_client *client,
+			      struct snd_seq_event *event,
+			      int err, int atomic, int hop);
+static int snd_seq_deliver_single_event(struct snd_seq_client *client,
+					struct snd_seq_event *event,
+					int filter, int atomic, int hop);
+
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+static void free_ump_info(struct snd_seq_client *client);
+#endif
+
+/*
+ */
+static inline unsigned short snd_seq_file_flags(struct file *file)
+{
+        switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
+        case FMODE_WRITE:
+                return SNDRV_SEQ_LFLG_OUTPUT;
+        case FMODE_READ:
+                return SNDRV_SEQ_LFLG_INPUT;
+        default:
+                return SNDRV_SEQ_LFLG_OPEN;
+        }
+}
+
+static inline int snd_seq_write_pool_allocated(struct snd_seq_client *client)
+{
+	return snd_seq_total_cells(client->pool) > 0;
+}
+
+/* return pointer to client structure for specified id */
+static struct snd_seq_client *clientptr(int clientid)
+{
+	if (clientid < 0 || clientid >= SNDRV_SEQ_MAX_CLIENTS) {
+		pr_debug("ALSA: seq: oops. Trying to get pointer to client %d\n",
+			   clientid);
+		return NULL;
+	}
+	return clienttab[clientid];
+}
+
+struct snd_seq_client *snd_seq_client_use_ptr(int clientid)
+{
+	unsigned long flags;
+	struct snd_seq_client *client;
+
+	if (clientid < 0 || clientid >= SNDRV_SEQ_MAX_CLIENTS) {
+		pr_debug("ALSA: seq: oops. Trying to get pointer to client %d\n",
+			   clientid);
+		return NULL;
+	}
+	spin_lock_irqsave(&clients_lock, flags);
+	client = clientptr(clientid);
+	if (client)
+		goto __lock;
+	if (clienttablock[clientid]) {
+		spin_unlock_irqrestore(&clients_lock, flags);
+		return NULL;
+	}
+	spin_unlock_irqrestore(&clients_lock, flags);
+#ifdef CONFIG_MODULES
+	if (!in_interrupt()) {
+		static DECLARE_BITMAP(client_requested, SNDRV_SEQ_GLOBAL_CLIENTS);
+		static DECLARE_BITMAP(card_requested, SNDRV_CARDS);
+
+		if (clientid < SNDRV_SEQ_GLOBAL_CLIENTS) {
+			int idx;
+			
+			if (!test_and_set_bit(clientid, client_requested)) {
+				for (idx = 0; idx < 15; idx++) {
+					if (seq_client_load[idx] < 0)
+						break;
+					if (seq_client_load[idx] == clientid) {
+						request_module("snd-seq-client-%i",
+							       clientid);
+						break;
+					}
+				}
+			}
+		} else if (clientid < SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN) {
+			int card = (clientid - SNDRV_SEQ_GLOBAL_CLIENTS) /
+				SNDRV_SEQ_CLIENTS_PER_CARD;
+			if (card < snd_ecards_limit) {
+				if (!test_and_set_bit(card, card_requested))
+					snd_request_card(card);
+				snd_seq_device_load_drivers();
+			}
+		}
+		spin_lock_irqsave(&clients_lock, flags);
+		client = clientptr(clientid);
+		if (client)
+			goto __lock;
+		spin_unlock_irqrestore(&clients_lock, flags);
+	}
+#endif
+	return NULL;
+
+      __lock:
+	snd_use_lock_use(&client->use_lock);
+	spin_unlock_irqrestore(&clients_lock, flags);
+	return client;
+}
+
+/* Take refcount and perform ioctl_mutex lock on the given client;
+ * used only for OSS sequencer
+ * Unlock via snd_seq_client_ioctl_unlock() below
+ */
+bool snd_seq_client_ioctl_lock(int clientid)
+{
+	struct snd_seq_client *client;
+
+	client = snd_seq_client_use_ptr(clientid);
+	if (!client)
+		return false;
+	mutex_lock(&client->ioctl_mutex);
+	/* The client isn't unrefed here; see snd_seq_client_ioctl_unlock() */
+	return true;
+}
+EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_lock);
+
+/* Unlock and unref the given client; for OSS sequencer use only */
+void snd_seq_client_ioctl_unlock(int clientid)
+{
+	struct snd_seq_client *client;
+
+	client = snd_seq_client_use_ptr(clientid);
+	if (WARN_ON(!client))
+		return;
+	mutex_unlock(&client->ioctl_mutex);
+	/* The doubly unrefs below are intentional; the first one releases the
+	 * leftover from snd_seq_client_ioctl_lock() above, and the second one
+	 * is for releasing snd_seq_client_use_ptr() in this function
+	 */
+	snd_seq_client_unlock(client);
+	snd_seq_client_unlock(client);
+}
+EXPORT_SYMBOL_GPL(snd_seq_client_ioctl_unlock);
+
+static void usage_alloc(struct snd_seq_usage *res, int num)
+{
+	res->cur += num;
+	if (res->cur > res->peak)
+		res->peak = res->cur;
+}
+
+static void usage_free(struct snd_seq_usage *res, int num)
+{
+	res->cur -= num;
+}
+
+/* initialise data structures */
+int __init client_init_data(void)
+{
+	/* zap out the client table */
+	memset(&clienttablock, 0, sizeof(clienttablock));
+	memset(&clienttab, 0, sizeof(clienttab));
+	return 0;
+}
+
+
+static struct snd_seq_client *seq_create_client1(int client_index, int poolsize)
+{
+	int c;
+	struct snd_seq_client *client;
+
+	/* init client data */
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (client == NULL)
+		return NULL;
+	client->pool = snd_seq_pool_new(poolsize);
+	if (client->pool == NULL) {
+		kfree(client);
+		return NULL;
+	}
+	client->type = NO_CLIENT;
+	snd_use_lock_init(&client->use_lock);
+	rwlock_init(&client->ports_lock);
+	mutex_init(&client->ports_mutex);
+	INIT_LIST_HEAD(&client->ports_list_head);
+	mutex_init(&client->ioctl_mutex);
+	client->ump_endpoint_port = -1;
+
+	/* find free slot in the client table */
+	spin_lock_irq(&clients_lock);
+	if (client_index < 0) {
+		for (c = SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN;
+		     c < SNDRV_SEQ_MAX_CLIENTS;
+		     c++) {
+			if (clienttab[c] || clienttablock[c])
+				continue;
+			clienttab[client->number = c] = client;
+			spin_unlock_irq(&clients_lock);
+			return client;
+		}
+	} else {
+		if (clienttab[client_index] == NULL && !clienttablock[client_index]) {
+			clienttab[client->number = client_index] = client;
+			spin_unlock_irq(&clients_lock);
+			return client;
+		}
+	}
+	spin_unlock_irq(&clients_lock);
+	snd_seq_pool_delete(&client->pool);
+	kfree(client);
+	return NULL;	/* no free slot found or busy, return failure code */
+}
+
+
+static int seq_free_client1(struct snd_seq_client *client)
+{
+	if (!client)
+		return 0;
+	spin_lock_irq(&clients_lock);
+	clienttablock[client->number] = 1;
+	clienttab[client->number] = NULL;
+	spin_unlock_irq(&clients_lock);
+	snd_seq_delete_all_ports(client);
+	snd_seq_queue_client_leave(client->number);
+	snd_use_lock_sync(&client->use_lock);
+	if (client->pool)
+		snd_seq_pool_delete(&client->pool);
+	spin_lock_irq(&clients_lock);
+	clienttablock[client->number] = 0;
+	spin_unlock_irq(&clients_lock);
+	return 0;
+}
+
+
+static void seq_free_client(struct snd_seq_client * client)
+{
+	mutex_lock(&register_mutex);
+	switch (client->type) {
+	case NO_CLIENT:
+		pr_warn("ALSA: seq: Trying to free unused client %d\n",
+			client->number);
+		break;
+	case USER_CLIENT:
+	case KERNEL_CLIENT:
+		seq_free_client1(client);
+		usage_free(&client_usage, 1);
+		break;
+
+	default:
+		pr_err("ALSA: seq: Trying to free client %d with undefined type = %d\n",
+			   client->number, client->type);
+	}
+	mutex_unlock(&register_mutex);
+
+	snd_seq_system_client_ev_client_exit(client->number);
+}
+
+
+
+/* -------------------------------------------------------- */
+
+/* create a user client */
+static int snd_seq_open(struct inode *inode, struct file *file)
+{
+	int c, mode;			/* client id */
+	struct snd_seq_client *client;
+	struct snd_seq_user_client *user;
+	int err;
+
+	err = stream_open(inode, file);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&register_mutex);
+	client = seq_create_client1(-1, SNDRV_SEQ_DEFAULT_EVENTS);
+	if (!client) {
+		mutex_unlock(&register_mutex);
+		return -ENOMEM;	/* failure code */
+	}
+
+	mode = snd_seq_file_flags(file);
+	if (mode & SNDRV_SEQ_LFLG_INPUT)
+		client->accept_input = 1;
+	if (mode & SNDRV_SEQ_LFLG_OUTPUT)
+		client->accept_output = 1;
+
+	user = &client->data.user;
+	user->fifo = NULL;
+	user->fifo_pool_size = 0;
+
+	if (mode & SNDRV_SEQ_LFLG_INPUT) {
+		user->fifo_pool_size = SNDRV_SEQ_DEFAULT_CLIENT_EVENTS;
+		user->fifo = snd_seq_fifo_new(user->fifo_pool_size);
+		if (user->fifo == NULL) {
+			seq_free_client1(client);
+			kfree(client);
+			mutex_unlock(&register_mutex);
+			return -ENOMEM;
+		}
+	}
+
+	usage_alloc(&client_usage, 1);
+	client->type = USER_CLIENT;
+	mutex_unlock(&register_mutex);
+
+	c = client->number;
+	file->private_data = client;
+
+	/* fill client data */
+	user->file = file;
+	sprintf(client->name, "Client-%d", c);
+	client->data.user.owner = get_pid(task_pid(current));
+
+	/* make others aware this new client */
+	snd_seq_system_client_ev_client_start(c);
+
+	return 0;
+}
+
+/* delete a user client */
+static int snd_seq_release(struct inode *inode, struct file *file)
+{
+	struct snd_seq_client *client = file->private_data;
+
+	if (client) {
+		seq_free_client(client);
+		if (client->data.user.fifo)
+			snd_seq_fifo_delete(&client->data.user.fifo);
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+		free_ump_info(client);
+#endif
+		put_pid(client->data.user.owner);
+		kfree(client);
+	}
+
+	return 0;
+}
+
+static bool event_is_compatible(const struct snd_seq_client *client,
+				const struct snd_seq_event *ev)
+{
+	if (snd_seq_ev_is_ump(ev) && !client->midi_version)
+		return false;
+	if (snd_seq_ev_is_ump(ev) && snd_seq_ev_is_variable(ev))
+		return false;
+	return true;
+}
+
+/* handle client read() */
+/* possible error values:
+ *	-ENXIO	invalid client or file open mode
+ *	-ENOSPC	FIFO overflow (the flag is cleared after this error report)
+ *	-EINVAL	no enough user-space buffer to write the whole event
+ *	-EFAULT	seg. fault during copy to user space
+ */
+static ssize_t snd_seq_read(struct file *file, char __user *buf, size_t count,
+			    loff_t *offset)
+{
+	struct snd_seq_client *client = file->private_data;
+	struct snd_seq_fifo *fifo;
+	size_t aligned_size;
+	int err;
+	long result = 0;
+	struct snd_seq_event_cell *cell;
+
+	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT))
+		return -ENXIO;
+
+	if (!access_ok(buf, count))
+		return -EFAULT;
+
+	/* check client structures are in place */
+	if (snd_BUG_ON(!client))
+		return -ENXIO;
+
+	if (!client->accept_input)
+		return -ENXIO;
+	fifo = client->data.user.fifo;
+	if (!fifo)
+		return -ENXIO;
+
+	if (atomic_read(&fifo->overflow) > 0) {
+		/* buffer overflow is detected */
+		snd_seq_fifo_clear(fifo);
+		/* return error code */
+		return -ENOSPC;
+	}
+
+	cell = NULL;
+	err = 0;
+	snd_seq_fifo_lock(fifo);
+
+	if (IS_ENABLED(CONFIG_SND_SEQ_UMP) && client->midi_version > 0)
+		aligned_size = sizeof(struct snd_seq_ump_event);
+	else
+		aligned_size = sizeof(struct snd_seq_event);
+
+	/* while data available in queue */
+	while (count >= aligned_size) {
+		int nonblock;
+
+		nonblock = (file->f_flags & O_NONBLOCK) || result > 0;
+		err = snd_seq_fifo_cell_out(fifo, &cell, nonblock);
+		if (err < 0)
+			break;
+		if (!event_is_compatible(client, &cell->event)) {
+			snd_seq_cell_free(cell);
+			cell = NULL;
+			continue;
+		}
+		if (snd_seq_ev_is_variable(&cell->event)) {
+			struct snd_seq_ump_event tmpev;
+
+			memcpy(&tmpev, &cell->event, aligned_size);
+			tmpev.data.ext.len &= ~SNDRV_SEQ_EXT_MASK;
+			if (copy_to_user(buf, &tmpev, aligned_size)) {
+				err = -EFAULT;
+				break;
+			}
+			count -= aligned_size;
+			buf += aligned_size;
+			err = snd_seq_expand_var_event(&cell->event, count,
+						       (char __force *)buf, 0,
+						       aligned_size);
+			if (err < 0)
+				break;
+			result += err;
+			count -= err;
+			buf += err;
+		} else {
+			if (copy_to_user(buf, &cell->event, aligned_size)) {
+				err = -EFAULT;
+				break;
+			}
+			count -= aligned_size;
+			buf += aligned_size;
+		}
+		snd_seq_cell_free(cell);
+		cell = NULL; /* to be sure */
+		result += aligned_size;
+	}
+
+	if (err < 0) {
+		if (cell)
+			snd_seq_fifo_cell_putback(fifo, cell);
+		if (err == -EAGAIN && result > 0)
+			err = 0;
+	}
+	snd_seq_fifo_unlock(fifo);
+
+	return (err < 0) ? err : result;
+}
+
+
+/*
+ * check access permission to the port
+ */
+static int check_port_perm(struct snd_seq_client_port *port, unsigned int flags)
+{
+	if ((port->capability & flags) != flags)
+		return 0;
+	return flags;
+}
+
+/*
+ * check if the destination client is available, and return the pointer
+ * if filter is non-zero, client filter bitmap is tested.
+ */
+static struct snd_seq_client *get_event_dest_client(struct snd_seq_event *event,
+						    int filter)
+{
+	struct snd_seq_client *dest;
+
+	dest = snd_seq_client_use_ptr(event->dest.client);
+	if (dest == NULL)
+		return NULL;
+	if (! dest->accept_input)
+		goto __not_avail;
+	if ((dest->filter & SNDRV_SEQ_FILTER_USE_EVENT) &&
+	    ! test_bit(event->type, dest->event_filter))
+		goto __not_avail;
+	if (filter && !(dest->filter & filter))
+		goto __not_avail;
+
+	return dest; /* ok - accessible */
+__not_avail:
+	snd_seq_client_unlock(dest);
+	return NULL;
+}
+
+
+/*
+ * Return the error event.
+ *
+ * If the receiver client is a user client, the original event is
+ * encapsulated in SNDRV_SEQ_EVENT_BOUNCE as variable length event.  If
+ * the original event is also variable length, the external data is
+ * copied after the event record. 
+ * If the receiver client is a kernel client, the original event is
+ * quoted in SNDRV_SEQ_EVENT_KERNEL_ERROR, since this requires no extra
+ * kmalloc.
+ */
+static int bounce_error_event(struct snd_seq_client *client,
+			      struct snd_seq_event *event,
+			      int err, int atomic, int hop)
+{
+	struct snd_seq_event bounce_ev;
+	int result;
+
+	if (client == NULL ||
+	    ! (client->filter & SNDRV_SEQ_FILTER_BOUNCE) ||
+	    ! client->accept_input)
+		return 0; /* ignored */
+
+	/* set up quoted error */
+	memset(&bounce_ev, 0, sizeof(bounce_ev));
+	bounce_ev.type = SNDRV_SEQ_EVENT_KERNEL_ERROR;
+	bounce_ev.flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+	bounce_ev.queue = SNDRV_SEQ_QUEUE_DIRECT;
+	bounce_ev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
+	bounce_ev.source.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
+	bounce_ev.dest.client = client->number;
+	bounce_ev.dest.port = event->source.port;
+	bounce_ev.data.quote.origin = event->dest;
+	bounce_ev.data.quote.event = event;
+	bounce_ev.data.quote.value = -err; /* use positive value */
+	result = snd_seq_deliver_single_event(NULL, &bounce_ev, 0, atomic, hop + 1);
+	if (result < 0) {
+		client->event_lost++;
+		return result;
+	}
+
+	return result;
+}
+
+
+/*
+ * rewrite the time-stamp of the event record with the curren time
+ * of the given queue.
+ * return non-zero if updated.
+ */
+static int update_timestamp_of_queue(struct snd_seq_event *event,
+				     int queue, int real_time)
+{
+	struct snd_seq_queue *q;
+
+	q = queueptr(queue);
+	if (! q)
+		return 0;
+	event->queue = queue;
+	event->flags &= ~SNDRV_SEQ_TIME_STAMP_MASK;
+	if (real_time) {
+		event->time.time = snd_seq_timer_get_cur_time(q->timer, true);
+		event->flags |= SNDRV_SEQ_TIME_STAMP_REAL;
+	} else {
+		event->time.tick = snd_seq_timer_get_cur_tick(q->timer);
+		event->flags |= SNDRV_SEQ_TIME_STAMP_TICK;
+	}
+	queuefree(q);
+	return 1;
+}
+
+/* deliver a single event; called from below and UMP converter */
+int __snd_seq_deliver_single_event(struct snd_seq_client *dest,
+				   struct snd_seq_client_port *dest_port,
+				   struct snd_seq_event *event,
+				   int atomic, int hop)
+{
+	switch (dest->type) {
+	case USER_CLIENT:
+		if (!dest->data.user.fifo)
+			return 0;
+		return snd_seq_fifo_event_in(dest->data.user.fifo, event);
+	case KERNEL_CLIENT:
+		if (!dest_port->event_input)
+			return 0;
+		return dest_port->event_input(event,
+					      snd_seq_ev_is_direct(event),
+					      dest_port->private_data,
+					      atomic, hop);
+	}
+	return 0;
+}
+
+/*
+ * deliver an event to the specified destination.
+ * if filter is non-zero, client filter bitmap is tested.
+ *
+ *  RETURN VALUE: 0 : if succeeded
+ *		 <0 : error
+ */
+static int snd_seq_deliver_single_event(struct snd_seq_client *client,
+					struct snd_seq_event *event,
+					int filter, int atomic, int hop)
+{
+	struct snd_seq_client *dest = NULL;
+	struct snd_seq_client_port *dest_port = NULL;
+	int result = -ENOENT;
+	int direct;
+
+	direct = snd_seq_ev_is_direct(event);
+
+	dest = get_event_dest_client(event, filter);
+	if (dest == NULL)
+		goto __skip;
+	dest_port = snd_seq_port_use_ptr(dest, event->dest.port);
+	if (dest_port == NULL)
+		goto __skip;
+
+	/* check permission */
+	if (! check_port_perm(dest_port, SNDRV_SEQ_PORT_CAP_WRITE)) {
+		result = -EPERM;
+		goto __skip;
+	}
+		
+	if (dest_port->timestamping)
+		update_timestamp_of_queue(event, dest_port->time_queue,
+					  dest_port->time_real);
+
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+	if (!(dest->filter & SNDRV_SEQ_FILTER_NO_CONVERT)) {
+		if (snd_seq_ev_is_ump(event)) {
+			result = snd_seq_deliver_from_ump(client, dest, dest_port,
+							  event, atomic, hop);
+			goto __skip;
+		} else if (snd_seq_client_is_ump(dest)) {
+			result = snd_seq_deliver_to_ump(client, dest, dest_port,
+							event, atomic, hop);
+			goto __skip;
+		}
+	}
+#endif /* CONFIG_SND_SEQ_UMP */
+
+	result = __snd_seq_deliver_single_event(dest, dest_port, event,
+						atomic, hop);
+
+  __skip:
+	if (dest_port)
+		snd_seq_port_unlock(dest_port);
+	if (dest)
+		snd_seq_client_unlock(dest);
+
+	if (result < 0 && !direct) {
+		result = bounce_error_event(client, event, result, atomic, hop);
+	}
+	return result;
+}
+
+
+/*
+ * send the event to all subscribers:
+ */
+static int __deliver_to_subscribers(struct snd_seq_client *client,
+				    struct snd_seq_event *event,
+				    struct snd_seq_client_port *src_port,
+				    int atomic, int hop)
+{
+	struct snd_seq_subscribers *subs;
+	int err, result = 0, num_ev = 0;
+	union __snd_seq_event event_saved;
+	size_t saved_size;
+	struct snd_seq_port_subs_info *grp;
+
+	/* save original event record */
+	saved_size = snd_seq_event_packet_size(event);
+	memcpy(&event_saved, event, saved_size);
+	grp = &src_port->c_src;
+	
+	/* lock list */
+	if (atomic)
+		read_lock(&grp->list_lock);
+	else
+		down_read_nested(&grp->list_mutex, hop);
+	list_for_each_entry(subs, &grp->list_head, src_list) {
+		/* both ports ready? */
+		if (atomic_read(&subs->ref_count) != 2)
+			continue;
+		event->dest = subs->info.dest;
+		if (subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
+			/* convert time according to flag with subscription */
+			update_timestamp_of_queue(event, subs->info.queue,
+						  subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL);
+		err = snd_seq_deliver_single_event(client, event,
+						   0, atomic, hop);
+		if (err < 0) {
+			/* save first error that occurs and continue */
+			if (!result)
+				result = err;
+			continue;
+		}
+		num_ev++;
+		/* restore original event record */
+		memcpy(event, &event_saved, saved_size);
+	}
+	if (atomic)
+		read_unlock(&grp->list_lock);
+	else
+		up_read(&grp->list_mutex);
+	memcpy(event, &event_saved, saved_size);
+	return (result < 0) ? result : num_ev;
+}
+
+static int deliver_to_subscribers(struct snd_seq_client *client,
+				  struct snd_seq_event *event,
+				  int atomic, int hop)
+{
+	struct snd_seq_client_port *src_port;
+	int ret = 0, ret2;
+
+	src_port = snd_seq_port_use_ptr(client, event->source.port);
+	if (src_port) {
+		ret = __deliver_to_subscribers(client, event, src_port, atomic, hop);
+		snd_seq_port_unlock(src_port);
+	}
+
+	if (client->ump_endpoint_port < 0 ||
+	    event->source.port == client->ump_endpoint_port)
+		return ret;
+
+	src_port = snd_seq_port_use_ptr(client, client->ump_endpoint_port);
+	if (!src_port)
+		return ret;
+	ret2 = __deliver_to_subscribers(client, event, src_port, atomic, hop);
+	snd_seq_port_unlock(src_port);
+	return ret2 < 0 ? ret2 : ret;
+}
+
+/* deliver an event to the destination port(s).
+ * if the event is to subscribers or broadcast, the event is dispatched
+ * to multiple targets.
+ *
+ * RETURN VALUE: n > 0  : the number of delivered events.
+ *               n == 0 : the event was not passed to any client.
+ *               n < 0  : error - event was not processed.
+ */
+static int snd_seq_deliver_event(struct snd_seq_client *client, struct snd_seq_event *event,
+				 int atomic, int hop)
+{
+	int result;
+
+	hop++;
+	if (hop >= SNDRV_SEQ_MAX_HOPS) {
+		pr_debug("ALSA: seq: too long delivery path (%d:%d->%d:%d)\n",
+			   event->source.client, event->source.port,
+			   event->dest.client, event->dest.port);
+		return -EMLINK;
+	}
+
+	if (snd_seq_ev_is_variable(event) &&
+	    snd_BUG_ON(atomic && (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR)))
+		return -EINVAL;
+
+	if (event->queue == SNDRV_SEQ_ADDRESS_SUBSCRIBERS ||
+	    event->dest.client == SNDRV_SEQ_ADDRESS_SUBSCRIBERS)
+		result = deliver_to_subscribers(client, event, atomic, hop);
+	else
+		result = snd_seq_deliver_single_event(client, event, 0, atomic, hop);
+
+	return result;
+}
+
+/*
+ * dispatch an event cell:
+ * This function is called only from queue check routines in timer
+ * interrupts or after enqueued.
+ * The event cell shall be released or re-queued in this function.
+ *
+ * RETURN VALUE: n > 0  : the number of delivered events.
+ *		 n == 0 : the event was not passed to any client.
+ *		 n < 0  : error - event was not processed.
+ */
+int snd_seq_dispatch_event(struct snd_seq_event_cell *cell, int atomic, int hop)
+{
+	struct snd_seq_client *client;
+	int result;
+
+	if (snd_BUG_ON(!cell))
+		return -EINVAL;
+
+	client = snd_seq_client_use_ptr(cell->event.source.client);
+	if (client == NULL) {
+		snd_seq_cell_free(cell); /* release this cell */
+		return -EINVAL;
+	}
+
+	if (!snd_seq_ev_is_ump(&cell->event) &&
+	    cell->event.type == SNDRV_SEQ_EVENT_NOTE) {
+		/* NOTE event:
+		 * the event cell is re-used as a NOTE-OFF event and
+		 * enqueued again.
+		 */
+		struct snd_seq_event tmpev, *ev;
+
+		/* reserve this event to enqueue note-off later */
+		tmpev = cell->event;
+		tmpev.type = SNDRV_SEQ_EVENT_NOTEON;
+		result = snd_seq_deliver_event(client, &tmpev, atomic, hop);
+
+		/*
+		 * This was originally a note event.  We now re-use the
+		 * cell for the note-off event.
+		 */
+
+		ev = &cell->event;
+		ev->type = SNDRV_SEQ_EVENT_NOTEOFF;
+		ev->flags |= SNDRV_SEQ_PRIORITY_HIGH;
+
+		/* add the duration time */
+		switch (ev->flags & SNDRV_SEQ_TIME_STAMP_MASK) {
+		case SNDRV_SEQ_TIME_STAMP_TICK:
+			cell->event.time.tick += ev->data.note.duration;
+			break;
+		case SNDRV_SEQ_TIME_STAMP_REAL:
+			/* unit for duration is ms */
+			ev->time.time.tv_nsec += 1000000 * (ev->data.note.duration % 1000);
+			ev->time.time.tv_sec += ev->data.note.duration / 1000 +
+						ev->time.time.tv_nsec / 1000000000;
+			ev->time.time.tv_nsec %= 1000000000;
+			break;
+		}
+		ev->data.note.velocity = ev->data.note.off_velocity;
+
+		/* Now queue this cell as the note off event */
+		if (snd_seq_enqueue_event(cell, atomic, hop) < 0)
+			snd_seq_cell_free(cell); /* release this cell */
+
+	} else {
+		/* Normal events:
+		 * event cell is freed after processing the event
+		 */
+
+		result = snd_seq_deliver_event(client, &cell->event, atomic, hop);
+		snd_seq_cell_free(cell);
+	}
+
+	snd_seq_client_unlock(client);
+	return result;
+}
+
+
+/* Allocate a cell from client pool and enqueue it to queue:
+ * if pool is empty and blocking is TRUE, sleep until a new cell is
+ * available.
+ */
+static int snd_seq_client_enqueue_event(struct snd_seq_client *client,
+					struct snd_seq_event *event,
+					struct file *file, int blocking,
+					int atomic, int hop,
+					struct mutex *mutexp)
+{
+	struct snd_seq_event_cell *cell;
+	int err;
+
+	/* special queue values - force direct passing */
+	if (event->queue == SNDRV_SEQ_ADDRESS_SUBSCRIBERS) {
+		event->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+		event->queue = SNDRV_SEQ_QUEUE_DIRECT;
+	} else if (event->dest.client == SNDRV_SEQ_ADDRESS_SUBSCRIBERS) {
+		/* check presence of source port */
+		struct snd_seq_client_port *src_port = snd_seq_port_use_ptr(client, event->source.port);
+		if (src_port == NULL)
+			return -EINVAL;
+		snd_seq_port_unlock(src_port);
+	}
+
+	/* direct event processing without enqueued */
+	if (snd_seq_ev_is_direct(event)) {
+		if (!snd_seq_ev_is_ump(event) &&
+		    event->type == SNDRV_SEQ_EVENT_NOTE)
+			return -EINVAL; /* this event must be enqueued! */
+		return snd_seq_deliver_event(client, event, atomic, hop);
+	}
+
+	/* Not direct, normal queuing */
+	if (snd_seq_queue_is_used(event->queue, client->number) <= 0)
+		return -EINVAL;  /* invalid queue */
+	if (! snd_seq_write_pool_allocated(client))
+		return -ENXIO; /* queue is not allocated */
+
+	/* allocate an event cell */
+	err = snd_seq_event_dup(client->pool, event, &cell, !blocking || atomic,
+				file, mutexp);
+	if (err < 0)
+		return err;
+
+	/* we got a cell. enqueue it. */
+	err = snd_seq_enqueue_event(cell, atomic, hop);
+	if (err < 0) {
+		snd_seq_cell_free(cell);
+		return err;
+	}
+
+	return 0;
+}
+
+
+/*
+ * check validity of event type and data length.
+ * return non-zero if invalid.
+ */
+static int check_event_type_and_length(struct snd_seq_event *ev)
+{
+	switch (snd_seq_ev_length_type(ev)) {
+	case SNDRV_SEQ_EVENT_LENGTH_FIXED:
+		if (snd_seq_ev_is_variable_type(ev))
+			return -EINVAL;
+		break;
+	case SNDRV_SEQ_EVENT_LENGTH_VARIABLE:
+		if (! snd_seq_ev_is_variable_type(ev) ||
+		    (ev->data.ext.len & ~SNDRV_SEQ_EXT_MASK) >= SNDRV_SEQ_MAX_EVENT_LEN)
+			return -EINVAL;
+		break;
+	case SNDRV_SEQ_EVENT_LENGTH_VARUSR:
+		if (! snd_seq_ev_is_direct(ev))
+			return -EINVAL;
+		break;
+	}
+	return 0;
+}
+
+
+/* handle write() */
+/* possible error values:
+ *	-ENXIO	invalid client or file open mode
+ *	-ENOMEM	malloc failed
+ *	-EFAULT	seg. fault during copy from user space
+ *	-EINVAL	invalid event
+ *	-EAGAIN	no space in output pool
+ *	-EINTR	interrupts while sleep
+ *	-EMLINK	too many hops
+ *	others	depends on return value from driver callback
+ */
+static ssize_t snd_seq_write(struct file *file, const char __user *buf,
+			     size_t count, loff_t *offset)
+{
+	struct snd_seq_client *client = file->private_data;
+	int written = 0, len;
+	int err, handled;
+	union __snd_seq_event __event;
+	struct snd_seq_event *ev = &__event.legacy;
+
+	if (!(snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT))
+		return -ENXIO;
+
+	/* check client structures are in place */
+	if (snd_BUG_ON(!client))
+		return -ENXIO;
+		
+	if (!client->accept_output || client->pool == NULL)
+		return -ENXIO;
+
+ repeat:
+	handled = 0;
+	/* allocate the pool now if the pool is not allocated yet */ 
+	mutex_lock(&client->ioctl_mutex);
+	if (client->pool->size > 0 && !snd_seq_write_pool_allocated(client)) {
+		err = snd_seq_pool_init(client->pool);
+		if (err < 0)
+			goto out;
+	}
+
+	/* only process whole events */
+	err = -EINVAL;
+	while (count >= sizeof(struct snd_seq_event)) {
+		/* Read in the event header from the user */
+		len = sizeof(struct snd_seq_event);
+		if (copy_from_user(ev, buf, len)) {
+			err = -EFAULT;
+			break;
+		}
+		/* read in the rest bytes for UMP events */
+		if (snd_seq_ev_is_ump(ev)) {
+			if (count < sizeof(struct snd_seq_ump_event))
+				break;
+			if (copy_from_user((char *)ev + len, buf + len,
+					   sizeof(struct snd_seq_ump_event) - len)) {
+				err = -EFAULT;
+				break;
+			}
+			len = sizeof(struct snd_seq_ump_event);
+		}
+
+		ev->source.client = client->number;	/* fill in client number */
+		/* Check for extension data length */
+		if (check_event_type_and_length(ev)) {
+			err = -EINVAL;
+			break;
+		}
+
+		if (!event_is_compatible(client, ev)) {
+			err = -EINVAL;
+			break;
+		}
+
+		/* check for special events */
+		if (!snd_seq_ev_is_ump(ev)) {
+			if (ev->type == SNDRV_SEQ_EVENT_NONE)
+				goto __skip_event;
+			else if (snd_seq_ev_is_reserved(ev)) {
+				err = -EINVAL;
+				break;
+			}
+		}
+
+		if (snd_seq_ev_is_variable(ev)) {
+			int extlen = ev->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
+			if ((size_t)(extlen + len) > count) {
+				/* back out, will get an error this time or next */
+				err = -EINVAL;
+				break;
+			}
+			/* set user space pointer */
+			ev->data.ext.len = extlen | SNDRV_SEQ_EXT_USRPTR;
+			ev->data.ext.ptr = (char __force *)buf + len;
+			len += extlen; /* increment data length */
+		} else {
+#ifdef CONFIG_COMPAT
+			if (client->convert32 && snd_seq_ev_is_varusr(ev))
+				ev->data.ext.ptr =
+					(void __force *)compat_ptr(ev->data.raw32.d[1]);
+#endif
+		}
+
+		/* ok, enqueue it */
+		err = snd_seq_client_enqueue_event(client, ev, file,
+						   !(file->f_flags & O_NONBLOCK),
+						   0, 0, &client->ioctl_mutex);
+		if (err < 0)
+			break;
+		handled++;
+
+	__skip_event:
+		/* Update pointers and counts */
+		count -= len;
+		buf += len;
+		written += len;
+
+		/* let's have a coffee break if too many events are queued */
+		if (++handled >= 200) {
+			mutex_unlock(&client->ioctl_mutex);
+			goto repeat;
+		}
+	}
+
+ out:
+	mutex_unlock(&client->ioctl_mutex);
+	return written ? written : err;
+}
+
+
+/*
+ * handle polling
+ */
+static __poll_t snd_seq_poll(struct file *file, poll_table * wait)
+{
+	struct snd_seq_client *client = file->private_data;
+	__poll_t mask = 0;
+
+	/* check client structures are in place */
+	if (snd_BUG_ON(!client))
+		return EPOLLERR;
+
+	if ((snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_INPUT) &&
+	    client->data.user.fifo) {
+
+		/* check if data is available in the outqueue */
+		if (snd_seq_fifo_poll_wait(client->data.user.fifo, file, wait))
+			mask |= EPOLLIN | EPOLLRDNORM;
+	}
+
+	if (snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT) {
+
+		/* check if data is available in the pool */
+		if (!snd_seq_write_pool_allocated(client) ||
+		    snd_seq_pool_poll_wait(client->pool, file, wait))
+			mask |= EPOLLOUT | EPOLLWRNORM;
+	}
+
+	return mask;
+}
+
+
+/*-----------------------------------------------------*/
+
+static int snd_seq_ioctl_pversion(struct snd_seq_client *client, void *arg)
+{
+	int *pversion = arg;
+
+	*pversion = SNDRV_SEQ_VERSION;
+	return 0;
+}
+
+static int snd_seq_ioctl_user_pversion(struct snd_seq_client *client, void *arg)
+{
+	client->user_pversion = *(unsigned int *)arg;
+	return 0;
+}
+
+static int snd_seq_ioctl_client_id(struct snd_seq_client *client, void *arg)
+{
+	int *client_id = arg;
+
+	*client_id = client->number;
+	return 0;
+}
+
+/* SYSTEM_INFO ioctl() */
+static int snd_seq_ioctl_system_info(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_system_info *info = arg;
+
+	memset(info, 0, sizeof(*info));
+	/* fill the info fields */
+	info->queues = SNDRV_SEQ_MAX_QUEUES;
+	info->clients = SNDRV_SEQ_MAX_CLIENTS;
+	info->ports = SNDRV_SEQ_MAX_PORTS;
+	info->channels = 256;	/* fixed limit */
+	info->cur_clients = client_usage.cur;
+	info->cur_queues = snd_seq_queue_get_cur_queues();
+
+	return 0;
+}
+
+
+/* RUNNING_MODE ioctl() */
+static int snd_seq_ioctl_running_mode(struct snd_seq_client *client, void  *arg)
+{
+	struct snd_seq_running_info *info = arg;
+	struct snd_seq_client *cptr;
+	int err = 0;
+
+	/* requested client number */
+	cptr = snd_seq_client_use_ptr(info->client);
+	if (cptr == NULL)
+		return -ENOENT;		/* don't change !!! */
+
+#ifdef SNDRV_BIG_ENDIAN
+	if (!info->big_endian) {
+		err = -EINVAL;
+		goto __err;
+	}
+#else
+	if (info->big_endian) {
+		err = -EINVAL;
+		goto __err;
+	}
+
+#endif
+	if (info->cpu_mode > sizeof(long)) {
+		err = -EINVAL;
+		goto __err;
+	}
+	cptr->convert32 = (info->cpu_mode < sizeof(long));
+ __err:
+	snd_seq_client_unlock(cptr);
+	return err;
+}
+
+/* CLIENT_INFO ioctl() */
+static void get_client_info(struct snd_seq_client *cptr,
+			    struct snd_seq_client_info *info)
+{
+	info->client = cptr->number;
+
+	/* fill the info fields */
+	info->type = cptr->type;
+	strcpy(info->name, cptr->name);
+	info->filter = cptr->filter;
+	info->event_lost = cptr->event_lost;
+	memcpy(info->event_filter, cptr->event_filter, 32);
+	info->group_filter = cptr->group_filter;
+	info->num_ports = cptr->num_ports;
+
+	if (cptr->type == USER_CLIENT)
+		info->pid = pid_vnr(cptr->data.user.owner);
+	else
+		info->pid = -1;
+
+	if (cptr->type == KERNEL_CLIENT)
+		info->card = cptr->data.kernel.card ? cptr->data.kernel.card->number : -1;
+	else
+		info->card = -1;
+
+	info->midi_version = cptr->midi_version;
+	memset(info->reserved, 0, sizeof(info->reserved));
+}
+
+static int snd_seq_ioctl_get_client_info(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_client_info *client_info = arg;
+	struct snd_seq_client *cptr;
+
+	/* requested client number */
+	cptr = snd_seq_client_use_ptr(client_info->client);
+	if (cptr == NULL)
+		return -ENOENT;		/* don't change !!! */
+
+	get_client_info(cptr, client_info);
+	snd_seq_client_unlock(cptr);
+
+	return 0;
+}
+
+
+/* CLIENT_INFO ioctl() */
+static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_client_info *client_info = arg;
+
+	/* it is not allowed to set the info fields for an another client */
+	if (client->number != client_info->client)
+		return -EPERM;
+	/* also client type must be set now */
+	if (client->type != client_info->type)
+		return -EINVAL;
+
+	/* check validity of midi_version field */
+	if (client->user_pversion >= SNDRV_PROTOCOL_VERSION(1, 0, 3) &&
+	    client_info->midi_version > SNDRV_SEQ_CLIENT_UMP_MIDI_2_0)
+		return -EINVAL;
+
+	/* fill the info fields */
+	if (client_info->name[0])
+		strscpy(client->name, client_info->name, sizeof(client->name));
+
+	client->filter = client_info->filter;
+	client->event_lost = client_info->event_lost;
+	if (client->user_pversion >= SNDRV_PROTOCOL_VERSION(1, 0, 3))
+		client->midi_version = client_info->midi_version;
+	memcpy(client->event_filter, client_info->event_filter, 32);
+	client->group_filter = client_info->group_filter;
+	return 0;
+}
+
+
+/* 
+ * CREATE PORT ioctl() 
+ */
+static int snd_seq_ioctl_create_port(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_port_info *info = arg;
+	struct snd_seq_client_port *port;
+	struct snd_seq_port_callback *callback;
+	int port_idx, err;
+
+	/* it is not allowed to create the port for an another client */
+	if (info->addr.client != client->number)
+		return -EPERM;
+	if (client->type == USER_CLIENT && info->kernel)
+		return -EINVAL;
+	if ((info->capability & SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT) &&
+	    client->ump_endpoint_port >= 0)
+		return -EBUSY;
+
+	if (info->flags & SNDRV_SEQ_PORT_FLG_GIVEN_PORT)
+		port_idx = info->addr.port;
+	else
+		port_idx = -1;
+	if (port_idx >= SNDRV_SEQ_ADDRESS_UNKNOWN)
+		return -EINVAL;
+	err = snd_seq_create_port(client, port_idx, &port);
+	if (err < 0)
+		return err;
+
+	if (client->type == KERNEL_CLIENT) {
+		callback = info->kernel;
+		if (callback) {
+			if (callback->owner)
+				port->owner = callback->owner;
+			port->private_data = callback->private_data;
+			port->private_free = callback->private_free;
+			port->event_input = callback->event_input;
+			port->c_src.open = callback->subscribe;
+			port->c_src.close = callback->unsubscribe;
+			port->c_dest.open = callback->use;
+			port->c_dest.close = callback->unuse;
+		}
+	}
+
+	info->addr = port->addr;
+
+	snd_seq_set_port_info(port, info);
+	if (info->capability & SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT)
+		client->ump_endpoint_port = port->addr.port;
+	snd_seq_system_client_ev_port_start(port->addr.client, port->addr.port);
+	snd_seq_port_unlock(port);
+
+	return 0;
+}
+
+/* 
+ * DELETE PORT ioctl() 
+ */
+static int snd_seq_ioctl_delete_port(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_port_info *info = arg;
+	int err;
+
+	/* it is not allowed to remove the port for an another client */
+	if (info->addr.client != client->number)
+		return -EPERM;
+
+	err = snd_seq_delete_port(client, info->addr.port);
+	if (err >= 0) {
+		if (client->ump_endpoint_port == info->addr.port)
+			client->ump_endpoint_port = -1;
+		snd_seq_system_client_ev_port_exit(client->number, info->addr.port);
+	}
+	return err;
+}
+
+
+/* 
+ * GET_PORT_INFO ioctl() (on any client) 
+ */
+static int snd_seq_ioctl_get_port_info(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_port_info *info = arg;
+	struct snd_seq_client *cptr;
+	struct snd_seq_client_port *port;
+
+	cptr = snd_seq_client_use_ptr(info->addr.client);
+	if (cptr == NULL)
+		return -ENXIO;
+
+	port = snd_seq_port_use_ptr(cptr, info->addr.port);
+	if (port == NULL) {
+		snd_seq_client_unlock(cptr);
+		return -ENOENT;			/* don't change */
+	}
+
+	/* get port info */
+	snd_seq_get_port_info(port, info);
+	snd_seq_port_unlock(port);
+	snd_seq_client_unlock(cptr);
+
+	return 0;
+}
+
+
+/* 
+ * SET_PORT_INFO ioctl() (only ports on this/own client) 
+ */
+static int snd_seq_ioctl_set_port_info(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_port_info *info = arg;
+	struct snd_seq_client_port *port;
+
+	if (info->addr.client != client->number) /* only set our own ports ! */
+		return -EPERM;
+	port = snd_seq_port_use_ptr(client, info->addr.port);
+	if (port) {
+		snd_seq_set_port_info(port, info);
+		snd_seq_port_unlock(port);
+	}
+	return 0;
+}
+
+
+/*
+ * port subscription (connection)
+ */
+#define PERM_RD		(SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ)
+#define PERM_WR		(SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_SUBS_WRITE)
+
+static int check_subscription_permission(struct snd_seq_client *client,
+					 struct snd_seq_client_port *sport,
+					 struct snd_seq_client_port *dport,
+					 struct snd_seq_port_subscribe *subs)
+{
+	if (client->number != subs->sender.client &&
+	    client->number != subs->dest.client) {
+		/* connection by third client - check export permission */
+		if (check_port_perm(sport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
+			return -EPERM;
+		if (check_port_perm(dport, SNDRV_SEQ_PORT_CAP_NO_EXPORT))
+			return -EPERM;
+	}
+
+	/* check read permission */
+	/* if sender or receiver is the subscribing client itself,
+	 * no permission check is necessary
+	 */
+	if (client->number != subs->sender.client) {
+		if (! check_port_perm(sport, PERM_RD))
+			return -EPERM;
+	}
+	/* check write permission */
+	if (client->number != subs->dest.client) {
+		if (! check_port_perm(dport, PERM_WR))
+			return -EPERM;
+	}
+	return 0;
+}
+
+/*
+ * send an subscription notify event to user client:
+ * client must be user client.
+ */
+int snd_seq_client_notify_subscription(int client, int port,
+				       struct snd_seq_port_subscribe *info,
+				       int evtype)
+{
+	struct snd_seq_event event;
+
+	memset(&event, 0, sizeof(event));
+	event.type = evtype;
+	event.data.connect.dest = info->dest;
+	event.data.connect.sender = info->sender;
+
+	return snd_seq_system_notify(client, port, &event);  /* non-atomic */
+}
+
+
+/* 
+ * add to port's subscription list IOCTL interface 
+ */
+static int snd_seq_ioctl_subscribe_port(struct snd_seq_client *client,
+					void *arg)
+{
+	struct snd_seq_port_subscribe *subs = arg;
+	int result = -EINVAL;
+	struct snd_seq_client *receiver = NULL, *sender = NULL;
+	struct snd_seq_client_port *sport = NULL, *dport = NULL;
+
+	receiver = snd_seq_client_use_ptr(subs->dest.client);
+	if (!receiver)
+		goto __end;
+	sender = snd_seq_client_use_ptr(subs->sender.client);
+	if (!sender)
+		goto __end;
+	sport = snd_seq_port_use_ptr(sender, subs->sender.port);
+	if (!sport)
+		goto __end;
+	dport = snd_seq_port_use_ptr(receiver, subs->dest.port);
+	if (!dport)
+		goto __end;
+
+	result = check_subscription_permission(client, sport, dport, subs);
+	if (result < 0)
+		goto __end;
+
+	/* connect them */
+	result = snd_seq_port_connect(client, sender, sport, receiver, dport, subs);
+	if (! result) /* broadcast announce */
+		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
+						   subs, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
+      __end:
+      	if (sport)
+		snd_seq_port_unlock(sport);
+	if (dport)
+		snd_seq_port_unlock(dport);
+	if (sender)
+		snd_seq_client_unlock(sender);
+	if (receiver)
+		snd_seq_client_unlock(receiver);
+	return result;
+}
+
+
+/* 
+ * remove from port's subscription list 
+ */
+static int snd_seq_ioctl_unsubscribe_port(struct snd_seq_client *client,
+					  void *arg)
+{
+	struct snd_seq_port_subscribe *subs = arg;
+	int result = -ENXIO;
+	struct snd_seq_client *receiver = NULL, *sender = NULL;
+	struct snd_seq_client_port *sport = NULL, *dport = NULL;
+
+	receiver = snd_seq_client_use_ptr(subs->dest.client);
+	if (!receiver)
+		goto __end;
+	sender = snd_seq_client_use_ptr(subs->sender.client);
+	if (!sender)
+		goto __end;
+	sport = snd_seq_port_use_ptr(sender, subs->sender.port);
+	if (!sport)
+		goto __end;
+	dport = snd_seq_port_use_ptr(receiver, subs->dest.port);
+	if (!dport)
+		goto __end;
+
+	result = check_subscription_permission(client, sport, dport, subs);
+	if (result < 0)
+		goto __end;
+
+	result = snd_seq_port_disconnect(client, sender, sport, receiver, dport, subs);
+	if (! result) /* broadcast announce */
+		snd_seq_client_notify_subscription(SNDRV_SEQ_ADDRESS_SUBSCRIBERS, 0,
+						   subs, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
+      __end:
+      	if (sport)
+		snd_seq_port_unlock(sport);
+	if (dport)
+		snd_seq_port_unlock(dport);
+	if (sender)
+		snd_seq_client_unlock(sender);
+	if (receiver)
+		snd_seq_client_unlock(receiver);
+	return result;
+}
+
+
+/* CREATE_QUEUE ioctl() */
+static int snd_seq_ioctl_create_queue(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_queue_info *info = arg;
+	struct snd_seq_queue *q;
+
+	q = snd_seq_queue_alloc(client->number, info->locked, info->flags);
+	if (IS_ERR(q))
+		return PTR_ERR(q);
+
+	info->queue = q->queue;
+	info->locked = q->locked;
+	info->owner = q->owner;
+
+	/* set queue name */
+	if (!info->name[0])
+		snprintf(info->name, sizeof(info->name), "Queue-%d", q->queue);
+	strscpy(q->name, info->name, sizeof(q->name));
+	snd_use_lock_free(&q->use_lock);
+
+	return 0;
+}
+
+/* DELETE_QUEUE ioctl() */
+static int snd_seq_ioctl_delete_queue(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_queue_info *info = arg;
+
+	return snd_seq_queue_delete(client->number, info->queue);
+}
+
+/* GET_QUEUE_INFO ioctl() */
+static int snd_seq_ioctl_get_queue_info(struct snd_seq_client *client,
+					void *arg)
+{
+	struct snd_seq_queue_info *info = arg;
+	struct snd_seq_queue *q;
+
+	q = queueptr(info->queue);
+	if (q == NULL)
+		return -EINVAL;
+
+	memset(info, 0, sizeof(*info));
+	info->queue = q->queue;
+	info->owner = q->owner;
+	info->locked = q->locked;
+	strscpy(info->name, q->name, sizeof(info->name));
+	queuefree(q);
+
+	return 0;
+}
+
+/* SET_QUEUE_INFO ioctl() */
+static int snd_seq_ioctl_set_queue_info(struct snd_seq_client *client,
+					void *arg)
+{
+	struct snd_seq_queue_info *info = arg;
+	struct snd_seq_queue *q;
+
+	if (info->owner != client->number)
+		return -EINVAL;
+
+	/* change owner/locked permission */
+	if (snd_seq_queue_check_access(info->queue, client->number)) {
+		if (snd_seq_queue_set_owner(info->queue, client->number, info->locked) < 0)
+			return -EPERM;
+		if (info->locked)
+			snd_seq_queue_use(info->queue, client->number, 1);
+	} else {
+		return -EPERM;
+	}	
+
+	q = queueptr(info->queue);
+	if (! q)
+		return -EINVAL;
+	if (q->owner != client->number) {
+		queuefree(q);
+		return -EPERM;
+	}
+	strscpy(q->name, info->name, sizeof(q->name));
+	queuefree(q);
+
+	return 0;
+}
+
+/* GET_NAMED_QUEUE ioctl() */
+static int snd_seq_ioctl_get_named_queue(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_queue_info *info = arg;
+	struct snd_seq_queue *q;
+
+	q = snd_seq_queue_find_name(info->name);
+	if (q == NULL)
+		return -EINVAL;
+	info->queue = q->queue;
+	info->owner = q->owner;
+	info->locked = q->locked;
+	queuefree(q);
+
+	return 0;
+}
+
+/* GET_QUEUE_STATUS ioctl() */
+static int snd_seq_ioctl_get_queue_status(struct snd_seq_client *client,
+					  void *arg)
+{
+	struct snd_seq_queue_status *status = arg;
+	struct snd_seq_queue *queue;
+	struct snd_seq_timer *tmr;
+
+	queue = queueptr(status->queue);
+	if (queue == NULL)
+		return -EINVAL;
+	memset(status, 0, sizeof(*status));
+	status->queue = queue->queue;
+	
+	tmr = queue->timer;
+	status->events = queue->tickq->cells + queue->timeq->cells;
+
+	status->time = snd_seq_timer_get_cur_time(tmr, true);
+	status->tick = snd_seq_timer_get_cur_tick(tmr);
+
+	status->running = tmr->running;
+
+	status->flags = queue->flags;
+	queuefree(queue);
+
+	return 0;
+}
+
+
+/* GET_QUEUE_TEMPO ioctl() */
+static int snd_seq_ioctl_get_queue_tempo(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_queue_tempo *tempo = arg;
+	struct snd_seq_queue *queue;
+	struct snd_seq_timer *tmr;
+
+	queue = queueptr(tempo->queue);
+	if (queue == NULL)
+		return -EINVAL;
+	memset(tempo, 0, sizeof(*tempo));
+	tempo->queue = queue->queue;
+	
+	tmr = queue->timer;
+
+	tempo->tempo = tmr->tempo;
+	tempo->ppq = tmr->ppq;
+	tempo->skew_value = tmr->skew;
+	tempo->skew_base = tmr->skew_base;
+	queuefree(queue);
+
+	return 0;
+}
+
+
+/* SET_QUEUE_TEMPO ioctl() */
+int snd_seq_set_queue_tempo(int client, struct snd_seq_queue_tempo *tempo)
+{
+	if (!snd_seq_queue_check_access(tempo->queue, client))
+		return -EPERM;
+	return snd_seq_queue_timer_set_tempo(tempo->queue, client, tempo);
+}
+EXPORT_SYMBOL(snd_seq_set_queue_tempo);
+
+static int snd_seq_ioctl_set_queue_tempo(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_queue_tempo *tempo = arg;
+	int result;
+
+	result = snd_seq_set_queue_tempo(client->number, tempo);
+	return result < 0 ? result : 0;
+}
+
+
+/* GET_QUEUE_TIMER ioctl() */
+static int snd_seq_ioctl_get_queue_timer(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_queue_timer *timer = arg;
+	struct snd_seq_queue *queue;
+	struct snd_seq_timer *tmr;
+
+	queue = queueptr(timer->queue);
+	if (queue == NULL)
+		return -EINVAL;
+
+	mutex_lock(&queue->timer_mutex);
+	tmr = queue->timer;
+	memset(timer, 0, sizeof(*timer));
+	timer->queue = queue->queue;
+
+	timer->type = tmr->type;
+	if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
+		timer->u.alsa.id = tmr->alsa_id;
+		timer->u.alsa.resolution = tmr->preferred_resolution;
+	}
+	mutex_unlock(&queue->timer_mutex);
+	queuefree(queue);
+	
+	return 0;
+}
+
+
+/* SET_QUEUE_TIMER ioctl() */
+static int snd_seq_ioctl_set_queue_timer(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_queue_timer *timer = arg;
+	int result = 0;
+
+	if (timer->type != SNDRV_SEQ_TIMER_ALSA)
+		return -EINVAL;
+
+	if (snd_seq_queue_check_access(timer->queue, client->number)) {
+		struct snd_seq_queue *q;
+		struct snd_seq_timer *tmr;
+
+		q = queueptr(timer->queue);
+		if (q == NULL)
+			return -ENXIO;
+		mutex_lock(&q->timer_mutex);
+		tmr = q->timer;
+		snd_seq_queue_timer_close(timer->queue);
+		tmr->type = timer->type;
+		if (tmr->type == SNDRV_SEQ_TIMER_ALSA) {
+			tmr->alsa_id = timer->u.alsa.id;
+			tmr->preferred_resolution = timer->u.alsa.resolution;
+		}
+		result = snd_seq_queue_timer_open(timer->queue);
+		mutex_unlock(&q->timer_mutex);
+		queuefree(q);
+	} else {
+		return -EPERM;
+	}	
+
+	return result;
+}
+
+
+/* GET_QUEUE_CLIENT ioctl() */
+static int snd_seq_ioctl_get_queue_client(struct snd_seq_client *client,
+					  void *arg)
+{
+	struct snd_seq_queue_client *info = arg;
+	int used;
+
+	used = snd_seq_queue_is_used(info->queue, client->number);
+	if (used < 0)
+		return -EINVAL;
+	info->used = used;
+	info->client = client->number;
+
+	return 0;
+}
+
+
+/* SET_QUEUE_CLIENT ioctl() */
+static int snd_seq_ioctl_set_queue_client(struct snd_seq_client *client,
+					  void *arg)
+{
+	struct snd_seq_queue_client *info = arg;
+	int err;
+
+	if (info->used >= 0) {
+		err = snd_seq_queue_use(info->queue, client->number, info->used);
+		if (err < 0)
+			return err;
+	}
+
+	return snd_seq_ioctl_get_queue_client(client, arg);
+}
+
+
+/* GET_CLIENT_POOL ioctl() */
+static int snd_seq_ioctl_get_client_pool(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_client_pool *info = arg;
+	struct snd_seq_client *cptr;
+
+	cptr = snd_seq_client_use_ptr(info->client);
+	if (cptr == NULL)
+		return -ENOENT;
+	memset(info, 0, sizeof(*info));
+	info->client = cptr->number;
+	info->output_pool = cptr->pool->size;
+	info->output_room = cptr->pool->room;
+	info->output_free = info->output_pool;
+	info->output_free = snd_seq_unused_cells(cptr->pool);
+	if (cptr->type == USER_CLIENT) {
+		info->input_pool = cptr->data.user.fifo_pool_size;
+		info->input_free = info->input_pool;
+		info->input_free = snd_seq_fifo_unused_cells(cptr->data.user.fifo);
+	} else {
+		info->input_pool = 0;
+		info->input_free = 0;
+	}
+	snd_seq_client_unlock(cptr);
+	
+	return 0;
+}
+
+/* SET_CLIENT_POOL ioctl() */
+static int snd_seq_ioctl_set_client_pool(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_client_pool *info = arg;
+	int rc;
+
+	if (client->number != info->client)
+		return -EINVAL; /* can't change other clients */
+
+	if (info->output_pool >= 1 && info->output_pool <= SNDRV_SEQ_MAX_EVENTS &&
+	    (! snd_seq_write_pool_allocated(client) ||
+	     info->output_pool != client->pool->size)) {
+		if (snd_seq_write_pool_allocated(client)) {
+			/* is the pool in use? */
+			if (atomic_read(&client->pool->counter))
+				return -EBUSY;
+			/* remove all existing cells */
+			snd_seq_pool_mark_closing(client->pool);
+			snd_seq_pool_done(client->pool);
+		}
+		client->pool->size = info->output_pool;
+		rc = snd_seq_pool_init(client->pool);
+		if (rc < 0)
+			return rc;
+	}
+	if (client->type == USER_CLIENT && client->data.user.fifo != NULL &&
+	    info->input_pool >= 1 &&
+	    info->input_pool <= SNDRV_SEQ_MAX_CLIENT_EVENTS &&
+	    info->input_pool != client->data.user.fifo_pool_size) {
+		/* change pool size */
+		rc = snd_seq_fifo_resize(client->data.user.fifo, info->input_pool);
+		if (rc < 0)
+			return rc;
+		client->data.user.fifo_pool_size = info->input_pool;
+	}
+	if (info->output_room >= 1 &&
+	    info->output_room <= client->pool->size) {
+		client->pool->room  = info->output_room;
+	}
+
+	return snd_seq_ioctl_get_client_pool(client, arg);
+}
+
+
+/* REMOVE_EVENTS ioctl() */
+static int snd_seq_ioctl_remove_events(struct snd_seq_client *client,
+				       void *arg)
+{
+	struct snd_seq_remove_events *info = arg;
+
+	/*
+	 * Input mostly not implemented XXX.
+	 */
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_INPUT) {
+		/*
+		 * No restrictions so for a user client we can clear
+		 * the whole fifo
+		 */
+		if (client->type == USER_CLIENT && client->data.user.fifo)
+			snd_seq_fifo_clear(client->data.user.fifo);
+	}
+
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_OUTPUT)
+		snd_seq_queue_remove_cells(client->number, info);
+
+	return 0;
+}
+
+
+/*
+ * get subscription info
+ */
+static int snd_seq_ioctl_get_subscription(struct snd_seq_client *client,
+					  void *arg)
+{
+	struct snd_seq_port_subscribe *subs = arg;
+	int result;
+	struct snd_seq_client *sender = NULL;
+	struct snd_seq_client_port *sport = NULL;
+
+	result = -EINVAL;
+	sender = snd_seq_client_use_ptr(subs->sender.client);
+	if (!sender)
+		goto __end;
+	sport = snd_seq_port_use_ptr(sender, subs->sender.port);
+	if (!sport)
+		goto __end;
+	result = snd_seq_port_get_subscription(&sport->c_src, &subs->dest,
+					       subs);
+      __end:
+      	if (sport)
+		snd_seq_port_unlock(sport);
+	if (sender)
+		snd_seq_client_unlock(sender);
+
+	return result;
+}
+
+
+/*
+ * get subscription info - check only its presence
+ */
+static int snd_seq_ioctl_query_subs(struct snd_seq_client *client, void *arg)
+{
+	struct snd_seq_query_subs *subs = arg;
+	int result = -ENXIO;
+	struct snd_seq_client *cptr = NULL;
+	struct snd_seq_client_port *port = NULL;
+	struct snd_seq_port_subs_info *group;
+	struct list_head *p;
+	int i;
+
+	cptr = snd_seq_client_use_ptr(subs->root.client);
+	if (!cptr)
+		goto __end;
+	port = snd_seq_port_use_ptr(cptr, subs->root.port);
+	if (!port)
+		goto __end;
+
+	switch (subs->type) {
+	case SNDRV_SEQ_QUERY_SUBS_READ:
+		group = &port->c_src;
+		break;
+	case SNDRV_SEQ_QUERY_SUBS_WRITE:
+		group = &port->c_dest;
+		break;
+	default:
+		goto __end;
+	}
+
+	down_read(&group->list_mutex);
+	/* search for the subscriber */
+	subs->num_subs = group->count;
+	i = 0;
+	result = -ENOENT;
+	list_for_each(p, &group->list_head) {
+		if (i++ == subs->index) {
+			/* found! */
+			struct snd_seq_subscribers *s;
+			if (subs->type == SNDRV_SEQ_QUERY_SUBS_READ) {
+				s = list_entry(p, struct snd_seq_subscribers, src_list);
+				subs->addr = s->info.dest;
+			} else {
+				s = list_entry(p, struct snd_seq_subscribers, dest_list);
+				subs->addr = s->info.sender;
+			}
+			subs->flags = s->info.flags;
+			subs->queue = s->info.queue;
+			result = 0;
+			break;
+		}
+	}
+	up_read(&group->list_mutex);
+
+      __end:
+   	if (port)
+		snd_seq_port_unlock(port);
+	if (cptr)
+		snd_seq_client_unlock(cptr);
+
+	return result;
+}
+
+
+/*
+ * query next client
+ */
+static int snd_seq_ioctl_query_next_client(struct snd_seq_client *client,
+					   void *arg)
+{
+	struct snd_seq_client_info *info = arg;
+	struct snd_seq_client *cptr = NULL;
+
+	/* search for next client */
+	if (info->client < INT_MAX)
+		info->client++;
+	if (info->client < 0)
+		info->client = 0;
+	for (; info->client < SNDRV_SEQ_MAX_CLIENTS; info->client++) {
+		cptr = snd_seq_client_use_ptr(info->client);
+		if (cptr)
+			break; /* found */
+	}
+	if (cptr == NULL)
+		return -ENOENT;
+
+	get_client_info(cptr, info);
+	snd_seq_client_unlock(cptr);
+
+	return 0;
+}
+
+/* 
+ * query next port
+ */
+static int snd_seq_ioctl_query_next_port(struct snd_seq_client *client,
+					 void *arg)
+{
+	struct snd_seq_port_info *info = arg;
+	struct snd_seq_client *cptr;
+	struct snd_seq_client_port *port = NULL;
+
+	cptr = snd_seq_client_use_ptr(info->addr.client);
+	if (cptr == NULL)
+		return -ENXIO;
+
+	/* search for next port */
+	info->addr.port++;
+	port = snd_seq_port_query_nearest(cptr, info);
+	if (port == NULL) {
+		snd_seq_client_unlock(cptr);
+		return -ENOENT;
+	}
+
+	/* get port info */
+	info->addr = port->addr;
+	snd_seq_get_port_info(port, info);
+	snd_seq_port_unlock(port);
+	snd_seq_client_unlock(cptr);
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+#define NUM_UMP_INFOS (SNDRV_UMP_MAX_BLOCKS + 1)
+
+static void free_ump_info(struct snd_seq_client *client)
+{
+	int i;
+
+	if (!client->ump_info)
+		return;
+	for (i = 0; i < NUM_UMP_INFOS; i++)
+		kfree(client->ump_info[i]);
+	kfree(client->ump_info);
+	client->ump_info = NULL;
+}
+
+static void terminate_ump_info_strings(void *p, int type)
+{
+	if (type == SNDRV_SEQ_CLIENT_UMP_INFO_ENDPOINT) {
+		struct snd_ump_endpoint_info *ep = p;
+		ep->name[sizeof(ep->name) - 1] = 0;
+	} else {
+		struct snd_ump_block_info *bp = p;
+		bp->name[sizeof(bp->name) - 1] = 0;
+	}
+}
+
+#ifdef CONFIG_SND_PROC_FS
+static void dump_ump_info(struct snd_info_buffer *buffer,
+			  struct snd_seq_client *client)
+{
+	struct snd_ump_endpoint_info *ep;
+	struct snd_ump_block_info *bp;
+	int i;
+
+	if (!client->ump_info)
+		return;
+	ep = client->ump_info[SNDRV_SEQ_CLIENT_UMP_INFO_ENDPOINT];
+	if (ep && *ep->name)
+		snd_iprintf(buffer, "  UMP Endpoint: \"%s\"\n", ep->name);
+	for (i = 0; i < SNDRV_UMP_MAX_BLOCKS; i++) {
+		bp = client->ump_info[i + 1];
+		if (bp && *bp->name) {
+			snd_iprintf(buffer, "  UMP Block %d: \"%s\" [%s]\n",
+				    i, bp->name,
+				    bp->active ? "Active" : "Inactive");
+			snd_iprintf(buffer, "    Groups: %d-%d\n",
+				    bp->first_group + 1,
+				    bp->first_group + bp->num_groups);
+		}
+	}
+}
+#endif
+
+/* UMP-specific ioctls -- called directly without data copy */
+static int snd_seq_ioctl_client_ump_info(struct snd_seq_client *caller,
+					 unsigned int cmd,
+					 unsigned long arg)
+{
+	struct snd_seq_client_ump_info __user *argp =
+		(struct snd_seq_client_ump_info __user *)arg;
+	struct snd_seq_client *cptr;
+	int client, type, err = 0;
+	size_t size;
+	void *p;
+
+	if (get_user(client, &argp->client) || get_user(type, &argp->type))
+		return -EFAULT;
+	if (cmd == SNDRV_SEQ_IOCTL_SET_CLIENT_UMP_INFO &&
+	    caller->number != client)
+		return -EPERM;
+	if (type < 0 || type >= NUM_UMP_INFOS)
+		return -EINVAL;
+	if (type == SNDRV_SEQ_CLIENT_UMP_INFO_ENDPOINT)
+		size = sizeof(struct snd_ump_endpoint_info);
+	else
+		size = sizeof(struct snd_ump_block_info);
+	cptr = snd_seq_client_use_ptr(client);
+	if (!cptr)
+		return -ENOENT;
+
+	mutex_lock(&cptr->ioctl_mutex);
+	if (!cptr->midi_version) {
+		err = -EBADFD;
+		goto error;
+	}
+
+	if (cmd == SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO) {
+		if (!cptr->ump_info)
+			p = NULL;
+		else
+			p = cptr->ump_info[type];
+		if (!p) {
+			err = -ENODEV;
+			goto error;
+		}
+		if (copy_to_user(argp->info, p, size)) {
+			err = -EFAULT;
+			goto error;
+		}
+	} else {
+		if (cptr->type != USER_CLIENT) {
+			err = -EBADFD;
+			goto error;
+		}
+		if (!cptr->ump_info) {
+			cptr->ump_info = kcalloc(NUM_UMP_INFOS,
+						 sizeof(void *), GFP_KERNEL);
+			if (!cptr->ump_info) {
+				err = -ENOMEM;
+				goto error;
+			}
+		}
+		p = memdup_user(argp->info, size);
+		if (IS_ERR(p)) {
+			err = PTR_ERR(p);
+			goto error;
+		}
+		kfree(cptr->ump_info[type]);
+		terminate_ump_info_strings(p, type);
+		cptr->ump_info[type] = p;
+	}
+
+ error:
+	mutex_unlock(&cptr->ioctl_mutex);
+	snd_seq_client_unlock(cptr);
+	return err;
+}
+#endif
+
+/* -------------------------------------------------------- */
+
+static const struct ioctl_handler {
+	unsigned int cmd;
+	int (*func)(struct snd_seq_client *client, void *arg);
+} ioctl_handlers[] = {
+	{ SNDRV_SEQ_IOCTL_PVERSION, snd_seq_ioctl_pversion },
+	{ SNDRV_SEQ_IOCTL_USER_PVERSION, snd_seq_ioctl_user_pversion },
+	{ SNDRV_SEQ_IOCTL_CLIENT_ID, snd_seq_ioctl_client_id },
+	{ SNDRV_SEQ_IOCTL_SYSTEM_INFO, snd_seq_ioctl_system_info },
+	{ SNDRV_SEQ_IOCTL_RUNNING_MODE, snd_seq_ioctl_running_mode },
+	{ SNDRV_SEQ_IOCTL_GET_CLIENT_INFO, snd_seq_ioctl_get_client_info },
+	{ SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, snd_seq_ioctl_set_client_info },
+	{ SNDRV_SEQ_IOCTL_CREATE_PORT, snd_seq_ioctl_create_port },
+	{ SNDRV_SEQ_IOCTL_DELETE_PORT, snd_seq_ioctl_delete_port },
+	{ SNDRV_SEQ_IOCTL_GET_PORT_INFO, snd_seq_ioctl_get_port_info },
+	{ SNDRV_SEQ_IOCTL_SET_PORT_INFO, snd_seq_ioctl_set_port_info },
+	{ SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, snd_seq_ioctl_subscribe_port },
+	{ SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, snd_seq_ioctl_unsubscribe_port },
+	{ SNDRV_SEQ_IOCTL_CREATE_QUEUE, snd_seq_ioctl_create_queue },
+	{ SNDRV_SEQ_IOCTL_DELETE_QUEUE, snd_seq_ioctl_delete_queue },
+	{ SNDRV_SEQ_IOCTL_GET_QUEUE_INFO, snd_seq_ioctl_get_queue_info },
+	{ SNDRV_SEQ_IOCTL_SET_QUEUE_INFO, snd_seq_ioctl_set_queue_info },
+	{ SNDRV_SEQ_IOCTL_GET_NAMED_QUEUE, snd_seq_ioctl_get_named_queue },
+	{ SNDRV_SEQ_IOCTL_GET_QUEUE_STATUS, snd_seq_ioctl_get_queue_status },
+	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO, snd_seq_ioctl_get_queue_tempo },
+	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO, snd_seq_ioctl_set_queue_tempo },
+	{ SNDRV_SEQ_IOCTL_GET_QUEUE_TIMER, snd_seq_ioctl_get_queue_timer },
+	{ SNDRV_SEQ_IOCTL_SET_QUEUE_TIMER, snd_seq_ioctl_set_queue_timer },
+	{ SNDRV_SEQ_IOCTL_GET_QUEUE_CLIENT, snd_seq_ioctl_get_queue_client },
+	{ SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT, snd_seq_ioctl_set_queue_client },
+	{ SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, snd_seq_ioctl_get_client_pool },
+	{ SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, snd_seq_ioctl_set_client_pool },
+	{ SNDRV_SEQ_IOCTL_GET_SUBSCRIPTION, snd_seq_ioctl_get_subscription },
+	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT, snd_seq_ioctl_query_next_client },
+	{ SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, snd_seq_ioctl_query_next_port },
+	{ SNDRV_SEQ_IOCTL_REMOVE_EVENTS, snd_seq_ioctl_remove_events },
+	{ SNDRV_SEQ_IOCTL_QUERY_SUBS, snd_seq_ioctl_query_subs },
+	{ 0, NULL },
+};
+
+static long snd_seq_ioctl(struct file *file, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct snd_seq_client *client = file->private_data;
+	/* To use kernel stack for ioctl data. */
+	union {
+		int pversion;
+		int client_id;
+		struct snd_seq_system_info	system_info;
+		struct snd_seq_running_info	running_info;
+		struct snd_seq_client_info	client_info;
+		struct snd_seq_port_info	port_info;
+		struct snd_seq_port_subscribe	port_subscribe;
+		struct snd_seq_queue_info	queue_info;
+		struct snd_seq_queue_status	queue_status;
+		struct snd_seq_queue_tempo	tempo;
+		struct snd_seq_queue_timer	queue_timer;
+		struct snd_seq_queue_client	queue_client;
+		struct snd_seq_client_pool	client_pool;
+		struct snd_seq_remove_events	remove_events;
+		struct snd_seq_query_subs	query_subs;
+	} buf;
+	const struct ioctl_handler *handler;
+	unsigned long size;
+	int err;
+
+	if (snd_BUG_ON(!client))
+		return -ENXIO;
+
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+	/* exception - handling large data */
+	switch (cmd) {
+	case SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO:
+	case SNDRV_SEQ_IOCTL_SET_CLIENT_UMP_INFO:
+		return snd_seq_ioctl_client_ump_info(client, cmd, arg);
+	}
+#endif
+
+	for (handler = ioctl_handlers; handler->cmd > 0; ++handler) {
+		if (handler->cmd == cmd)
+			break;
+	}
+	if (handler->cmd == 0)
+		return -ENOTTY;
+
+	memset(&buf, 0, sizeof(buf));
+
+	/*
+	 * All of ioctl commands for ALSA sequencer get an argument of size
+	 * within 13 bits. We can safely pick up the size from the command.
+	 */
+	size = _IOC_SIZE(handler->cmd);
+	if (handler->cmd & IOC_IN) {
+		if (copy_from_user(&buf, (const void __user *)arg, size))
+			return -EFAULT;
+	}
+
+	mutex_lock(&client->ioctl_mutex);
+	err = handler->func(client, &buf);
+	mutex_unlock(&client->ioctl_mutex);
+	if (err >= 0) {
+		/* Some commands includes a bug in 'dir' field. */
+		if (handler->cmd == SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT ||
+		    handler->cmd == SNDRV_SEQ_IOCTL_SET_CLIENT_POOL ||
+		    (handler->cmd & IOC_OUT))
+			if (copy_to_user((void __user *)arg, &buf, size))
+				return -EFAULT;
+	}
+
+	return err;
+}
+
+#ifdef CONFIG_COMPAT
+#include "seq_compat.c"
+#else
+#define snd_seq_ioctl_compat	NULL
+#endif
+
+/* -------------------------------------------------------- */
+
+
+/* exported to kernel modules */
+int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
+				 const char *name_fmt, ...)
+{
+	struct snd_seq_client *client;
+	va_list args;
+
+	if (snd_BUG_ON(in_interrupt()))
+		return -EBUSY;
+
+	if (card && client_index >= SNDRV_SEQ_CLIENTS_PER_CARD)
+		return -EINVAL;
+	if (card == NULL && client_index >= SNDRV_SEQ_GLOBAL_CLIENTS)
+		return -EINVAL;
+
+	mutex_lock(&register_mutex);
+
+	if (card) {
+		client_index += SNDRV_SEQ_GLOBAL_CLIENTS
+			+ card->number * SNDRV_SEQ_CLIENTS_PER_CARD;
+		if (client_index >= SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN)
+			client_index = -1;
+	}
+
+	/* empty write queue as default */
+	client = seq_create_client1(client_index, 0);
+	if (client == NULL) {
+		mutex_unlock(&register_mutex);
+		return -EBUSY;	/* failure code */
+	}
+	usage_alloc(&client_usage, 1);
+
+	client->accept_input = 1;
+	client->accept_output = 1;
+	client->data.kernel.card = card;
+	client->user_pversion = SNDRV_SEQ_VERSION;
+		
+	va_start(args, name_fmt);
+	vsnprintf(client->name, sizeof(client->name), name_fmt, args);
+	va_end(args);
+
+	client->type = KERNEL_CLIENT;
+	mutex_unlock(&register_mutex);
+
+	/* make others aware this new client */
+	snd_seq_system_client_ev_client_start(client->number);
+	
+	/* return client number to caller */
+	return client->number;
+}
+EXPORT_SYMBOL(snd_seq_create_kernel_client);
+
+/* exported to kernel modules */
+int snd_seq_delete_kernel_client(int client)
+{
+	struct snd_seq_client *ptr;
+
+	if (snd_BUG_ON(in_interrupt()))
+		return -EBUSY;
+
+	ptr = clientptr(client);
+	if (ptr == NULL)
+		return -EINVAL;
+
+	seq_free_client(ptr);
+	kfree(ptr);
+	return 0;
+}
+EXPORT_SYMBOL(snd_seq_delete_kernel_client);
+
+/*
+ * exported, called by kernel clients to enqueue events (w/o blocking)
+ *
+ * RETURN VALUE: zero if succeed, negative if error
+ */
+int snd_seq_kernel_client_enqueue(int client, struct snd_seq_event *ev,
+				  struct file *file, bool blocking)
+{
+	struct snd_seq_client *cptr;
+	int result;
+
+	if (snd_BUG_ON(!ev))
+		return -EINVAL;
+
+	if (!snd_seq_ev_is_ump(ev)) {
+		if (ev->type == SNDRV_SEQ_EVENT_NONE)
+			return 0; /* ignore this */
+		if (ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
+			return -EINVAL; /* quoted events can't be enqueued */
+	}
+
+	/* fill in client number */
+	ev->source.client = client;
+
+	if (check_event_type_and_length(ev))
+		return -EINVAL;
+
+	cptr = snd_seq_client_use_ptr(client);
+	if (cptr == NULL)
+		return -EINVAL;
+	
+	if (!cptr->accept_output) {
+		result = -EPERM;
+	} else { /* send it */
+		mutex_lock(&cptr->ioctl_mutex);
+		result = snd_seq_client_enqueue_event(cptr, ev, file, blocking,
+						      false, 0,
+						      &cptr->ioctl_mutex);
+		mutex_unlock(&cptr->ioctl_mutex);
+	}
+
+	snd_seq_client_unlock(cptr);
+	return result;
+}
+EXPORT_SYMBOL(snd_seq_kernel_client_enqueue);
+
+/* 
+ * exported, called by kernel clients to dispatch events directly to other
+ * clients, bypassing the queues.  Event time-stamp will be updated.
+ *
+ * RETURN VALUE: negative = delivery failed,
+ *		 zero, or positive: the number of delivered events
+ */
+int snd_seq_kernel_client_dispatch(int client, struct snd_seq_event * ev,
+				   int atomic, int hop)
+{
+	struct snd_seq_client *cptr;
+	int result;
+
+	if (snd_BUG_ON(!ev))
+		return -EINVAL;
+
+	/* fill in client number */
+	ev->queue = SNDRV_SEQ_QUEUE_DIRECT;
+	ev->source.client = client;
+
+	if (check_event_type_and_length(ev))
+		return -EINVAL;
+
+	cptr = snd_seq_client_use_ptr(client);
+	if (cptr == NULL)
+		return -EINVAL;
+
+	if (!cptr->accept_output)
+		result = -EPERM;
+	else
+		result = snd_seq_deliver_event(cptr, ev, atomic, hop);
+
+	snd_seq_client_unlock(cptr);
+	return result;
+}
+EXPORT_SYMBOL(snd_seq_kernel_client_dispatch);
+
+/**
+ * snd_seq_kernel_client_ctl - operate a command for a client with data in
+ *			       kernel space.
+ * @clientid:	A numerical ID for a client.
+ * @cmd:	An ioctl(2) command for ALSA sequencer operation.
+ * @arg:	A pointer to data in kernel space.
+ *
+ * Against its name, both kernel/application client can be handled by this
+ * kernel API. A pointer of 'arg' argument should be in kernel space.
+ *
+ * Return: 0 at success. Negative error code at failure.
+ */
+int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg)
+{
+	const struct ioctl_handler *handler;
+	struct snd_seq_client *client;
+
+	client = clientptr(clientid);
+	if (client == NULL)
+		return -ENXIO;
+
+	for (handler = ioctl_handlers; handler->cmd > 0; ++handler) {
+		if (handler->cmd == cmd)
+			return handler->func(client, arg);
+	}
+
+	pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n",
+		 cmd, _IOC_TYPE(cmd), _IOC_NR(cmd));
+	return -ENOTTY;
+}
+EXPORT_SYMBOL(snd_seq_kernel_client_ctl);
+
+/* exported (for OSS emulator) */
+int snd_seq_kernel_client_write_poll(int clientid, struct file *file, poll_table *wait)
+{
+	struct snd_seq_client *client;
+
+	client = clientptr(clientid);
+	if (client == NULL)
+		return -ENXIO;
+
+	if (! snd_seq_write_pool_allocated(client))
+		return 1;
+	if (snd_seq_pool_poll_wait(client->pool, file, wait))
+		return 1;
+	return 0;
+}
+EXPORT_SYMBOL(snd_seq_kernel_client_write_poll);
+
+/* get a sequencer client object; for internal use from a kernel client */
+struct snd_seq_client *snd_seq_kernel_client_get(int id)
+{
+	return snd_seq_client_use_ptr(id);
+}
+EXPORT_SYMBOL_GPL(snd_seq_kernel_client_get);
+
+/* put a sequencer client object; for internal use from a kernel client */
+void snd_seq_kernel_client_put(struct snd_seq_client *cptr)
+{
+	if (cptr)
+		snd_seq_client_unlock(cptr);
+}
+EXPORT_SYMBOL_GPL(snd_seq_kernel_client_put);
+
+/*---------------------------------------------------------------------------*/
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ *  /proc interface
+ */
+static void snd_seq_info_dump_subscribers(struct snd_info_buffer *buffer,
+					  struct snd_seq_port_subs_info *group,
+					  int is_src, char *msg)
+{
+	struct list_head *p;
+	struct snd_seq_subscribers *s;
+	int count = 0;
+
+	down_read(&group->list_mutex);
+	if (list_empty(&group->list_head)) {
+		up_read(&group->list_mutex);
+		return;
+	}
+	snd_iprintf(buffer, msg);
+	list_for_each(p, &group->list_head) {
+		if (is_src)
+			s = list_entry(p, struct snd_seq_subscribers, src_list);
+		else
+			s = list_entry(p, struct snd_seq_subscribers, dest_list);
+		if (count++)
+			snd_iprintf(buffer, ", ");
+		snd_iprintf(buffer, "%d:%d",
+			    is_src ? s->info.dest.client : s->info.sender.client,
+			    is_src ? s->info.dest.port : s->info.sender.port);
+		if (s->info.flags & SNDRV_SEQ_PORT_SUBS_TIMESTAMP)
+			snd_iprintf(buffer, "[%c:%d]", ((s->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL) ? 'r' : 't'), s->info.queue);
+		if (group->exclusive)
+			snd_iprintf(buffer, "[ex]");
+	}
+	up_read(&group->list_mutex);
+	snd_iprintf(buffer, "\n");
+}
+
+#define FLAG_PERM_RD(perm) ((perm) & SNDRV_SEQ_PORT_CAP_READ ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_READ ? 'R' : 'r') : '-')
+#define FLAG_PERM_WR(perm) ((perm) & SNDRV_SEQ_PORT_CAP_WRITE ? ((perm) & SNDRV_SEQ_PORT_CAP_SUBS_WRITE ? 'W' : 'w') : '-')
+#define FLAG_PERM_EX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_NO_EXPORT ? '-' : 'e')
+
+#define FLAG_PERM_DUPLEX(perm) ((perm) & SNDRV_SEQ_PORT_CAP_DUPLEX ? 'X' : '-')
+
+static const char *port_direction_name(unsigned char dir)
+{
+	static const char *names[4] = {
+		"-", "In", "Out", "In/Out"
+	};
+
+	if (dir > SNDRV_SEQ_PORT_DIR_BIDIRECTION)
+		return "Invalid";
+	return names[dir];
+}
+
+static void snd_seq_info_dump_ports(struct snd_info_buffer *buffer,
+				    struct snd_seq_client *client)
+{
+	struct snd_seq_client_port *p;
+
+	mutex_lock(&client->ports_mutex);
+	list_for_each_entry(p, &client->ports_list_head, list) {
+		if (p->capability & SNDRV_SEQ_PORT_CAP_INACTIVE)
+			continue;
+		snd_iprintf(buffer, "  Port %3d : \"%s\" (%c%c%c%c) [%s]\n",
+			    p->addr.port, p->name,
+			    FLAG_PERM_RD(p->capability),
+			    FLAG_PERM_WR(p->capability),
+			    FLAG_PERM_EX(p->capability),
+			    FLAG_PERM_DUPLEX(p->capability),
+			    port_direction_name(p->direction));
+		snd_seq_info_dump_subscribers(buffer, &p->c_src, 1, "    Connecting To: ");
+		snd_seq_info_dump_subscribers(buffer, &p->c_dest, 0, "    Connected From: ");
+	}
+	mutex_unlock(&client->ports_mutex);
+}
+
+static const char *midi_version_string(unsigned int version)
+{
+	switch (version) {
+	case SNDRV_SEQ_CLIENT_LEGACY_MIDI:
+		return "Legacy";
+	case SNDRV_SEQ_CLIENT_UMP_MIDI_1_0:
+		return "UMP MIDI1";
+	case SNDRV_SEQ_CLIENT_UMP_MIDI_2_0:
+		return "UMP MIDI2";
+	default:
+		return "Unknown";
+	}
+}
+
+/* exported to seq_info.c */
+void snd_seq_info_clients_read(struct snd_info_entry *entry, 
+			       struct snd_info_buffer *buffer)
+{
+	int c;
+	struct snd_seq_client *client;
+
+	snd_iprintf(buffer, "Client info\n");
+	snd_iprintf(buffer, "  cur  clients : %d\n", client_usage.cur);
+	snd_iprintf(buffer, "  peak clients : %d\n", client_usage.peak);
+	snd_iprintf(buffer, "  max  clients : %d\n", SNDRV_SEQ_MAX_CLIENTS);
+	snd_iprintf(buffer, "\n");
+
+	/* list the client table */
+	for (c = 0; c < SNDRV_SEQ_MAX_CLIENTS; c++) {
+		client = snd_seq_client_use_ptr(c);
+		if (client == NULL)
+			continue;
+		if (client->type == NO_CLIENT) {
+			snd_seq_client_unlock(client);
+			continue;
+		}
+
+		snd_iprintf(buffer, "Client %3d : \"%s\" [%s %s]\n",
+			    c, client->name,
+			    client->type == USER_CLIENT ? "User" : "Kernel",
+			    midi_version_string(client->midi_version));
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+		dump_ump_info(buffer, client);
+#endif
+		snd_seq_info_dump_ports(buffer, client);
+		if (snd_seq_write_pool_allocated(client)) {
+			snd_iprintf(buffer, "  Output pool :\n");
+			snd_seq_info_pool(buffer, client->pool, "    ");
+		}
+		if (client->type == USER_CLIENT && client->data.user.fifo &&
+		    client->data.user.fifo->pool) {
+			snd_iprintf(buffer, "  Input pool :\n");
+			snd_seq_info_pool(buffer, client->data.user.fifo->pool, "    ");
+		}
+		snd_seq_client_unlock(client);
+	}
+}
+#endif /* CONFIG_SND_PROC_FS */
+
+/*---------------------------------------------------------------------------*/
+
+
+/*
+ *  REGISTRATION PART
+ */
+
+static const struct file_operations snd_seq_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.read =		snd_seq_read,
+	.write =	snd_seq_write,
+	.open =		snd_seq_open,
+	.release =	snd_seq_release,
+	.llseek =	no_llseek,
+	.poll =		snd_seq_poll,
+	.unlocked_ioctl =	snd_seq_ioctl,
+	.compat_ioctl =	snd_seq_ioctl_compat,
+};
+
+static struct device *seq_dev;
+
+/* 
+ * register sequencer device 
+ */
+int __init snd_sequencer_device_init(void)
+{
+	int err;
+
+	err = snd_device_alloc(&seq_dev, NULL);
+	if (err < 0)
+		return err;
+	dev_set_name(seq_dev, "seq");
+
+	mutex_lock(&register_mutex);
+	err = snd_register_device(SNDRV_DEVICE_TYPE_SEQUENCER, NULL, 0,
+				  &snd_seq_f_ops, NULL, seq_dev);
+	mutex_unlock(&register_mutex);
+	if (err < 0) {
+		put_device(seq_dev);
+		return err;
+	}
+	
+	return 0;
+}
+
+
+
+/* 
+ * unregister sequencer device 
+ */
+void snd_sequencer_device_done(void)
+{
+	snd_unregister_device(seq_dev);
+	put_device(seq_dev);
+}
diff --git a/sound/core/seq/seq_clientmgr.h b/sound/core/seq/seq_clientmgr.h
new file mode 100644
index 0000000000..915b101728
--- /dev/null
+++ b/sound/core/seq/seq_clientmgr.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer Client Manager
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_CLIENTMGR_H
+#define __SND_SEQ_CLIENTMGR_H
+
+#include <sound/seq_kernel.h>
+#include <linux/bitops.h>
+#include "seq_fifo.h"
+#include "seq_ports.h"
+#include "seq_lock.h"
+
+/* client manager */
+
+struct snd_seq_user_client {
+	struct file *file;	/* file struct of client */
+	/* ... */
+	struct pid *owner;
+	
+	/* fifo */
+	struct snd_seq_fifo *fifo;	/* queue for incoming events */
+	int fifo_pool_size;
+};
+
+struct snd_seq_kernel_client {
+	/* ... */
+	struct snd_card *card;
+};
+
+
+struct snd_seq_client {
+	snd_seq_client_type_t type;
+	unsigned int accept_input: 1,
+		accept_output: 1;
+	unsigned int midi_version;
+	unsigned int user_pversion;
+	char name[64];		/* client name */
+	int number;		/* client number */
+	unsigned int filter;	/* filter flags */
+	DECLARE_BITMAP(event_filter, 256);
+	unsigned short group_filter;
+	snd_use_lock_t use_lock;
+	int event_lost;
+	/* ports */
+	int num_ports;		/* number of ports */
+	struct list_head ports_list_head;
+	rwlock_t ports_lock;
+	struct mutex ports_mutex;
+	struct mutex ioctl_mutex;
+	int convert32;		/* convert 32->64bit */
+	int ump_endpoint_port;
+
+	/* output pool */
+	struct snd_seq_pool *pool;		/* memory pool for this client */
+
+	union {
+		struct snd_seq_user_client user;
+		struct snd_seq_kernel_client kernel;
+	} data;
+
+	/* for UMP */
+	void **ump_info;
+};
+
+/* usage statistics */
+struct snd_seq_usage {
+	int cur;
+	int peak;
+};
+
+
+int client_init_data(void);
+int snd_sequencer_device_init(void);
+void snd_sequencer_device_done(void);
+
+/* get locked pointer to client */
+struct snd_seq_client *snd_seq_client_use_ptr(int clientid);
+
+/* unlock pointer to client */
+#define snd_seq_client_unlock(client) snd_use_lock_free(&(client)->use_lock)
+
+/* dispatch event to client(s) */
+int snd_seq_dispatch_event(struct snd_seq_event_cell *cell, int atomic, int hop);
+
+int snd_seq_kernel_client_write_poll(int clientid, struct file *file, poll_table *wait);
+int snd_seq_client_notify_subscription(int client, int port,
+				       struct snd_seq_port_subscribe *info, int evtype);
+
+int __snd_seq_deliver_single_event(struct snd_seq_client *dest,
+				   struct snd_seq_client_port *dest_port,
+				   struct snd_seq_event *event,
+				   int atomic, int hop);
+
+/* only for OSS sequencer */
+bool snd_seq_client_ioctl_lock(int clientid);
+void snd_seq_client_ioctl_unlock(int clientid);
+
+extern int seq_client_load[15];
+
+/* for internal use between kernel sequencer clients */
+struct snd_seq_client *snd_seq_kernel_client_get(int client);
+void snd_seq_kernel_client_put(struct snd_seq_client *cptr);
+
+static inline bool snd_seq_client_is_ump(struct snd_seq_client *c)
+{
+	return c->midi_version != SNDRV_SEQ_CLIENT_LEGACY_MIDI;
+}
+
+static inline bool snd_seq_client_is_midi2(struct snd_seq_client *c)
+{
+	return c->midi_version == SNDRV_SEQ_CLIENT_UMP_MIDI_2_0;
+}
+
+#endif
diff --git a/sound/core/seq/seq_compat.c b/sound/core/seq/seq_compat.c
new file mode 100644
index 0000000000..1e35bf086a
--- /dev/null
+++ b/sound/core/seq/seq_compat.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   32bit -> 64bit ioctl wrapper for sequencer API
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ */
+
+/* This file included from seq.c */
+
+#include <linux/compat.h>
+#include <linux/slab.h>
+
+struct snd_seq_port_info32 {
+	struct snd_seq_addr addr;	/* client/port numbers */
+	char name[64];			/* port name */
+
+	u32 capability;	/* port capability bits */
+	u32 type;		/* port type bits */
+	s32 midi_channels;		/* channels per MIDI port */
+	s32 midi_voices;		/* voices per MIDI port */
+	s32 synth_voices;		/* voices per SYNTH port */
+
+	s32 read_use;			/* R/O: subscribers for output (from this port) */
+	s32 write_use;			/* R/O: subscribers for input (to this port) */
+
+	u32 kernel;			/* reserved for kernel use (must be NULL) */
+	u32 flags;		/* misc. conditioning */
+	unsigned char time_queue;	/* queue # for timestamping */
+	char reserved[59];		/* for future use */
+};
+
+static int snd_seq_call_port_info_ioctl(struct snd_seq_client *client, unsigned int cmd,
+					struct snd_seq_port_info32 __user *data32)
+{
+	int err = -EFAULT;
+	struct snd_seq_port_info *data;
+
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	if (copy_from_user(data, data32, sizeof(*data32)) ||
+	    get_user(data->flags, &data32->flags) ||
+	    get_user(data->time_queue, &data32->time_queue))
+		goto error;
+	data->kernel = NULL;
+
+	err = snd_seq_kernel_client_ctl(client->number, cmd, data);
+	if (err < 0)
+		goto error;
+
+	if (copy_to_user(data32, data, sizeof(*data32)) ||
+	    put_user(data->flags, &data32->flags) ||
+	    put_user(data->time_queue, &data32->time_queue))
+		err = -EFAULT;
+
+ error:
+	kfree(data);
+	return err;
+}
+
+
+
+/*
+ */
+
+enum {
+	SNDRV_SEQ_IOCTL_CREATE_PORT32 = _IOWR('S', 0x20, struct snd_seq_port_info32),
+	SNDRV_SEQ_IOCTL_DELETE_PORT32 = _IOW ('S', 0x21, struct snd_seq_port_info32),
+	SNDRV_SEQ_IOCTL_GET_PORT_INFO32 = _IOWR('S', 0x22, struct snd_seq_port_info32),
+	SNDRV_SEQ_IOCTL_SET_PORT_INFO32 = _IOW ('S', 0x23, struct snd_seq_port_info32),
+	SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT32 = _IOWR('S', 0x52, struct snd_seq_port_info32),
+};
+
+static long snd_seq_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct snd_seq_client *client = file->private_data;
+	void __user *argp = compat_ptr(arg);
+
+	if (snd_BUG_ON(!client))
+		return -ENXIO;
+
+	switch (cmd) {
+	case SNDRV_SEQ_IOCTL_PVERSION:
+	case SNDRV_SEQ_IOCTL_USER_PVERSION:
+	case SNDRV_SEQ_IOCTL_CLIENT_ID:
+	case SNDRV_SEQ_IOCTL_SYSTEM_INFO:
+	case SNDRV_SEQ_IOCTL_GET_CLIENT_INFO:
+	case SNDRV_SEQ_IOCTL_SET_CLIENT_INFO:
+	case SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO:
+	case SNDRV_SEQ_IOCTL_SET_CLIENT_UMP_INFO:
+	case SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT:
+	case SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT:
+	case SNDRV_SEQ_IOCTL_CREATE_QUEUE:
+	case SNDRV_SEQ_IOCTL_DELETE_QUEUE:
+	case SNDRV_SEQ_IOCTL_GET_QUEUE_INFO:
+	case SNDRV_SEQ_IOCTL_SET_QUEUE_INFO:
+	case SNDRV_SEQ_IOCTL_GET_NAMED_QUEUE:
+	case SNDRV_SEQ_IOCTL_GET_QUEUE_STATUS:
+	case SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO:
+	case SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO:
+	case SNDRV_SEQ_IOCTL_GET_QUEUE_TIMER:
+	case SNDRV_SEQ_IOCTL_SET_QUEUE_TIMER:
+	case SNDRV_SEQ_IOCTL_GET_QUEUE_CLIENT:
+	case SNDRV_SEQ_IOCTL_SET_QUEUE_CLIENT:
+	case SNDRV_SEQ_IOCTL_GET_CLIENT_POOL:
+	case SNDRV_SEQ_IOCTL_SET_CLIENT_POOL:
+	case SNDRV_SEQ_IOCTL_REMOVE_EVENTS:
+	case SNDRV_SEQ_IOCTL_QUERY_SUBS:
+	case SNDRV_SEQ_IOCTL_GET_SUBSCRIPTION:
+	case SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT:
+	case SNDRV_SEQ_IOCTL_RUNNING_MODE:
+		return snd_seq_ioctl(file, cmd, arg);
+	case SNDRV_SEQ_IOCTL_CREATE_PORT32:
+		return snd_seq_call_port_info_ioctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, argp);
+	case SNDRV_SEQ_IOCTL_DELETE_PORT32:
+		return snd_seq_call_port_info_ioctl(client, SNDRV_SEQ_IOCTL_DELETE_PORT, argp);
+	case SNDRV_SEQ_IOCTL_GET_PORT_INFO32:
+		return snd_seq_call_port_info_ioctl(client, SNDRV_SEQ_IOCTL_GET_PORT_INFO, argp);
+	case SNDRV_SEQ_IOCTL_SET_PORT_INFO32:
+		return snd_seq_call_port_info_ioctl(client, SNDRV_SEQ_IOCTL_SET_PORT_INFO, argp);
+	case SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT32:
+		return snd_seq_call_port_info_ioctl(client, SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, argp);
+	}
+	return -ENOIOCTLCMD;
+}
diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c
new file mode 100644
index 0000000000..9308194b2d
--- /dev/null
+++ b/sound/core/seq/seq_dummy.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ALSA sequencer MIDI-through client
+ * Copyright (c) 1999-2000 by Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include "seq_clientmgr.h"
+#include <sound/initval.h>
+#include <sound/asoundef.h>
+
+/*
+
+  Sequencer MIDI-through client
+
+  This gives a simple midi-through client.  All the normal input events
+  are redirected to output port immediately.
+  The routing can be done via aconnect program in alsa-utils.
+
+  Each client has a static client number 14 (= SNDRV_SEQ_CLIENT_DUMMY).
+  If you want to auto-load this module, you may add the following alias
+  in your /etc/conf.modules file.
+
+	alias snd-seq-client-14  snd-seq-dummy
+
+  The module is loaded on demand for client 14, or /proc/asound/seq/
+  is accessed.  If you don't need this module to be loaded, alias
+  snd-seq-client-14 as "off".  This will help modprobe.
+
+  The number of ports to be created can be specified via the module
+  parameter "ports".  For example, to create four ports, add the
+  following option in a configuration file under /etc/modprobe.d/:
+
+	option snd-seq-dummy ports=4
+
+  The model option "duplex=1" enables duplex operation to the port.
+  In duplex mode, a pair of ports are created instead of single port,
+  and events are tunneled between pair-ports.  For example, input to
+  port A is sent to output port of another port B and vice versa.
+  In duplex mode, each port has DUPLEX capability.
+
+ */
+
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA sequencer MIDI-through client");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("snd-seq-client-" __stringify(SNDRV_SEQ_CLIENT_DUMMY));
+
+static int ports = 1;
+static bool duplex;
+
+module_param(ports, int, 0444);
+MODULE_PARM_DESC(ports, "number of ports to be created");
+module_param(duplex, bool, 0444);
+MODULE_PARM_DESC(duplex, "create DUPLEX ports");
+
+struct snd_seq_dummy_port {
+	int client;
+	int port;
+	int duplex;
+	int connect;
+};
+
+static int my_client = -1;
+
+/*
+ * event input callback - just redirect events to subscribers
+ */
+static int
+dummy_input(struct snd_seq_event *ev, int direct, void *private_data,
+	    int atomic, int hop)
+{
+	struct snd_seq_dummy_port *p;
+	struct snd_seq_event tmpev;
+
+	p = private_data;
+	if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
+	    ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
+		return 0; /* ignore system messages */
+	tmpev = *ev;
+	if (p->duplex)
+		tmpev.source.port = p->connect;
+	else
+		tmpev.source.port = p->port;
+	tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+	return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
+}
+
+/*
+ * free_private callback
+ */
+static void
+dummy_free(void *private_data)
+{
+	kfree(private_data);
+}
+
+/*
+ * create a port
+ */
+static struct snd_seq_dummy_port __init *
+create_port(int idx, int type)
+{
+	struct snd_seq_port_info pinfo;
+	struct snd_seq_port_callback pcb;
+	struct snd_seq_dummy_port *rec;
+
+	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
+	if (!rec)
+		return NULL;
+
+	rec->client = my_client;
+	rec->duplex = duplex;
+	rec->connect = 0;
+	memset(&pinfo, 0, sizeof(pinfo));
+	pinfo.addr.client = my_client;
+	if (duplex)
+		sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
+			(type ? 'B' : 'A'));
+	else
+		sprintf(pinfo.name, "Midi Through Port-%d", idx);
+	pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
+	pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+	if (duplex)
+		pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+	pinfo.direction = SNDRV_SEQ_PORT_DIR_BIDIRECTION;
+	pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
+		| SNDRV_SEQ_PORT_TYPE_SOFTWARE
+		| SNDRV_SEQ_PORT_TYPE_PORT;
+	memset(&pcb, 0, sizeof(pcb));
+	pcb.owner = THIS_MODULE;
+	pcb.event_input = dummy_input;
+	pcb.private_free = dummy_free;
+	pcb.private_data = rec;
+	pinfo.kernel = &pcb;
+	if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
+		kfree(rec);
+		return NULL;
+	}
+	rec->port = pinfo.addr.port;
+	return rec;
+}
+
+/*
+ * register client and create ports
+ */
+static int __init
+register_client(void)
+{
+	struct snd_seq_dummy_port *rec1, *rec2;
+	struct snd_seq_client *client;
+	int i;
+
+	if (ports < 1) {
+		pr_err("ALSA: seq_dummy: invalid number of ports %d\n", ports);
+		return -EINVAL;
+	}
+
+	/* create client */
+	my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY,
+						 "Midi Through");
+	if (my_client < 0)
+		return my_client;
+
+	/* don't convert events but just pass-through */
+	client = snd_seq_kernel_client_get(my_client);
+	if (!client)
+		return -EINVAL;
+	client->filter = SNDRV_SEQ_FILTER_NO_CONVERT;
+	snd_seq_kernel_client_put(client);
+
+	/* create ports */
+	for (i = 0; i < ports; i++) {
+		rec1 = create_port(i, 0);
+		if (rec1 == NULL) {
+			snd_seq_delete_kernel_client(my_client);
+			return -ENOMEM;
+		}
+		if (duplex) {
+			rec2 = create_port(i, 1);
+			if (rec2 == NULL) {
+				snd_seq_delete_kernel_client(my_client);
+				return -ENOMEM;
+			}
+			rec1->connect = rec2->port;
+			rec2->connect = rec1->port;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * delete client if exists
+ */
+static void __exit
+delete_client(void)
+{
+	if (my_client >= 0)
+		snd_seq_delete_kernel_client(my_client);
+}
+
+/*
+ *  Init part
+ */
+
+static int __init alsa_seq_dummy_init(void)
+{
+	return register_client();
+}
+
+static void __exit alsa_seq_dummy_exit(void)
+{
+	delete_client();
+}
+
+module_init(alsa_seq_dummy_init)
+module_exit(alsa_seq_dummy_exit)
diff --git a/sound/core/seq/seq_fifo.c b/sound/core/seq/seq_fifo.c
new file mode 100644
index 0000000000..f8e02e9870
--- /dev/null
+++ b/sound/core/seq/seq_fifo.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer FIFO
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+
+#include <sound/core.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+
+#include "seq_fifo.h"
+#include "seq_lock.h"
+
+
+/* FIFO */
+
+/* create new fifo */
+struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
+{
+	struct snd_seq_fifo *f;
+
+	f = kzalloc(sizeof(*f), GFP_KERNEL);
+	if (!f)
+		return NULL;
+
+	f->pool = snd_seq_pool_new(poolsize);
+	if (f->pool == NULL) {
+		kfree(f);
+		return NULL;
+	}
+	if (snd_seq_pool_init(f->pool) < 0) {
+		snd_seq_pool_delete(&f->pool);
+		kfree(f);
+		return NULL;
+	}
+
+	spin_lock_init(&f->lock);
+	snd_use_lock_init(&f->use_lock);
+	init_waitqueue_head(&f->input_sleep);
+	atomic_set(&f->overflow, 0);
+
+	f->head = NULL;
+	f->tail = NULL;
+	f->cells = 0;
+	
+	return f;
+}
+
+void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
+{
+	struct snd_seq_fifo *f;
+
+	if (snd_BUG_ON(!fifo))
+		return;
+	f = *fifo;
+	if (snd_BUG_ON(!f))
+		return;
+	*fifo = NULL;
+
+	if (f->pool)
+		snd_seq_pool_mark_closing(f->pool);
+
+	snd_seq_fifo_clear(f);
+
+	/* wake up clients if any */
+	if (waitqueue_active(&f->input_sleep))
+		wake_up(&f->input_sleep);
+
+	/* release resources...*/
+	/*....................*/
+
+	if (f->pool) {
+		snd_seq_pool_done(f->pool);
+		snd_seq_pool_delete(&f->pool);
+	}
+	
+	kfree(f);
+}
+
+static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
+
+/* clear queue */
+void snd_seq_fifo_clear(struct snd_seq_fifo *f)
+{
+	struct snd_seq_event_cell *cell;
+
+	/* clear overflow flag */
+	atomic_set(&f->overflow, 0);
+
+	snd_use_lock_sync(&f->use_lock);
+	spin_lock_irq(&f->lock);
+	/* drain the fifo */
+	while ((cell = fifo_cell_out(f)) != NULL) {
+		snd_seq_cell_free(cell);
+	}
+	spin_unlock_irq(&f->lock);
+}
+
+
+/* enqueue event to fifo */
+int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
+			  struct snd_seq_event *event)
+{
+	struct snd_seq_event_cell *cell;
+	unsigned long flags;
+	int err;
+
+	if (snd_BUG_ON(!f))
+		return -EINVAL;
+
+	snd_use_lock_use(&f->use_lock);
+	err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL, NULL); /* always non-blocking */
+	if (err < 0) {
+		if ((err == -ENOMEM) || (err == -EAGAIN))
+			atomic_inc(&f->overflow);
+		snd_use_lock_free(&f->use_lock);
+		return err;
+	}
+		
+	/* append new cells to fifo */
+	spin_lock_irqsave(&f->lock, flags);
+	if (f->tail != NULL)
+		f->tail->next = cell;
+	f->tail = cell;
+	if (f->head == NULL)
+		f->head = cell;
+	cell->next = NULL;
+	f->cells++;
+	spin_unlock_irqrestore(&f->lock, flags);
+
+	/* wakeup client */
+	if (waitqueue_active(&f->input_sleep))
+		wake_up(&f->input_sleep);
+
+	snd_use_lock_free(&f->use_lock);
+
+	return 0; /* success */
+
+}
+
+/* dequeue cell from fifo */
+static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
+{
+	struct snd_seq_event_cell *cell;
+
+	cell = f->head;
+	if (cell) {
+		f->head = cell->next;
+
+		/* reset tail if this was the last element */
+		if (f->tail == cell)
+			f->tail = NULL;
+
+		cell->next = NULL;
+		f->cells--;
+	}
+
+	return cell;
+}
+
+/* dequeue cell from fifo and copy on user space */
+int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
+			  struct snd_seq_event_cell **cellp, int nonblock)
+{
+	struct snd_seq_event_cell *cell;
+	unsigned long flags;
+	wait_queue_entry_t wait;
+
+	if (snd_BUG_ON(!f))
+		return -EINVAL;
+
+	*cellp = NULL;
+	init_waitqueue_entry(&wait, current);
+	spin_lock_irqsave(&f->lock, flags);
+	while ((cell = fifo_cell_out(f)) == NULL) {
+		if (nonblock) {
+			/* non-blocking - return immediately */
+			spin_unlock_irqrestore(&f->lock, flags);
+			return -EAGAIN;
+		}
+		set_current_state(TASK_INTERRUPTIBLE);
+		add_wait_queue(&f->input_sleep, &wait);
+		spin_unlock_irqrestore(&f->lock, flags);
+		schedule();
+		spin_lock_irqsave(&f->lock, flags);
+		remove_wait_queue(&f->input_sleep, &wait);
+		if (signal_pending(current)) {
+			spin_unlock_irqrestore(&f->lock, flags);
+			return -ERESTARTSYS;
+		}
+	}
+	spin_unlock_irqrestore(&f->lock, flags);
+	*cellp = cell;
+
+	return 0;
+}
+
+
+void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
+			       struct snd_seq_event_cell *cell)
+{
+	unsigned long flags;
+
+	if (cell) {
+		spin_lock_irqsave(&f->lock, flags);
+		cell->next = f->head;
+		f->head = cell;
+		if (!f->tail)
+			f->tail = cell;
+		f->cells++;
+		spin_unlock_irqrestore(&f->lock, flags);
+	}
+}
+
+
+/* polling; return non-zero if queue is available */
+int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
+			   poll_table *wait)
+{
+	poll_wait(file, &f->input_sleep, wait);
+	return (f->cells > 0);
+}
+
+/* change the size of pool; all old events are removed */
+int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
+{
+	struct snd_seq_pool *newpool, *oldpool;
+	struct snd_seq_event_cell *cell, *next, *oldhead;
+
+	if (snd_BUG_ON(!f || !f->pool))
+		return -EINVAL;
+
+	/* allocate new pool */
+	newpool = snd_seq_pool_new(poolsize);
+	if (newpool == NULL)
+		return -ENOMEM;
+	if (snd_seq_pool_init(newpool) < 0) {
+		snd_seq_pool_delete(&newpool);
+		return -ENOMEM;
+	}
+
+	spin_lock_irq(&f->lock);
+	/* remember old pool */
+	oldpool = f->pool;
+	oldhead = f->head;
+	/* exchange pools */
+	f->pool = newpool;
+	f->head = NULL;
+	f->tail = NULL;
+	f->cells = 0;
+	/* NOTE: overflow flag is not cleared */
+	spin_unlock_irq(&f->lock);
+
+	/* close the old pool and wait until all users are gone */
+	snd_seq_pool_mark_closing(oldpool);
+	snd_use_lock_sync(&f->use_lock);
+
+	/* release cells in old pool */
+	for (cell = oldhead; cell; cell = next) {
+		next = cell->next;
+		snd_seq_cell_free(cell);
+	}
+	snd_seq_pool_delete(&oldpool);
+
+	return 0;
+}
+
+/* get the number of unused cells safely */
+int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f)
+{
+	unsigned long flags;
+	int cells;
+
+	if (!f)
+		return 0;
+
+	snd_use_lock_use(&f->use_lock);
+	spin_lock_irqsave(&f->lock, flags);
+	cells = snd_seq_unused_cells(f->pool);
+	spin_unlock_irqrestore(&f->lock, flags);
+	snd_use_lock_free(&f->use_lock);
+	return cells;
+}
diff --git a/sound/core/seq/seq_fifo.h b/sound/core/seq/seq_fifo.h
new file mode 100644
index 0000000000..b56a7b897c
--- /dev/null
+++ b/sound/core/seq/seq_fifo.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer FIFO
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_FIFO_H
+#define __SND_SEQ_FIFO_H
+
+#include "seq_memory.h"
+#include "seq_lock.h"
+
+
+/* === FIFO === */
+
+struct snd_seq_fifo {
+	struct snd_seq_pool *pool;		/* FIFO pool */
+	struct snd_seq_event_cell *head;    	/* pointer to head of fifo */
+	struct snd_seq_event_cell *tail;    	/* pointer to tail of fifo */
+	int cells;
+	spinlock_t lock;
+	snd_use_lock_t use_lock;
+	wait_queue_head_t input_sleep;
+	atomic_t overflow;
+
+};
+
+/* create new fifo (constructor) */
+struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
+
+/* delete fifo (destructor) */
+void snd_seq_fifo_delete(struct snd_seq_fifo **f);
+
+
+/* enqueue event to fifo */
+int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);
+
+/* lock fifo from release */
+#define snd_seq_fifo_lock(fifo)		snd_use_lock_use(&(fifo)->use_lock)
+#define snd_seq_fifo_unlock(fifo)	snd_use_lock_free(&(fifo)->use_lock)
+
+/* get a cell from fifo - fifo should be locked */
+int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
+
+/* free dequeued cell - fifo should be locked */
+void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
+
+/* clean up queue */
+void snd_seq_fifo_clear(struct snd_seq_fifo *f);
+
+/* polling */
+int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
+
+/* resize pool in fifo */
+int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
+
+/* get the number of unused cells safely */
+int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f);
+
+#endif
diff --git a/sound/core/seq/seq_info.c b/sound/core/seq/seq_info.c
new file mode 100644
index 0000000000..3e9fce7bea
--- /dev/null
+++ b/sound/core/seq/seq_info.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer /proc interface
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <sound/core.h>
+
+#include "seq_info.h"
+#include "seq_clientmgr.h"
+#include "seq_timer.h"
+
+static struct snd_info_entry *queues_entry;
+static struct snd_info_entry *clients_entry;
+static struct snd_info_entry *timer_entry;
+
+
+static struct snd_info_entry * __init
+create_info_entry(char *name, void (*read)(struct snd_info_entry *,
+					   struct snd_info_buffer *))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, name, snd_seq_root);
+	if (entry == NULL)
+		return NULL;
+	entry->content = SNDRV_INFO_CONTENT_TEXT;
+	entry->c.text.read = read;
+	if (snd_info_register(entry) < 0) {
+		snd_info_free_entry(entry);
+		return NULL;
+	}
+	return entry;
+}
+
+void snd_seq_info_done(void)
+{
+	snd_info_free_entry(queues_entry);
+	snd_info_free_entry(clients_entry);
+	snd_info_free_entry(timer_entry);
+}
+
+/* create all our /proc entries */
+int __init snd_seq_info_init(void)
+{
+	queues_entry = create_info_entry("queues",
+					 snd_seq_info_queues_read);
+	clients_entry = create_info_entry("clients",
+					  snd_seq_info_clients_read);
+	timer_entry = create_info_entry("timer", snd_seq_info_timer_read);
+	if (!queues_entry || !clients_entry || !timer_entry)
+		goto error;
+	return 0;
+
+ error:
+	snd_seq_info_done();
+	return -ENOMEM;
+}
diff --git a/sound/core/seq/seq_info.h b/sound/core/seq/seq_info.h
new file mode 100644
index 0000000000..576cf05221
--- /dev/null
+++ b/sound/core/seq/seq_info.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer /proc info
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_INFO_H
+#define __SND_SEQ_INFO_H
+
+#include <sound/info.h>
+#include <sound/seq_kernel.h>
+
+void snd_seq_info_clients_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer);
+void snd_seq_info_timer_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer);
+void snd_seq_info_queues_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer);
+
+
+#ifdef CONFIG_SND_PROC_FS
+int snd_seq_info_init(void);
+void snd_seq_info_done(void);
+#else
+static inline int snd_seq_info_init(void) { return 0; }
+static inline void snd_seq_info_done(void) {}
+#endif
+
+#endif
diff --git a/sound/core/seq/seq_lock.c b/sound/core/seq/seq_lock.c
new file mode 100644
index 0000000000..48b4ffb4b7
--- /dev/null
+++ b/sound/core/seq/seq_lock.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Do sleep inside a spin-lock
+ *  Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/export.h>
+#include <sound/core.h>
+#include "seq_lock.h"
+
+/* wait until all locks are released */
+void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
+{
+	int warn_count = 5 * HZ;
+
+	if (atomic_read(lockp) < 0) {
+		pr_warn("ALSA: seq_lock: lock trouble [counter = %d] in %s:%d\n", atomic_read(lockp), file, line);
+		return;
+	}
+	while (atomic_read(lockp) > 0) {
+		if (warn_count-- == 0)
+			pr_warn("ALSA: seq_lock: waiting [%d left] in %s:%d\n", atomic_read(lockp), file, line);
+		schedule_timeout_uninterruptible(1);
+	}
+}
+EXPORT_SYMBOL(snd_use_lock_sync_helper);
diff --git a/sound/core/seq/seq_lock.h b/sound/core/seq/seq_lock.h
new file mode 100644
index 0000000000..a973860ebc
--- /dev/null
+++ b/sound/core/seq/seq_lock.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __SND_SEQ_LOCK_H
+#define __SND_SEQ_LOCK_H
+
+#include <linux/sched.h>
+
+typedef atomic_t snd_use_lock_t;
+
+/* initialize lock */
+#define snd_use_lock_init(lockp) atomic_set(lockp, 0)
+
+/* increment lock */
+#define snd_use_lock_use(lockp) atomic_inc(lockp)
+
+/* release lock */
+#define snd_use_lock_free(lockp) atomic_dec(lockp)
+
+/* wait until all locks are released */
+void snd_use_lock_sync_helper(snd_use_lock_t *lock, const char *file, int line);
+#define snd_use_lock_sync(lockp) snd_use_lock_sync_helper(lockp, __BASE_FILE__, __LINE__)
+
+#endif /* __SND_SEQ_LOCK_H */
diff --git a/sound/core/seq/seq_memory.c b/sound/core/seq/seq_memory.c
new file mode 100644
index 0000000000..b603bb93f8
--- /dev/null
+++ b/sound/core/seq/seq_memory.c
@@ -0,0 +1,570 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  ALSA sequencer Memory Manager
+ *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *                        Jaroslav Kysela <perex@perex.cz>
+ *                2000 by Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/mm.h>
+#include <sound/core.h>
+
+#include <sound/seq_kernel.h>
+#include "seq_memory.h"
+#include "seq_queue.h"
+#include "seq_info.h"
+#include "seq_lock.h"
+
+static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
+{
+	return pool->total_elements - atomic_read(&pool->counter);
+}
+
+static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
+{
+	return snd_seq_pool_available(pool) >= pool->room;
+}
+
+/*
+ * Variable length event:
+ * The event like sysex uses variable length type.
+ * The external data may be stored in three different formats.
+ * 1) kernel space
+ *    This is the normal case.
+ *      ext.data.len = length
+ *      ext.data.ptr = buffer pointer
+ * 2) user space
+ *    When an event is generated via read(), the external data is
+ *    kept in user space until expanded.
+ *      ext.data.len = length | SNDRV_SEQ_EXT_USRPTR
+ *      ext.data.ptr = userspace pointer
+ * 3) chained cells
+ *    When the variable length event is enqueued (in prioq or fifo),
+ *    the external data is decomposed to several cells.
+ *      ext.data.len = length | SNDRV_SEQ_EXT_CHAINED
+ *      ext.data.ptr = the additiona cell head
+ *         -> cell.next -> cell.next -> ..
+ */
+
+/*
+ * exported:
+ * call dump function to expand external data.
+ */
+
+static int get_var_len(const struct snd_seq_event *event)
+{
+	if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
+		return -EINVAL;
+
+	return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
+}
+
+static int dump_var_event(const struct snd_seq_event *event,
+			  snd_seq_dump_func_t func, void *private_data,
+			  int offset, int maxlen)
+{
+	int len, err;
+	struct snd_seq_event_cell *cell;
+
+	len = get_var_len(event);
+	if (len <= 0)
+		return len;
+	if (len <= offset)
+		return 0;
+	if (maxlen && len > offset + maxlen)
+		len = offset + maxlen;
+
+	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
+		char buf[32];
+		char __user *curptr = (char __force __user *)event->data.ext.ptr;
+		curptr += offset;
+		len -= offset;
+		while (len > 0) {
+			int size = sizeof(buf);
+			if (len < size)
+				size = len;
+			if (copy_from_user(buf, curptr, size))
+				return -EFAULT;
+			err = func(private_data, buf, size);
+			if (err < 0)
+				return err;
+			curptr += size;
+			len -= size;
+		}
+		return 0;
+	}
+	if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
+		return func(private_data, event->data.ext.ptr + offset,
+			    len - offset);
+
+	cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
+	for (; len > 0 && cell; cell = cell->next) {
+		int size = sizeof(struct snd_seq_event);
+		char *curptr = (char *)&cell->event;
+
+		if (offset >= size) {
+			offset -= size;
+			len -= size;
+			continue;
+		}
+		if (len < size)
+			size = len;
+		err = func(private_data, curptr + offset, size - offset);
+		if (err < 0)
+			return err;
+		offset = 0;
+		len -= size;
+	}
+	return 0;
+}
+
+int snd_seq_dump_var_event(const struct snd_seq_event *event,
+			   snd_seq_dump_func_t func, void *private_data)
+{
+	return dump_var_event(event, func, private_data, 0, 0);
+}
+EXPORT_SYMBOL(snd_seq_dump_var_event);
+
+
+/*
+ * exported:
+ * expand the variable length event to linear buffer space.
+ */
+
+static int seq_copy_in_kernel(void *ptr, void *src, int size)
+{
+	char **bufptr = ptr;
+
+	memcpy(*bufptr, src, size);
+	*bufptr += size;
+	return 0;
+}
+
+static int seq_copy_in_user(void *ptr, void *src, int size)
+{
+	char __user **bufptr = ptr;
+
+	if (copy_to_user(*bufptr, src, size))
+		return -EFAULT;
+	*bufptr += size;
+	return 0;
+}
+
+static int expand_var_event(const struct snd_seq_event *event,
+			    int offset, int size, char *buf, bool in_kernel)
+{
+	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
+		if (! in_kernel)
+			return -EINVAL;
+		if (copy_from_user(buf,
+				   (char __force __user *)event->data.ext.ptr + offset,
+				   size))
+			return -EFAULT;
+		return 0;
+	}
+	return dump_var_event(event,
+			     in_kernel ? seq_copy_in_kernel : seq_copy_in_user,
+			     &buf, offset, size);
+}
+
+int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
+			     int in_kernel, int size_aligned)
+{
+	int len, newlen, err;
+
+	len = get_var_len(event);
+	if (len < 0)
+		return len;
+	newlen = len;
+	if (size_aligned > 0)
+		newlen = roundup(len, size_aligned);
+	if (count < newlen)
+		return -EAGAIN;
+	err = expand_var_event(event, 0, len, buf, in_kernel);
+	if (err < 0)
+		return err;
+	if (len != newlen) {
+		if (in_kernel)
+			memset(buf + len, 0, newlen - len);
+		else if (clear_user((__force void __user *)buf + len,
+				    newlen - len))
+			return -EFAULT;
+	}
+	return newlen;
+}
+EXPORT_SYMBOL(snd_seq_expand_var_event);
+
+int snd_seq_expand_var_event_at(const struct snd_seq_event *event, int count,
+				char *buf, int offset)
+{
+	int len, err;
+
+	len = get_var_len(event);
+	if (len < 0)
+		return len;
+	if (len <= offset)
+		return 0;
+	len -= offset;
+	if (len > count)
+		len = count;
+	err = expand_var_event(event, offset, count, buf, true);
+	if (err < 0)
+		return err;
+	return len;
+}
+EXPORT_SYMBOL_GPL(snd_seq_expand_var_event_at);
+
+/*
+ * release this cell, free extended data if available
+ */
+
+static inline void free_cell(struct snd_seq_pool *pool,
+			     struct snd_seq_event_cell *cell)
+{
+	cell->next = pool->free;
+	pool->free = cell;
+	atomic_dec(&pool->counter);
+}
+
+void snd_seq_cell_free(struct snd_seq_event_cell * cell)
+{
+	unsigned long flags;
+	struct snd_seq_pool *pool;
+
+	if (snd_BUG_ON(!cell))
+		return;
+	pool = cell->pool;
+	if (snd_BUG_ON(!pool))
+		return;
+
+	spin_lock_irqsave(&pool->lock, flags);
+	free_cell(pool, cell);
+	if (snd_seq_ev_is_variable(&cell->event)) {
+		if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
+			struct snd_seq_event_cell *curp, *nextptr;
+			curp = cell->event.data.ext.ptr;
+			for (; curp; curp = nextptr) {
+				nextptr = curp->next;
+				curp->next = pool->free;
+				free_cell(pool, curp);
+			}
+		}
+	}
+	if (waitqueue_active(&pool->output_sleep)) {
+		/* has enough space now? */
+		if (snd_seq_output_ok(pool))
+			wake_up(&pool->output_sleep);
+	}
+	spin_unlock_irqrestore(&pool->lock, flags);
+}
+
+
+/*
+ * allocate an event cell.
+ */
+static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
+			      struct snd_seq_event_cell **cellp,
+			      int nonblock, struct file *file,
+			      struct mutex *mutexp)
+{
+	struct snd_seq_event_cell *cell;
+	unsigned long flags;
+	int err = -EAGAIN;
+	wait_queue_entry_t wait;
+
+	if (pool == NULL)
+		return -EINVAL;
+
+	*cellp = NULL;
+
+	init_waitqueue_entry(&wait, current);
+	spin_lock_irqsave(&pool->lock, flags);
+	if (pool->ptr == NULL) {	/* not initialized */
+		pr_debug("ALSA: seq: pool is not initialized\n");
+		err = -EINVAL;
+		goto __error;
+	}
+	while (pool->free == NULL && ! nonblock && ! pool->closing) {
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		add_wait_queue(&pool->output_sleep, &wait);
+		spin_unlock_irqrestore(&pool->lock, flags);
+		if (mutexp)
+			mutex_unlock(mutexp);
+		schedule();
+		if (mutexp)
+			mutex_lock(mutexp);
+		spin_lock_irqsave(&pool->lock, flags);
+		remove_wait_queue(&pool->output_sleep, &wait);
+		/* interrupted? */
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			goto __error;
+		}
+	}
+	if (pool->closing) { /* closing.. */
+		err = -ENOMEM;
+		goto __error;
+	}
+
+	cell = pool->free;
+	if (cell) {
+		int used;
+		pool->free = cell->next;
+		atomic_inc(&pool->counter);
+		used = atomic_read(&pool->counter);
+		if (pool->max_used < used)
+			pool->max_used = used;
+		pool->event_alloc_success++;
+		/* clear cell pointers */
+		cell->next = NULL;
+		err = 0;
+	} else
+		pool->event_alloc_failures++;
+	*cellp = cell;
+
+__error:
+	spin_unlock_irqrestore(&pool->lock, flags);
+	return err;
+}
+
+
+/*
+ * duplicate the event to a cell.
+ * if the event has external data, the data is decomposed to additional
+ * cells.
+ */
+int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
+		      struct snd_seq_event_cell **cellp, int nonblock,
+		      struct file *file, struct mutex *mutexp)
+{
+	int ncells, err;
+	unsigned int extlen;
+	struct snd_seq_event_cell *cell;
+	int size;
+
+	*cellp = NULL;
+
+	ncells = 0;
+	extlen = 0;
+	if (snd_seq_ev_is_variable(event)) {
+		extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
+		ncells = DIV_ROUND_UP(extlen, sizeof(struct snd_seq_event));
+	}
+	if (ncells >= pool->total_elements)
+		return -ENOMEM;
+
+	err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
+	if (err < 0)
+		return err;
+
+	/* copy the event */
+	size = snd_seq_event_packet_size(event);
+	memcpy(&cell->ump, event, size);
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+	if (size < sizeof(cell->event))
+		cell->ump.raw.extra = 0;
+#endif
+
+	/* decompose */
+	if (snd_seq_ev_is_variable(event)) {
+		int len = extlen;
+		int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
+		int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
+		struct snd_seq_event_cell *src, *tmp, *tail;
+		char *buf;
+
+		cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
+		cell->event.data.ext.ptr = NULL;
+
+		src = (struct snd_seq_event_cell *)event->data.ext.ptr;
+		buf = (char *)event->data.ext.ptr;
+		tail = NULL;
+
+		while (ncells-- > 0) {
+			size = sizeof(struct snd_seq_event);
+			if (len < size)
+				size = len;
+			err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
+						 mutexp);
+			if (err < 0)
+				goto __error;
+			if (cell->event.data.ext.ptr == NULL)
+				cell->event.data.ext.ptr = tmp;
+			if (tail)
+				tail->next = tmp;
+			tail = tmp;
+			/* copy chunk */
+			if (is_chained && src) {
+				tmp->event = src->event;
+				src = src->next;
+			} else if (is_usrptr) {
+				if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
+					err = -EFAULT;
+					goto __error;
+				}
+			} else {
+				memcpy(&tmp->event, buf, size);
+			}
+			buf += size;
+			len -= size;
+		}
+	}
+
+	*cellp = cell;
+	return 0;
+
+__error:
+	snd_seq_cell_free(cell);
+	return err;
+}
+  
+
+/* poll wait */
+int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
+			   poll_table *wait)
+{
+	poll_wait(file, &pool->output_sleep, wait);
+	return snd_seq_output_ok(pool);
+}
+
+
+/* allocate room specified number of events */
+int snd_seq_pool_init(struct snd_seq_pool *pool)
+{
+	int cell;
+	struct snd_seq_event_cell *cellptr;
+
+	if (snd_BUG_ON(!pool))
+		return -EINVAL;
+
+	cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
+				 GFP_KERNEL);
+	if (!cellptr)
+		return -ENOMEM;
+
+	/* add new cells to the free cell list */
+	spin_lock_irq(&pool->lock);
+	if (pool->ptr) {
+		spin_unlock_irq(&pool->lock);
+		kvfree(cellptr);
+		return 0;
+	}
+
+	pool->ptr = cellptr;
+	pool->free = NULL;
+
+	for (cell = 0; cell < pool->size; cell++) {
+		cellptr = pool->ptr + cell;
+		cellptr->pool = pool;
+		cellptr->next = pool->free;
+		pool->free = cellptr;
+	}
+	pool->room = (pool->size + 1) / 2;
+
+	/* init statistics */
+	pool->max_used = 0;
+	pool->total_elements = pool->size;
+	spin_unlock_irq(&pool->lock);
+	return 0;
+}
+
+/* refuse the further insertion to the pool */
+void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!pool))
+		return;
+	spin_lock_irqsave(&pool->lock, flags);
+	pool->closing = 1;
+	spin_unlock_irqrestore(&pool->lock, flags);
+}
+
+/* remove events */
+int snd_seq_pool_done(struct snd_seq_pool *pool)
+{
+	struct snd_seq_event_cell *ptr;
+
+	if (snd_BUG_ON(!pool))
+		return -EINVAL;
+
+	/* wait for closing all threads */
+	if (waitqueue_active(&pool->output_sleep))
+		wake_up(&pool->output_sleep);
+
+	while (atomic_read(&pool->counter) > 0)
+		schedule_timeout_uninterruptible(1);
+	
+	/* release all resources */
+	spin_lock_irq(&pool->lock);
+	ptr = pool->ptr;
+	pool->ptr = NULL;
+	pool->free = NULL;
+	pool->total_elements = 0;
+	spin_unlock_irq(&pool->lock);
+
+	kvfree(ptr);
+
+	spin_lock_irq(&pool->lock);
+	pool->closing = 0;
+	spin_unlock_irq(&pool->lock);
+
+	return 0;
+}
+
+
+/* init new memory pool */
+struct snd_seq_pool *snd_seq_pool_new(int poolsize)
+{
+	struct snd_seq_pool *pool;
+
+	/* create pool block */
+	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+	if (!pool)
+		return NULL;
+	spin_lock_init(&pool->lock);
+	pool->ptr = NULL;
+	pool->free = NULL;
+	pool->total_elements = 0;
+	atomic_set(&pool->counter, 0);
+	pool->closing = 0;
+	init_waitqueue_head(&pool->output_sleep);
+	
+	pool->size = poolsize;
+
+	/* init statistics */
+	pool->max_used = 0;
+	return pool;
+}
+
+/* remove memory pool */
+int snd_seq_pool_delete(struct snd_seq_pool **ppool)
+{
+	struct snd_seq_pool *pool = *ppool;
+
+	*ppool = NULL;
+	if (pool == NULL)
+		return 0;
+	snd_seq_pool_mark_closing(pool);
+	snd_seq_pool_done(pool);
+	kfree(pool);
+	return 0;
+}
+
+/* exported to seq_clientmgr.c */
+void snd_seq_info_pool(struct snd_info_buffer *buffer,
+		       struct snd_seq_pool *pool, char *space)
+{
+	if (pool == NULL)
+		return;
+	snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
+	snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
+	snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
+	snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
+	snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
+}
diff --git a/sound/core/seq/seq_memory.h b/sound/core/seq/seq_memory.h
new file mode 100644
index 0000000000..7f7a2c0b18
--- /dev/null
+++ b/sound/core/seq/seq_memory.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  ALSA sequencer Memory Manager
+ *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_MEMORYMGR_H
+#define __SND_SEQ_MEMORYMGR_H
+
+#include <sound/seq_kernel.h>
+#include <linux/poll.h>
+
+struct snd_info_buffer;
+
+/* aliasing for legacy and UMP event packet handling */
+union __snd_seq_event {
+	struct snd_seq_event legacy;
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+	struct snd_seq_ump_event ump;
+#endif
+	struct {
+		struct snd_seq_event event;
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+		u32 extra;
+#endif
+	} __packed raw;
+};
+
+/* container for sequencer event (internal use) */
+struct snd_seq_event_cell {
+	union {
+		struct snd_seq_event event;
+		union __snd_seq_event ump;
+	};
+	struct snd_seq_pool *pool;				/* used pool */
+	struct snd_seq_event_cell *next;	/* next cell */
+};
+
+/* design note: the pool is a contiguous block of memory, if we dynamicly
+   want to add additional cells to the pool be better store this in another
+   pool as we need to know the base address of the pool when releasing
+   memory. */
+
+struct snd_seq_pool {
+	struct snd_seq_event_cell *ptr;	/* pointer to first event chunk */
+	struct snd_seq_event_cell *free;	/* pointer to the head of the free list */
+
+	int total_elements;	/* pool size actually allocated */
+	atomic_t counter;	/* cells free */
+
+	int size;		/* pool size to be allocated */
+	int room;		/* watermark for sleep/wakeup */
+
+	int closing;
+
+	/* statistics */
+	int max_used;
+	int event_alloc_nopool;
+	int event_alloc_failures;
+	int event_alloc_success;
+
+	/* Write locking */
+	wait_queue_head_t output_sleep;
+
+	/* Pool lock */
+	spinlock_t lock;
+};
+
+void snd_seq_cell_free(struct snd_seq_event_cell *cell);
+
+int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
+		      struct snd_seq_event_cell **cellp, int nonblock,
+		      struct file *file, struct mutex *mutexp);
+
+/* return number of unused (free) cells */
+static inline int snd_seq_unused_cells(struct snd_seq_pool *pool)
+{
+	return pool ? pool->total_elements - atomic_read(&pool->counter) : 0;
+}
+
+/* return total number of allocated cells */
+static inline int snd_seq_total_cells(struct snd_seq_pool *pool)
+{
+	return pool ? pool->total_elements : 0;
+}
+
+/* init pool - allocate events */
+int snd_seq_pool_init(struct snd_seq_pool *pool);
+
+/* done pool - free events */
+void snd_seq_pool_mark_closing(struct snd_seq_pool *pool);
+int snd_seq_pool_done(struct snd_seq_pool *pool);
+
+/* create pool */
+struct snd_seq_pool *snd_seq_pool_new(int poolsize);
+
+/* remove pool */
+int snd_seq_pool_delete(struct snd_seq_pool **pool);
+
+/* polling */
+int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file, poll_table *wait);
+
+void snd_seq_info_pool(struct snd_info_buffer *buffer,
+		       struct snd_seq_pool *pool, char *space);
+
+#endif
diff --git a/sound/core/seq/seq_midi.c b/sound/core/seq/seq_midi.c
new file mode 100644
index 0000000000..18320a248a
--- /dev/null
+++ b/sound/core/seq/seq_midi.c
@@ -0,0 +1,463 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Generic MIDI synth driver for ALSA sequencer
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *                         Jaroslav Kysela <perex@perex.cz>
+ */
+ 
+/* 
+Possible options for midisynth module:
+	- automatic opening of midi ports on first received event or subscription
+	  (close will be performed when client leaves)
+*/
+
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <sound/core.h>
+#include <sound/rawmidi.h>
+#include <sound/seq_kernel.h>
+#include <sound/seq_device.h>
+#include <sound/seq_midi_event.h>
+#include <sound/initval.h>
+
+MODULE_AUTHOR("Frank van de Pol <fvdpol@coil.demon.nl>, Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI synth.");
+MODULE_LICENSE("GPL");
+static int output_buffer_size = PAGE_SIZE;
+module_param(output_buffer_size, int, 0644);
+MODULE_PARM_DESC(output_buffer_size, "Output buffer size in bytes.");
+static int input_buffer_size = PAGE_SIZE;
+module_param(input_buffer_size, int, 0644);
+MODULE_PARM_DESC(input_buffer_size, "Input buffer size in bytes.");
+
+/* data for this midi synth driver */
+struct seq_midisynth {
+	struct snd_card *card;
+	struct snd_rawmidi *rmidi;
+	int device;
+	int subdevice;
+	struct snd_rawmidi_file input_rfile;
+	struct snd_rawmidi_file output_rfile;
+	int seq_client;
+	int seq_port;
+	struct snd_midi_event *parser;
+};
+
+struct seq_midisynth_client {
+	int seq_client;
+	int num_ports;
+	int ports_per_device[SNDRV_RAWMIDI_DEVICES];
+ 	struct seq_midisynth *ports[SNDRV_RAWMIDI_DEVICES];
+};
+
+static struct seq_midisynth_client *synths[SNDRV_CARDS];
+static DEFINE_MUTEX(register_mutex);
+
+/* handle rawmidi input event (MIDI v1.0 stream) */
+static void snd_midi_input_event(struct snd_rawmidi_substream *substream)
+{
+	struct snd_rawmidi_runtime *runtime;
+	struct seq_midisynth *msynth;
+	struct snd_seq_event ev;
+	char buf[16], *pbuf;
+	long res;
+
+	if (substream == NULL)
+		return;
+	runtime = substream->runtime;
+	msynth = runtime->private_data;
+	if (msynth == NULL)
+		return;
+	memset(&ev, 0, sizeof(ev));
+	while (runtime->avail > 0) {
+		res = snd_rawmidi_kernel_read(substream, buf, sizeof(buf));
+		if (res <= 0)
+			continue;
+		if (msynth->parser == NULL)
+			continue;
+		pbuf = buf;
+		while (res-- > 0) {
+			if (!snd_midi_event_encode_byte(msynth->parser,
+							*pbuf++, &ev))
+				continue;
+			ev.source.port = msynth->seq_port;
+			ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+			snd_seq_kernel_client_dispatch(msynth->seq_client, &ev, 1, 0);
+			/* clear event and reset header */
+			memset(&ev, 0, sizeof(ev));
+		}
+	}
+}
+
+static int dump_midi(struct snd_rawmidi_substream *substream, const char *buf, int count)
+{
+	struct snd_rawmidi_runtime *runtime;
+	int tmp;
+
+	if (snd_BUG_ON(!substream || !buf))
+		return -EINVAL;
+	runtime = substream->runtime;
+	tmp = runtime->avail;
+	if (tmp < count) {
+		if (printk_ratelimit())
+			pr_err("ALSA: seq_midi: MIDI output buffer overrun\n");
+		return -ENOMEM;
+	}
+	if (snd_rawmidi_kernel_write(substream, buf, count) < count)
+		return -EINVAL;
+	return 0;
+}
+
+static int event_process_midi(struct snd_seq_event *ev, int direct,
+			      void *private_data, int atomic, int hop)
+{
+	struct seq_midisynth *msynth = private_data;
+	unsigned char msg[10];	/* buffer for constructing midi messages */
+	struct snd_rawmidi_substream *substream;
+	int len;
+
+	if (snd_BUG_ON(!msynth))
+		return -EINVAL;
+	substream = msynth->output_rfile.output;
+	if (substream == NULL)
+		return -ENODEV;
+	if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {	/* special case, to save space */
+		if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) {
+			/* invalid event */
+			pr_debug("ALSA: seq_midi: invalid sysex event flags = 0x%x\n", ev->flags);
+			return 0;
+		}
+		snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
+		snd_midi_event_reset_decode(msynth->parser);
+	} else {
+		if (msynth->parser == NULL)
+			return -EIO;
+		len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
+		if (len < 0)
+			return 0;
+		if (dump_midi(substream, msg, len) < 0)
+			snd_midi_event_reset_decode(msynth->parser);
+	}
+	return 0;
+}
+
+
+static int snd_seq_midisynth_new(struct seq_midisynth *msynth,
+				 struct snd_card *card,
+				 int device,
+				 int subdevice)
+{
+	if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0)
+		return -ENOMEM;
+	msynth->card = card;
+	msynth->device = device;
+	msynth->subdevice = subdevice;
+	return 0;
+}
+
+/* open associated midi device for input */
+static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info)
+{
+	int err;
+	struct seq_midisynth *msynth = private_data;
+	struct snd_rawmidi_runtime *runtime;
+	struct snd_rawmidi_params params;
+
+	/* open midi port */
+	err = snd_rawmidi_kernel_open(msynth->rmidi, msynth->subdevice,
+				      SNDRV_RAWMIDI_LFLG_INPUT,
+				      &msynth->input_rfile);
+	if (err < 0) {
+		pr_debug("ALSA: seq_midi: midi input open failed!!!\n");
+		return err;
+	}
+	runtime = msynth->input_rfile.input->runtime;
+	memset(&params, 0, sizeof(params));
+	params.avail_min = 1;
+	params.buffer_size = input_buffer_size;
+	err = snd_rawmidi_input_params(msynth->input_rfile.input, &params);
+	if (err < 0) {
+		snd_rawmidi_kernel_release(&msynth->input_rfile);
+		return err;
+	}
+	snd_midi_event_reset_encode(msynth->parser);
+	runtime->event = snd_midi_input_event;
+	runtime->private_data = msynth;
+	snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0);
+	return 0;
+}
+
+/* close associated midi device for input */
+static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info)
+{
+	int err;
+	struct seq_midisynth *msynth = private_data;
+
+	if (snd_BUG_ON(!msynth->input_rfile.input))
+		return -EINVAL;
+	err = snd_rawmidi_kernel_release(&msynth->input_rfile);
+	return err;
+}
+
+/* open associated midi device for output */
+static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info)
+{
+	int err;
+	struct seq_midisynth *msynth = private_data;
+	struct snd_rawmidi_params params;
+
+	/* open midi port */
+	err = snd_rawmidi_kernel_open(msynth->rmidi, msynth->subdevice,
+				      SNDRV_RAWMIDI_LFLG_OUTPUT,
+				      &msynth->output_rfile);
+	if (err < 0) {
+		pr_debug("ALSA: seq_midi: midi output open failed!!!\n");
+		return err;
+	}
+	memset(&params, 0, sizeof(params));
+	params.avail_min = 1;
+	params.buffer_size = output_buffer_size;
+	params.no_active_sensing = 1;
+	err = snd_rawmidi_output_params(msynth->output_rfile.output, &params);
+	if (err < 0) {
+		snd_rawmidi_kernel_release(&msynth->output_rfile);
+		return err;
+	}
+	snd_midi_event_reset_decode(msynth->parser);
+	return 0;
+}
+
+/* close associated midi device for output */
+static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info)
+{
+	struct seq_midisynth *msynth = private_data;
+
+	if (snd_BUG_ON(!msynth->output_rfile.output))
+		return -EINVAL;
+	snd_rawmidi_drain_output(msynth->output_rfile.output);
+	return snd_rawmidi_kernel_release(&msynth->output_rfile);
+}
+
+/* delete given midi synth port */
+static void snd_seq_midisynth_delete(struct seq_midisynth *msynth)
+{
+	if (msynth == NULL)
+		return;
+
+	if (msynth->seq_client > 0) {
+		/* delete port */
+		snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port);
+	}
+
+	snd_midi_event_free(msynth->parser);
+}
+
+/* register new midi synth port */
+static int
+snd_seq_midisynth_probe(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	struct seq_midisynth_client *client;
+	struct seq_midisynth *msynth, *ms;
+	struct snd_seq_port_info *port;
+	struct snd_rawmidi_info *info;
+	struct snd_rawmidi *rmidi = dev->private_data;
+	int newclient = 0;
+	unsigned int p, ports;
+	struct snd_seq_port_callback pcallbacks;
+	struct snd_card *card = dev->card;
+	int device = dev->device;
+	unsigned int input_count = 0, output_count = 0;
+
+	if (snd_BUG_ON(!card || device < 0 || device >= SNDRV_RAWMIDI_DEVICES))
+		return -EINVAL;
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (! info)
+		return -ENOMEM;
+	info->device = device;
+	info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
+	info->subdevice = 0;
+	if (snd_rawmidi_info_select(card, info) >= 0)
+		output_count = info->subdevices_count;
+	info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
+	if (snd_rawmidi_info_select(card, info) >= 0) {
+		input_count = info->subdevices_count;
+	}
+	ports = output_count;
+	if (ports < input_count)
+		ports = input_count;
+	if (ports == 0) {
+		kfree(info);
+		return -ENODEV;
+	}
+	if (ports > (256 / SNDRV_RAWMIDI_DEVICES))
+		ports = 256 / SNDRV_RAWMIDI_DEVICES;
+
+	mutex_lock(&register_mutex);
+	client = synths[card->number];
+	if (client == NULL) {
+		newclient = 1;
+		client = kzalloc(sizeof(*client), GFP_KERNEL);
+		if (client == NULL) {
+			mutex_unlock(&register_mutex);
+			kfree(info);
+			return -ENOMEM;
+		}
+		client->seq_client =
+			snd_seq_create_kernel_client(
+				card, 0, "%s", card->shortname[0] ?
+				(const char *)card->shortname : "External MIDI");
+		if (client->seq_client < 0) {
+			kfree(client);
+			mutex_unlock(&register_mutex);
+			kfree(info);
+			return -ENOMEM;
+		}
+	}
+
+	msynth = kcalloc(ports, sizeof(struct seq_midisynth), GFP_KERNEL);
+	port = kmalloc(sizeof(*port), GFP_KERNEL);
+	if (msynth == NULL || port == NULL)
+		goto __nomem;
+
+	for (p = 0; p < ports; p++) {
+		ms = &msynth[p];
+		ms->rmidi = rmidi;
+
+		if (snd_seq_midisynth_new(ms, card, device, p) < 0)
+			goto __nomem;
+
+		/* declare port */
+		memset(port, 0, sizeof(*port));
+		port->addr.client = client->seq_client;
+		port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p;
+		port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+		memset(info, 0, sizeof(*info));
+		info->device = device;
+		if (p < output_count)
+			info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
+		else
+			info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
+		info->subdevice = p;
+		if (snd_rawmidi_info_select(card, info) >= 0)
+			strcpy(port->name, info->subname);
+		if (! port->name[0]) {
+			if (info->name[0]) {
+				if (ports > 1)
+					scnprintf(port->name, sizeof(port->name), "%s-%u", info->name, p);
+				else
+					scnprintf(port->name, sizeof(port->name), "%s", info->name);
+			} else {
+				/* last resort */
+				if (ports > 1)
+					sprintf(port->name, "MIDI %d-%d-%u", card->number, device, p);
+				else
+					sprintf(port->name, "MIDI %d-%d", card->number, device);
+			}
+		}
+		if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count)
+			port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+		if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count)
+			port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
+		if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) &&
+		    info->flags & SNDRV_RAWMIDI_INFO_DUPLEX)
+			port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+		if (port->capability & SNDRV_SEQ_PORT_CAP_READ)
+			port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+		if (port->capability & SNDRV_SEQ_PORT_CAP_WRITE)
+			port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
+		port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
+			| SNDRV_SEQ_PORT_TYPE_HARDWARE
+			| SNDRV_SEQ_PORT_TYPE_PORT;
+		port->midi_channels = 16;
+		memset(&pcallbacks, 0, sizeof(pcallbacks));
+		pcallbacks.owner = THIS_MODULE;
+		pcallbacks.private_data = ms;
+		pcallbacks.subscribe = midisynth_subscribe;
+		pcallbacks.unsubscribe = midisynth_unsubscribe;
+		pcallbacks.use = midisynth_use;
+		pcallbacks.unuse = midisynth_unuse;
+		pcallbacks.event_input = event_process_midi;
+		port->kernel = &pcallbacks;
+		if (rmidi->ops && rmidi->ops->get_port_info)
+			rmidi->ops->get_port_info(rmidi, p, port);
+		if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0)
+			goto __nomem;
+		ms->seq_client = client->seq_client;
+		ms->seq_port = port->addr.port;
+	}
+	client->ports_per_device[device] = ports;
+	client->ports[device] = msynth;
+	client->num_ports++;
+	if (newclient)
+		synths[card->number] = client;
+	mutex_unlock(&register_mutex);
+	kfree(info);
+	kfree(port);
+	return 0;	/* success */
+
+      __nomem:
+	if (msynth != NULL) {
+	      	for (p = 0; p < ports; p++)
+	      		snd_seq_midisynth_delete(&msynth[p]);
+		kfree(msynth);
+	}
+	if (newclient) {
+		snd_seq_delete_kernel_client(client->seq_client);
+		kfree(client);
+	}
+	kfree(info);
+	kfree(port);
+	mutex_unlock(&register_mutex);
+	return -ENOMEM;
+}
+
+/* release midi synth port */
+static int
+snd_seq_midisynth_remove(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	struct seq_midisynth_client *client;
+	struct seq_midisynth *msynth;
+	struct snd_card *card = dev->card;
+	int device = dev->device, p, ports;
+	
+	mutex_lock(&register_mutex);
+	client = synths[card->number];
+	if (client == NULL || client->ports[device] == NULL) {
+		mutex_unlock(&register_mutex);
+		return -ENODEV;
+	}
+	ports = client->ports_per_device[device];
+	client->ports_per_device[device] = 0;
+	msynth = client->ports[device];
+	client->ports[device] = NULL;
+	for (p = 0; p < ports; p++)
+		snd_seq_midisynth_delete(&msynth[p]);
+	kfree(msynth);
+	client->num_ports--;
+	if (client->num_ports <= 0) {
+		snd_seq_delete_kernel_client(client->seq_client);
+		synths[card->number] = NULL;
+		kfree(client);
+	}
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+static struct snd_seq_driver seq_midisynth_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.probe = snd_seq_midisynth_probe,
+		.remove = snd_seq_midisynth_remove,
+	},
+	.id = SNDRV_SEQ_DEV_ID_MIDISYNTH,
+	.argsize = 0,
+};
+
+module_snd_seq_driver(seq_midisynth_driver);
diff --git a/sound/core/seq/seq_midi_emul.c b/sound/core/seq/seq_midi_emul.c
new file mode 100644
index 0000000000..81d2ef5e58
--- /dev/null
+++ b/sound/core/seq/seq_midi_emul.c
@@ -0,0 +1,723 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  GM/GS/XG midi module.
+ *
+ *  Copyright (C) 1999 Steve Ratcliffe
+ *
+ *  Based on awe_wave.c by Takashi Iwai
+ */
+/*
+ * This module is used to keep track of the current midi state.
+ * It can be used for drivers that are required to emulate midi when
+ * the hardware doesn't.
+ *
+ * It was written for a AWE64 driver, but there should be no AWE specific
+ * code in here.  If there is it should be reported as a bug.
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/seq_kernel.h>
+#include <sound/seq_midi_emul.h>
+#include <sound/initval.h>
+#include <sound/asoundef.h>
+
+MODULE_AUTHOR("Takashi Iwai / Steve Ratcliffe");
+MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI emulation.");
+MODULE_LICENSE("GPL");
+
+/* Prototypes for static functions */
+static void note_off(const struct snd_midi_op *ops, void *drv,
+		     struct snd_midi_channel *chan,
+		     int note, int vel);
+static void do_control(const struct snd_midi_op *ops, void *private,
+		       struct snd_midi_channel_set *chset,
+		       struct snd_midi_channel *chan,
+		       int control, int value);
+static void rpn(const struct snd_midi_op *ops, void *drv,
+		struct snd_midi_channel *chan,
+		struct snd_midi_channel_set *chset);
+static void nrpn(const struct snd_midi_op *ops, void *drv,
+		 struct snd_midi_channel *chan,
+		 struct snd_midi_channel_set *chset);
+static void sysex(const struct snd_midi_op *ops, void *private,
+		  unsigned char *sysex,
+		  int len, struct snd_midi_channel_set *chset);
+static void all_sounds_off(const struct snd_midi_op *ops, void *private,
+			   struct snd_midi_channel *chan);
+static void all_notes_off(const struct snd_midi_op *ops, void *private,
+			  struct snd_midi_channel *chan);
+static void snd_midi_reset_controllers(struct snd_midi_channel *chan);
+static void reset_all_channels(struct snd_midi_channel_set *chset);
+
+
+/*
+ * Process an event in a driver independent way.  This means dealing
+ * with RPN, NRPN, SysEx etc that are defined for common midi applications
+ * such as GM, GS and XG.
+ * There modes that this module will run in are:
+ *   Generic MIDI - no interpretation at all, it will just save current values
+ *                  of controllers etc.
+ *   GM - You can use all gm_ prefixed elements of chan.  Controls, RPN, NRPN,
+ *        SysEx will be interpreded as defined in General Midi.
+ *   GS - You can use all gs_ prefixed elements of chan. Codes for GS will be
+ *        interpreted.
+ *   XG - You can use all xg_ prefixed elements of chan.  Codes for XG will
+ *        be interpreted.
+ */
+void
+snd_midi_process_event(const struct snd_midi_op *ops,
+		       struct snd_seq_event *ev,
+		       struct snd_midi_channel_set *chanset)
+{
+	struct snd_midi_channel *chan;
+	void *drv;
+	int dest_channel = 0;
+
+	if (ev == NULL || chanset == NULL) {
+		pr_debug("ALSA: seq_midi_emul: ev or chanbase NULL (snd_midi_process_event)\n");
+		return;
+	}
+	if (chanset->channels == NULL)
+		return;
+
+	if (snd_seq_ev_is_channel_type(ev)) {
+		dest_channel = ev->data.note.channel;
+		if (dest_channel >= chanset->max_channels) {
+			pr_debug("ALSA: seq_midi_emul: dest channel is %d, max is %d\n",
+				   dest_channel, chanset->max_channels);
+			return;
+		}
+	}
+
+	chan = chanset->channels + dest_channel;
+	drv  = chanset->private_data;
+
+	/* EVENT_NOTE should be processed before queued */
+	if (ev->type == SNDRV_SEQ_EVENT_NOTE)
+		return;
+
+	/* Make sure that we don't have a note on that should really be
+	 * a note off */
+	if (ev->type == SNDRV_SEQ_EVENT_NOTEON && ev->data.note.velocity == 0)
+		ev->type = SNDRV_SEQ_EVENT_NOTEOFF;
+
+	/* Make sure the note is within array range */
+	if (ev->type == SNDRV_SEQ_EVENT_NOTEON ||
+	    ev->type == SNDRV_SEQ_EVENT_NOTEOFF ||
+	    ev->type == SNDRV_SEQ_EVENT_KEYPRESS) {
+		if (ev->data.note.note >= 128)
+			return;
+	}
+
+	switch (ev->type) {
+	case SNDRV_SEQ_EVENT_NOTEON:
+		if (chan->note[ev->data.note.note] & SNDRV_MIDI_NOTE_ON) {
+			if (ops->note_off)
+				ops->note_off(drv, ev->data.note.note, 0, chan);
+		}
+		chan->note[ev->data.note.note] = SNDRV_MIDI_NOTE_ON;
+		if (ops->note_on)
+			ops->note_on(drv, ev->data.note.note, ev->data.note.velocity, chan);
+		break;
+	case SNDRV_SEQ_EVENT_NOTEOFF:
+		if (! (chan->note[ev->data.note.note] & SNDRV_MIDI_NOTE_ON))
+			break;
+		if (ops->note_off)
+			note_off(ops, drv, chan, ev->data.note.note, ev->data.note.velocity);
+		break;
+	case SNDRV_SEQ_EVENT_KEYPRESS:
+		if (ops->key_press)
+			ops->key_press(drv, ev->data.note.note, ev->data.note.velocity, chan);
+		break;
+	case SNDRV_SEQ_EVENT_CONTROLLER:
+		do_control(ops, drv, chanset, chan,
+			   ev->data.control.param, ev->data.control.value);
+		break;
+	case SNDRV_SEQ_EVENT_PGMCHANGE:
+		chan->midi_program = ev->data.control.value;
+		break;
+	case SNDRV_SEQ_EVENT_PITCHBEND:
+		chan->midi_pitchbend = ev->data.control.value;
+		if (ops->control)
+			ops->control(drv, MIDI_CTL_PITCHBEND, chan);
+		break;
+	case SNDRV_SEQ_EVENT_CHANPRESS:
+		chan->midi_pressure = ev->data.control.value;
+		if (ops->control)
+			ops->control(drv, MIDI_CTL_CHAN_PRESSURE, chan);
+		break;
+	case SNDRV_SEQ_EVENT_CONTROL14:
+		/* Best guess is that this is any of the 14 bit controller values */
+		if (ev->data.control.param < 32) {
+			/* set low part first */
+			chan->control[ev->data.control.param + 32] =
+				ev->data.control.value & 0x7f;
+			do_control(ops, drv, chanset, chan,
+				   ev->data.control.param,
+				   ((ev->data.control.value>>7) & 0x7f));
+		} else
+			do_control(ops, drv, chanset, chan,
+				   ev->data.control.param,
+				   ev->data.control.value);
+		break;
+	case SNDRV_SEQ_EVENT_NONREGPARAM:
+		/* Break it back into its controller values */
+		chan->param_type = SNDRV_MIDI_PARAM_TYPE_NONREGISTERED;
+		chan->control[MIDI_CTL_MSB_DATA_ENTRY]
+			= (ev->data.control.value >> 7) & 0x7f;
+		chan->control[MIDI_CTL_LSB_DATA_ENTRY]
+			= ev->data.control.value & 0x7f;
+		chan->control[MIDI_CTL_NONREG_PARM_NUM_MSB]
+			= (ev->data.control.param >> 7) & 0x7f;
+		chan->control[MIDI_CTL_NONREG_PARM_NUM_LSB]
+			= ev->data.control.param & 0x7f;
+		nrpn(ops, drv, chan, chanset);
+		break;
+	case SNDRV_SEQ_EVENT_REGPARAM:
+		/* Break it back into its controller values */
+		chan->param_type = SNDRV_MIDI_PARAM_TYPE_REGISTERED;
+		chan->control[MIDI_CTL_MSB_DATA_ENTRY]
+			= (ev->data.control.value >> 7) & 0x7f;
+		chan->control[MIDI_CTL_LSB_DATA_ENTRY]
+			= ev->data.control.value & 0x7f;
+		chan->control[MIDI_CTL_REGIST_PARM_NUM_MSB]
+			= (ev->data.control.param >> 7) & 0x7f;
+		chan->control[MIDI_CTL_REGIST_PARM_NUM_LSB]
+			= ev->data.control.param & 0x7f;
+		rpn(ops, drv, chan, chanset);
+		break;
+	case SNDRV_SEQ_EVENT_SYSEX:
+		if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) == SNDRV_SEQ_EVENT_LENGTH_VARIABLE) {
+			unsigned char sysexbuf[64];
+			int len;
+			len = snd_seq_expand_var_event(ev, sizeof(sysexbuf), sysexbuf, 1, 0);
+			if (len > 0)
+				sysex(ops, drv, sysexbuf, len, chanset);
+		}
+		break;
+	case SNDRV_SEQ_EVENT_SONGPOS:
+	case SNDRV_SEQ_EVENT_SONGSEL:
+	case SNDRV_SEQ_EVENT_CLOCK:
+	case SNDRV_SEQ_EVENT_START:
+	case SNDRV_SEQ_EVENT_CONTINUE:
+	case SNDRV_SEQ_EVENT_STOP:
+	case SNDRV_SEQ_EVENT_QFRAME:
+	case SNDRV_SEQ_EVENT_TEMPO:
+	case SNDRV_SEQ_EVENT_TIMESIGN:
+	case SNDRV_SEQ_EVENT_KEYSIGN:
+		goto not_yet;
+	case SNDRV_SEQ_EVENT_SENSING:
+		break;
+	case SNDRV_SEQ_EVENT_CLIENT_START:
+	case SNDRV_SEQ_EVENT_CLIENT_EXIT:
+	case SNDRV_SEQ_EVENT_CLIENT_CHANGE:
+	case SNDRV_SEQ_EVENT_PORT_START:
+	case SNDRV_SEQ_EVENT_PORT_EXIT:
+	case SNDRV_SEQ_EVENT_PORT_CHANGE:
+	case SNDRV_SEQ_EVENT_ECHO:
+	not_yet:
+	default:
+		/*pr_debug("ALSA: seq_midi_emul: Unimplemented event %d\n", ev->type);*/
+		break;
+	}
+}
+EXPORT_SYMBOL(snd_midi_process_event);
+
+
+/*
+ * release note
+ */
+static void
+note_off(const struct snd_midi_op *ops, void *drv,
+	 struct snd_midi_channel *chan,
+	 int note, int vel)
+{
+	if (chan->gm_hold) {
+		/* Hold this note until pedal is turned off */
+		chan->note[note] |= SNDRV_MIDI_NOTE_RELEASED;
+	} else if (chan->note[note] & SNDRV_MIDI_NOTE_SOSTENUTO) {
+		/* Mark this note as release; it will be turned off when sostenuto
+		 * is turned off */
+		chan->note[note] |= SNDRV_MIDI_NOTE_RELEASED;
+	} else {
+		chan->note[note] = 0;
+		if (ops->note_off)
+			ops->note_off(drv, note, vel, chan);
+	}
+}
+
+/*
+ * Do all driver independent operations for this controller and pass
+ * events that need to take place immediately to the driver.
+ */
+static void
+do_control(const struct snd_midi_op *ops, void *drv,
+	   struct snd_midi_channel_set *chset,
+	   struct snd_midi_channel *chan, int control, int value)
+{
+	int  i;
+
+	if (control >= ARRAY_SIZE(chan->control))
+		return;
+
+	/* Switches */
+	if ((control >=64 && control <=69) || (control >= 80 && control <= 83)) {
+		/* These are all switches; either off or on so set to 0 or 127 */
+		value = (value >= 64)? 127: 0;
+	}
+	chan->control[control] = value;
+
+	switch (control) {
+	case MIDI_CTL_SUSTAIN:
+		if (value == 0) {
+			/* Sustain has been released, turn off held notes */
+			for (i = 0; i < 128; i++) {
+				if (chan->note[i] & SNDRV_MIDI_NOTE_RELEASED) {
+					chan->note[i] = SNDRV_MIDI_NOTE_OFF;
+					if (ops->note_off)
+						ops->note_off(drv, i, 0, chan);
+				}
+			}
+		}
+		break;
+	case MIDI_CTL_PORTAMENTO:
+		break;
+	case MIDI_CTL_SOSTENUTO:
+		if (value) {
+			/* Mark each note that is currently held down */
+			for (i = 0; i < 128; i++) {
+				if (chan->note[i] & SNDRV_MIDI_NOTE_ON)
+					chan->note[i] |= SNDRV_MIDI_NOTE_SOSTENUTO;
+			}
+		} else {
+			/* release all notes that were held */
+			for (i = 0; i < 128; i++) {
+				if (chan->note[i] & SNDRV_MIDI_NOTE_SOSTENUTO) {
+					chan->note[i] &= ~SNDRV_MIDI_NOTE_SOSTENUTO;
+					if (chan->note[i] & SNDRV_MIDI_NOTE_RELEASED) {
+						chan->note[i] = SNDRV_MIDI_NOTE_OFF;
+						if (ops->note_off)
+							ops->note_off(drv, i, 0, chan);
+					}
+				}
+			}
+		}
+		break;
+	case MIDI_CTL_MSB_DATA_ENTRY:
+		chan->control[MIDI_CTL_LSB_DATA_ENTRY] = 0;
+		fallthrough;
+	case MIDI_CTL_LSB_DATA_ENTRY:
+		if (chan->param_type == SNDRV_MIDI_PARAM_TYPE_REGISTERED)
+			rpn(ops, drv, chan, chset);
+		else
+			nrpn(ops, drv, chan, chset);
+		break;
+	case MIDI_CTL_REGIST_PARM_NUM_LSB:
+	case MIDI_CTL_REGIST_PARM_NUM_MSB:
+		chan->param_type = SNDRV_MIDI_PARAM_TYPE_REGISTERED;
+		break;
+	case MIDI_CTL_NONREG_PARM_NUM_LSB:
+	case MIDI_CTL_NONREG_PARM_NUM_MSB:
+		chan->param_type = SNDRV_MIDI_PARAM_TYPE_NONREGISTERED;
+		break;
+
+	case MIDI_CTL_ALL_SOUNDS_OFF:
+		all_sounds_off(ops, drv, chan);
+		break;
+
+	case MIDI_CTL_ALL_NOTES_OFF:
+		all_notes_off(ops, drv, chan);
+		break;
+
+	case MIDI_CTL_MSB_BANK:
+		if (chset->midi_mode == SNDRV_MIDI_MODE_XG) {
+			if (value == 127)
+				chan->drum_channel = 1;
+			else
+				chan->drum_channel = 0;
+		}
+		break;
+	case MIDI_CTL_LSB_BANK:
+		break;
+
+	case MIDI_CTL_RESET_CONTROLLERS:
+		snd_midi_reset_controllers(chan);
+		break;
+
+	case MIDI_CTL_SOFT_PEDAL:
+	case MIDI_CTL_LEGATO_FOOTSWITCH:
+	case MIDI_CTL_HOLD2:
+	case MIDI_CTL_SC1_SOUND_VARIATION:
+	case MIDI_CTL_SC2_TIMBRE:
+	case MIDI_CTL_SC3_RELEASE_TIME:
+	case MIDI_CTL_SC4_ATTACK_TIME:
+	case MIDI_CTL_SC5_BRIGHTNESS:
+	case MIDI_CTL_E1_REVERB_DEPTH:
+	case MIDI_CTL_E2_TREMOLO_DEPTH:
+	case MIDI_CTL_E3_CHORUS_DEPTH:
+	case MIDI_CTL_E4_DETUNE_DEPTH:
+	case MIDI_CTL_E5_PHASER_DEPTH:
+		goto notyet;
+	notyet:
+	default:
+		if (ops->control)
+			ops->control(drv, control, chan);
+		break;
+	}
+}
+
+
+/*
+ * initialize the MIDI status
+ */
+void
+snd_midi_channel_set_clear(struct snd_midi_channel_set *chset)
+{
+	int i;
+
+	chset->midi_mode = SNDRV_MIDI_MODE_GM;
+	chset->gs_master_volume = 127;
+
+	for (i = 0; i < chset->max_channels; i++) {
+		struct snd_midi_channel *chan = chset->channels + i;
+		memset(chan->note, 0, sizeof(chan->note));
+
+		chan->midi_aftertouch = 0;
+		chan->midi_pressure = 0;
+		chan->midi_program = 0;
+		chan->midi_pitchbend = 0;
+		snd_midi_reset_controllers(chan);
+		chan->gm_rpn_pitch_bend_range = 256; /* 2 semitones */
+		chan->gm_rpn_fine_tuning = 0;
+		chan->gm_rpn_coarse_tuning = 0;
+
+		if (i == 9)
+			chan->drum_channel = 1;
+		else
+			chan->drum_channel = 0;
+	}
+}
+EXPORT_SYMBOL(snd_midi_channel_set_clear);
+
+/*
+ * Process a rpn message.
+ */
+static void
+rpn(const struct snd_midi_op *ops, void *drv, struct snd_midi_channel *chan,
+    struct snd_midi_channel_set *chset)
+{
+	int type;
+	int val;
+
+	if (chset->midi_mode != SNDRV_MIDI_MODE_NONE) {
+		type = (chan->control[MIDI_CTL_REGIST_PARM_NUM_MSB] << 8) |
+			chan->control[MIDI_CTL_REGIST_PARM_NUM_LSB];
+		val = (chan->control[MIDI_CTL_MSB_DATA_ENTRY] << 7) |
+			chan->control[MIDI_CTL_LSB_DATA_ENTRY];
+
+		switch (type) {
+		case 0x0000: /* Pitch bend sensitivity */
+			/* MSB only / 1 semitone per 128 */
+			chan->gm_rpn_pitch_bend_range = val;
+			break;
+					
+		case 0x0001: /* fine tuning: */
+			/* MSB/LSB, 8192=center, 100/8192 cent step */
+			chan->gm_rpn_fine_tuning = val - 8192;
+			break;
+
+		case 0x0002: /* coarse tuning */
+			/* MSB only / 8192=center, 1 semitone per 128 */
+			chan->gm_rpn_coarse_tuning = val - 8192;
+			break;
+
+		case 0x7F7F: /* "lock-in" RPN */
+			/* ignored */
+			break;
+		}
+	}
+	/* should call nrpn or rpn callback here.. */
+}
+
+/*
+ * Process an nrpn message.
+ */
+static void
+nrpn(const struct snd_midi_op *ops, void *drv, struct snd_midi_channel *chan,
+     struct snd_midi_channel_set *chset)
+{
+	/* parse XG NRPNs here if possible */
+	if (ops->nrpn)
+		ops->nrpn(drv, chan, chset);
+}
+
+
+/*
+ * convert channel parameter in GS sysex
+ */
+static int
+get_channel(unsigned char cmd)
+{
+	int p = cmd & 0x0f;
+	if (p == 0)
+		p = 9;
+	else if (p < 10)
+		p--;
+	return p;
+}
+
+
+/*
+ * Process a sysex message.
+ */
+static void
+sysex(const struct snd_midi_op *ops, void *private, unsigned char *buf, int len,
+      struct snd_midi_channel_set *chset)
+{
+	/* GM on */
+	static const unsigned char gm_on_macro[] = {
+		0x7e,0x7f,0x09,0x01,
+	};
+	/* XG on */
+	static const unsigned char xg_on_macro[] = {
+		0x43,0x10,0x4c,0x00,0x00,0x7e,0x00,
+	};
+	/* GS prefix
+	 * drum channel: XX=0x1?(channel), YY=0x15, ZZ=on/off
+	 * reverb mode: XX=0x01, YY=0x30, ZZ=0-7
+	 * chorus mode: XX=0x01, YY=0x38, ZZ=0-7
+	 * master vol:  XX=0x00, YY=0x04, ZZ=0-127
+	 */
+	static const unsigned char gs_pfx_macro[] = {
+		0x41,0x10,0x42,0x12,0x40,/*XX,YY,ZZ*/
+	};
+
+	int parsed = SNDRV_MIDI_SYSEX_NOT_PARSED;
+
+	if (len <= 0 || buf[0] != 0xf0)
+		return;
+	/* skip first byte */
+	buf++;
+	len--;
+
+	/* GM on */
+	if (len >= (int)sizeof(gm_on_macro) &&
+	    memcmp(buf, gm_on_macro, sizeof(gm_on_macro)) == 0) {
+		if (chset->midi_mode != SNDRV_MIDI_MODE_GS &&
+		    chset->midi_mode != SNDRV_MIDI_MODE_XG) {
+			chset->midi_mode = SNDRV_MIDI_MODE_GM;
+			reset_all_channels(chset);
+			parsed = SNDRV_MIDI_SYSEX_GM_ON;
+		}
+	}
+
+	/* GS macros */
+	else if (len >= 8 &&
+		 memcmp(buf, gs_pfx_macro, sizeof(gs_pfx_macro)) == 0) {
+		if (chset->midi_mode != SNDRV_MIDI_MODE_GS &&
+		    chset->midi_mode != SNDRV_MIDI_MODE_XG)
+			chset->midi_mode = SNDRV_MIDI_MODE_GS;
+
+		if (buf[5] == 0x00 && buf[6] == 0x7f && buf[7] == 0x00) {
+			/* GS reset */
+			parsed = SNDRV_MIDI_SYSEX_GS_RESET;
+			reset_all_channels(chset);
+		}
+
+		else if ((buf[5] & 0xf0) == 0x10 && buf[6] == 0x15) {
+			/* drum pattern */
+			int p = get_channel(buf[5]);
+			if (p < chset->max_channels) {
+				parsed = SNDRV_MIDI_SYSEX_GS_DRUM_CHANNEL;
+				if (buf[7])
+					chset->channels[p].drum_channel = 1;
+				else
+					chset->channels[p].drum_channel = 0;
+			}
+
+		} else if ((buf[5] & 0xf0) == 0x10 && buf[6] == 0x21) {
+			/* program */
+			int p = get_channel(buf[5]);
+			if (p < chset->max_channels &&
+			    ! chset->channels[p].drum_channel) {
+				parsed = SNDRV_MIDI_SYSEX_GS_DRUM_CHANNEL;
+				chset->channels[p].midi_program = buf[7];
+			}
+
+		} else if (buf[5] == 0x01 && buf[6] == 0x30) {
+			/* reverb mode */
+			parsed = SNDRV_MIDI_SYSEX_GS_REVERB_MODE;
+			chset->gs_reverb_mode = buf[7];
+
+		} else if (buf[5] == 0x01 && buf[6] == 0x38) {
+			/* chorus mode */
+			parsed = SNDRV_MIDI_SYSEX_GS_CHORUS_MODE;
+			chset->gs_chorus_mode = buf[7];
+
+		} else if (buf[5] == 0x00 && buf[6] == 0x04) {
+			/* master volume */
+			parsed = SNDRV_MIDI_SYSEX_GS_MASTER_VOLUME;
+			chset->gs_master_volume = buf[7];
+
+		}
+	}
+
+	/* XG on */
+	else if (len >= (int)sizeof(xg_on_macro) &&
+		 memcmp(buf, xg_on_macro, sizeof(xg_on_macro)) == 0) {
+		int i;
+		chset->midi_mode = SNDRV_MIDI_MODE_XG;
+		parsed = SNDRV_MIDI_SYSEX_XG_ON;
+		/* reset CC#0 for drums */
+		for (i = 0; i < chset->max_channels; i++) {
+			if (chset->channels[i].drum_channel)
+				chset->channels[i].control[MIDI_CTL_MSB_BANK] = 127;
+			else
+				chset->channels[i].control[MIDI_CTL_MSB_BANK] = 0;
+		}
+	}
+
+	if (ops->sysex)
+		ops->sysex(private, buf - 1, len + 1, parsed, chset);
+}
+
+/*
+ * all sound off
+ */
+static void
+all_sounds_off(const struct snd_midi_op *ops, void *drv,
+	       struct snd_midi_channel *chan)
+{
+	int n;
+
+	if (! ops->note_terminate)
+		return;
+	for (n = 0; n < 128; n++) {
+		if (chan->note[n]) {
+			ops->note_terminate(drv, n, chan);
+			chan->note[n] = 0;
+		}
+	}
+}
+
+/*
+ * all notes off
+ */
+static void
+all_notes_off(const struct snd_midi_op *ops, void *drv,
+	      struct snd_midi_channel *chan)
+{
+	int n;
+
+	if (! ops->note_off)
+		return;
+	for (n = 0; n < 128; n++) {
+		if (chan->note[n] == SNDRV_MIDI_NOTE_ON)
+			note_off(ops, drv, chan, n, 0);
+	}
+}
+
+/*
+ * Initialise a single midi channel control block.
+ */
+static void snd_midi_channel_init(struct snd_midi_channel *p, int n)
+{
+	if (p == NULL)
+		return;
+
+	memset(p, 0, sizeof(struct snd_midi_channel));
+	p->private = NULL;
+	p->number = n;
+
+	snd_midi_reset_controllers(p);
+	p->gm_rpn_pitch_bend_range = 256; /* 2 semitones */
+	p->gm_rpn_fine_tuning = 0;
+	p->gm_rpn_coarse_tuning = 0;
+
+	if (n == 9)
+		p->drum_channel = 1;	/* Default ch 10 as drums */
+}
+
+/*
+ * Allocate and initialise a set of midi channel control blocks.
+ */
+static struct snd_midi_channel *snd_midi_channel_init_set(int n)
+{
+	struct snd_midi_channel *chan;
+	int  i;
+
+	chan = kmalloc_array(n, sizeof(struct snd_midi_channel), GFP_KERNEL);
+	if (chan) {
+		for (i = 0; i < n; i++)
+			snd_midi_channel_init(chan+i, i);
+	}
+
+	return chan;
+}
+
+/*
+ * reset all midi channels
+ */
+static void
+reset_all_channels(struct snd_midi_channel_set *chset)
+{
+	int ch;
+	for (ch = 0; ch < chset->max_channels; ch++) {
+		struct snd_midi_channel *chan = chset->channels + ch;
+		snd_midi_reset_controllers(chan);
+		chan->gm_rpn_pitch_bend_range = 256; /* 2 semitones */
+		chan->gm_rpn_fine_tuning = 0;
+		chan->gm_rpn_coarse_tuning = 0;
+
+		if (ch == 9)
+			chan->drum_channel = 1;
+		else
+			chan->drum_channel = 0;
+	}
+}
+
+
+/*
+ * Allocate and initialise a midi channel set.
+ */
+struct snd_midi_channel_set *snd_midi_channel_alloc_set(int n)
+{
+	struct snd_midi_channel_set *chset;
+
+	chset = kmalloc(sizeof(*chset), GFP_KERNEL);
+	if (chset) {
+		chset->channels = snd_midi_channel_init_set(n);
+		chset->private_data = NULL;
+		chset->max_channels = n;
+	}
+	return chset;
+}
+EXPORT_SYMBOL(snd_midi_channel_alloc_set);
+
+/*
+ * Reset the midi controllers on a particular channel to default values.
+ */
+static void snd_midi_reset_controllers(struct snd_midi_channel *chan)
+{
+	memset(chan->control, 0, sizeof(chan->control));
+	chan->gm_volume = 127;
+	chan->gm_expression = 127;
+	chan->gm_pan = 64;
+}
+
+
+/*
+ * Free a midi channel set.
+ */
+void snd_midi_channel_free_set(struct snd_midi_channel_set *chset)
+{
+	if (chset == NULL)
+		return;
+	kfree(chset->channels);
+	kfree(chset);
+}
+EXPORT_SYMBOL(snd_midi_channel_free_set);
diff --git a/sound/core/seq/seq_midi_event.c b/sound/core/seq/seq_midi_event.c
new file mode 100644
index 0000000000..7511462fe0
--- /dev/null
+++ b/sound/core/seq/seq_midi_event.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  MIDI byte <-> sequencer event coder
+ *
+ *  Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>,
+ *                        Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/seq_kernel.h>
+#include <sound/seq_midi_event.h>
+#include <sound/asoundef.h>
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder");
+MODULE_LICENSE("GPL");
+
+/* event type, index into status_event[] */
+/* from 0 to 6 are normal commands (note off, on, etc.) for 0x9?-0xe? */
+#define ST_INVALID	7
+#define ST_SPECIAL	8
+#define ST_SYSEX	ST_SPECIAL
+/* from 8 to 15 are events for 0xf0-0xf7 */
+
+
+/*
+ * prototypes
+ */
+static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
+static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
+static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
+static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
+static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
+static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
+static void note_decode(struct snd_seq_event *ev, unsigned char *buf);
+static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf);
+static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf);
+static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf);
+static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf);
+
+/*
+ * event list
+ */
+static struct status_event_list {
+	int event;
+	int qlen;
+	void (*encode)(struct snd_midi_event *dev, struct snd_seq_event *ev);
+	void (*decode)(struct snd_seq_event *ev, unsigned char *buf);
+} status_event[] = {
+	/* 0x80 - 0xef */
+	{SNDRV_SEQ_EVENT_NOTEOFF,	 2, note_event, note_decode},
+	{SNDRV_SEQ_EVENT_NOTEON,	 2, note_event, note_decode},
+	{SNDRV_SEQ_EVENT_KEYPRESS,	 2, note_event, note_decode},
+	{SNDRV_SEQ_EVENT_CONTROLLER,	 2, two_param_ctrl_event, two_param_decode},
+	{SNDRV_SEQ_EVENT_PGMCHANGE,	 1, one_param_ctrl_event, one_param_decode},
+	{SNDRV_SEQ_EVENT_CHANPRESS,	 1, one_param_ctrl_event, one_param_decode},
+	{SNDRV_SEQ_EVENT_PITCHBEND,	 2, pitchbend_ctrl_event, pitchbend_decode},
+	/* invalid */
+	{SNDRV_SEQ_EVENT_NONE,		-1, NULL, NULL},
+	/* 0xf0 - 0xff */
+	{SNDRV_SEQ_EVENT_SYSEX,		 1, NULL, NULL}, /* sysex: 0xf0 */
+	{SNDRV_SEQ_EVENT_QFRAME,	 1, one_param_event, one_param_decode}, /* 0xf1 */
+	{SNDRV_SEQ_EVENT_SONGPOS,	 2, songpos_event, songpos_decode}, /* 0xf2 */
+	{SNDRV_SEQ_EVENT_SONGSEL,	 1, one_param_event, one_param_decode}, /* 0xf3 */
+	{SNDRV_SEQ_EVENT_NONE,		-1, NULL, NULL}, /* 0xf4 */
+	{SNDRV_SEQ_EVENT_NONE,		-1, NULL, NULL}, /* 0xf5 */
+	{SNDRV_SEQ_EVENT_TUNE_REQUEST,	 0, NULL, NULL}, /* 0xf6 */
+	{SNDRV_SEQ_EVENT_NONE,		-1, NULL, NULL}, /* 0xf7 */
+	{SNDRV_SEQ_EVENT_CLOCK,		 0, NULL, NULL}, /* 0xf8 */
+	{SNDRV_SEQ_EVENT_NONE,		-1, NULL, NULL}, /* 0xf9 */
+	{SNDRV_SEQ_EVENT_START,		 0, NULL, NULL}, /* 0xfa */
+	{SNDRV_SEQ_EVENT_CONTINUE,	 0, NULL, NULL}, /* 0xfb */
+	{SNDRV_SEQ_EVENT_STOP, 		 0, NULL, NULL}, /* 0xfc */
+	{SNDRV_SEQ_EVENT_NONE, 		-1, NULL, NULL}, /* 0xfd */
+	{SNDRV_SEQ_EVENT_SENSING, 	 0, NULL, NULL}, /* 0xfe */
+	{SNDRV_SEQ_EVENT_RESET, 	 0, NULL, NULL}, /* 0xff */
+};
+
+static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len,
+			       struct snd_seq_event *ev);
+static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf, int count,
+			     struct snd_seq_event *ev);
+
+static struct extra_event_list {
+	int event;
+	int (*decode)(struct snd_midi_event *dev, unsigned char *buf, int len,
+		      struct snd_seq_event *ev);
+} extra_event[] = {
+	{SNDRV_SEQ_EVENT_CONTROL14, extra_decode_ctrl14},
+	{SNDRV_SEQ_EVENT_NONREGPARAM, extra_decode_xrpn},
+	{SNDRV_SEQ_EVENT_REGPARAM, extra_decode_xrpn},
+};
+
+/*
+ *  new/delete record
+ */
+
+int snd_midi_event_new(int bufsize, struct snd_midi_event **rdev)
+{
+	struct snd_midi_event *dev;
+
+	*rdev = NULL;
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL)
+		return -ENOMEM;
+	if (bufsize > 0) {
+		dev->buf = kmalloc(bufsize, GFP_KERNEL);
+		if (dev->buf == NULL) {
+			kfree(dev);
+			return -ENOMEM;
+		}
+	}
+	dev->bufsize = bufsize;
+	dev->lastcmd = 0xff;
+	dev->type = ST_INVALID;
+	spin_lock_init(&dev->lock);
+	*rdev = dev;
+	return 0;
+}
+EXPORT_SYMBOL(snd_midi_event_new);
+
+void snd_midi_event_free(struct snd_midi_event *dev)
+{
+	if (dev != NULL) {
+		kfree(dev->buf);
+		kfree(dev);
+	}
+}
+EXPORT_SYMBOL(snd_midi_event_free);
+
+/*
+ * initialize record
+ */
+static inline void reset_encode(struct snd_midi_event *dev)
+{
+	dev->read = 0;
+	dev->qlen = 0;
+	dev->type = ST_INVALID;
+}
+
+void snd_midi_event_reset_encode(struct snd_midi_event *dev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	reset_encode(dev);
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+EXPORT_SYMBOL(snd_midi_event_reset_encode);
+
+void snd_midi_event_reset_decode(struct snd_midi_event *dev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	dev->lastcmd = 0xff;
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+EXPORT_SYMBOL(snd_midi_event_reset_decode);
+
+void snd_midi_event_no_status(struct snd_midi_event *dev, int on)
+{
+	dev->nostat = on ? 1 : 0;
+}
+EXPORT_SYMBOL(snd_midi_event_no_status);
+
+/*
+ *  read one byte and encode to sequencer event:
+ *  return true if MIDI bytes are encoded to an event
+ *         false data is not finished
+ */
+bool snd_midi_event_encode_byte(struct snd_midi_event *dev, unsigned char c,
+				struct snd_seq_event *ev)
+{
+	bool rc = false;
+	unsigned long flags;
+
+	if (c >= MIDI_CMD_COMMON_CLOCK) {
+		/* real-time event */
+		ev->type = status_event[ST_SPECIAL + c - 0xf0].event;
+		ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+		ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
+		return ev->type != SNDRV_SEQ_EVENT_NONE;
+	}
+
+	spin_lock_irqsave(&dev->lock, flags);
+	if ((c & 0x80) &&
+	    (c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) {
+		/* new command */
+		dev->buf[0] = c;
+		if ((c & 0xf0) == 0xf0) /* system messages */
+			dev->type = (c & 0x0f) + ST_SPECIAL;
+		else
+			dev->type = (c >> 4) & 0x07;
+		dev->read = 1;
+		dev->qlen = status_event[dev->type].qlen;
+	} else {
+		if (dev->qlen > 0) {
+			/* rest of command */
+			dev->buf[dev->read++] = c;
+			if (dev->type != ST_SYSEX)
+				dev->qlen--;
+		} else {
+			/* running status */
+			dev->buf[1] = c;
+			dev->qlen = status_event[dev->type].qlen - 1;
+			dev->read = 2;
+		}
+	}
+	if (dev->qlen == 0) {
+		ev->type = status_event[dev->type].event;
+		ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+		ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
+		if (status_event[dev->type].encode) /* set data values */
+			status_event[dev->type].encode(dev, ev);
+		if (dev->type >= ST_SPECIAL)
+			dev->type = ST_INVALID;
+		rc = true;
+	} else 	if (dev->type == ST_SYSEX) {
+		if (c == MIDI_CMD_COMMON_SYSEX_END ||
+		    dev->read >= dev->bufsize) {
+			ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+			ev->flags |= SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
+			ev->type = SNDRV_SEQ_EVENT_SYSEX;
+			ev->data.ext.len = dev->read;
+			ev->data.ext.ptr = dev->buf;
+			if (c != MIDI_CMD_COMMON_SYSEX_END)
+				dev->read = 0; /* continue to parse */
+			else
+				reset_encode(dev); /* all parsed */
+			rc = true;
+		}
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+	return rc;
+}
+EXPORT_SYMBOL(snd_midi_event_encode_byte);
+
+/* encode note event */
+static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
+{
+	ev->data.note.channel = dev->buf[0] & 0x0f;
+	ev->data.note.note = dev->buf[1];
+	ev->data.note.velocity = dev->buf[2];
+}
+
+/* encode one parameter controls */
+static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
+{
+	ev->data.control.channel = dev->buf[0] & 0x0f;
+	ev->data.control.value = dev->buf[1];
+}
+
+/* encode pitch wheel change */
+static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
+{
+	ev->data.control.channel = dev->buf[0] & 0x0f;
+	ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192;
+}
+
+/* encode midi control change */
+static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
+{
+	ev->data.control.channel = dev->buf[0] & 0x0f;
+	ev->data.control.param = dev->buf[1];
+	ev->data.control.value = dev->buf[2];
+}
+
+/* encode one parameter value*/
+static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
+{
+	ev->data.control.value = dev->buf[1];
+}
+
+/* encode song position */
+static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
+{
+	ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1];
+}
+
+/*
+ * decode from a sequencer event to midi bytes
+ * return the size of decoded midi events
+ */
+long snd_midi_event_decode(struct snd_midi_event *dev, unsigned char *buf, long count,
+			   struct snd_seq_event *ev)
+{
+	unsigned int cmd, type;
+
+	if (ev->type == SNDRV_SEQ_EVENT_NONE)
+		return -ENOENT;
+
+	for (type = 0; type < ARRAY_SIZE(status_event); type++) {
+		if (ev->type == status_event[type].event)
+			goto __found;
+	}
+	for (type = 0; type < ARRAY_SIZE(extra_event); type++) {
+		if (ev->type == extra_event[type].event)
+			return extra_event[type].decode(dev, buf, count, ev);
+	}
+	return -ENOENT;
+
+      __found:
+	if (type >= ST_SPECIAL)
+		cmd = 0xf0 + (type - ST_SPECIAL);
+	else
+		/* data.note.channel and data.control.channel is identical */
+		cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f);
+
+
+	if (cmd == MIDI_CMD_COMMON_SYSEX) {
+		snd_midi_event_reset_decode(dev);
+		return snd_seq_expand_var_event(ev, count, buf, 1, 0);
+	} else {
+		int qlen;
+		unsigned char xbuf[4];
+		unsigned long flags;
+
+		spin_lock_irqsave(&dev->lock, flags);
+		if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) {
+			dev->lastcmd = cmd;
+			spin_unlock_irqrestore(&dev->lock, flags);
+			xbuf[0] = cmd;
+			if (status_event[type].decode)
+				status_event[type].decode(ev, xbuf + 1);
+			qlen = status_event[type].qlen + 1;
+		} else {
+			spin_unlock_irqrestore(&dev->lock, flags);
+			if (status_event[type].decode)
+				status_event[type].decode(ev, xbuf + 0);
+			qlen = status_event[type].qlen;
+		}
+		if (count < qlen)
+			return -ENOMEM;
+		memcpy(buf, xbuf, qlen);
+		return qlen;
+	}
+}
+EXPORT_SYMBOL(snd_midi_event_decode);
+
+
+/* decode note event */
+static void note_decode(struct snd_seq_event *ev, unsigned char *buf)
+{
+	buf[0] = ev->data.note.note & 0x7f;
+	buf[1] = ev->data.note.velocity & 0x7f;
+}
+
+/* decode one parameter controls */
+static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf)
+{
+	buf[0] = ev->data.control.value & 0x7f;
+}
+
+/* decode pitch wheel change */
+static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf)
+{
+	int value = ev->data.control.value + 8192;
+	buf[0] = value & 0x7f;
+	buf[1] = (value >> 7) & 0x7f;
+}
+
+/* decode midi control change */
+static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf)
+{
+	buf[0] = ev->data.control.param & 0x7f;
+	buf[1] = ev->data.control.value & 0x7f;
+}
+
+/* decode song position */
+static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf)
+{
+	buf[0] = ev->data.control.value & 0x7f;
+	buf[1] = (ev->data.control.value >> 7) & 0x7f;
+}
+
+/* decode 14bit control */
+static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf,
+			       int count, struct snd_seq_event *ev)
+{
+	unsigned char cmd;
+	int idx = 0;
+
+	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
+	if (ev->data.control.param < 0x20) {
+		if (count < 4)
+			return -ENOMEM;
+		if (dev->nostat && count < 6)
+			return -ENOMEM;
+		if (cmd != dev->lastcmd || dev->nostat) {
+			if (count < 5)
+				return -ENOMEM;
+			buf[idx++] = dev->lastcmd = cmd;
+		}
+		buf[idx++] = ev->data.control.param;
+		buf[idx++] = (ev->data.control.value >> 7) & 0x7f;
+		if (dev->nostat)
+			buf[idx++] = cmd;
+		buf[idx++] = ev->data.control.param + 0x20;
+		buf[idx++] = ev->data.control.value & 0x7f;
+	} else {
+		if (count < 2)
+			return -ENOMEM;
+		if (cmd != dev->lastcmd || dev->nostat) {
+			if (count < 3)
+				return -ENOMEM;
+			buf[idx++] = dev->lastcmd = cmd;
+		}
+		buf[idx++] = ev->data.control.param & 0x7f;
+		buf[idx++] = ev->data.control.value & 0x7f;
+	}
+	return idx;
+}
+
+/* decode reg/nonreg param */
+static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf,
+			     int count, struct snd_seq_event *ev)
+{
+	unsigned char cmd;
+	const char *cbytes;
+	static const char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
+				       MIDI_CTL_NONREG_PARM_NUM_LSB,
+				       MIDI_CTL_MSB_DATA_ENTRY,
+				       MIDI_CTL_LSB_DATA_ENTRY };
+	static const char cbytes_rpn[4] =  { MIDI_CTL_REGIST_PARM_NUM_MSB,
+				       MIDI_CTL_REGIST_PARM_NUM_LSB,
+				       MIDI_CTL_MSB_DATA_ENTRY,
+				       MIDI_CTL_LSB_DATA_ENTRY };
+	unsigned char bytes[4];
+	int idx = 0, i;
+
+	if (count < 8)
+		return -ENOMEM;
+	if (dev->nostat && count < 12)
+		return -ENOMEM;
+	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
+	bytes[0] = (ev->data.control.param & 0x3f80) >> 7;
+	bytes[1] = ev->data.control.param & 0x007f;
+	bytes[2] = (ev->data.control.value & 0x3f80) >> 7;
+	bytes[3] = ev->data.control.value & 0x007f;
+	if (cmd != dev->lastcmd && !dev->nostat) {
+		if (count < 9)
+			return -ENOMEM;
+		buf[idx++] = dev->lastcmd = cmd;
+	}
+	cbytes = ev->type == SNDRV_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn;
+	for (i = 0; i < 4; i++) {
+		if (dev->nostat)
+			buf[idx++] = dev->lastcmd = cmd;
+		buf[idx++] = cbytes[i];
+		buf[idx++] = bytes[i];
+	}
+	return idx;
+}
diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c
new file mode 100644
index 0000000000..f3f14ff0f8
--- /dev/null
+++ b/sound/core/seq/seq_ports.c
@@ -0,0 +1,741 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer Ports
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *                         Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <sound/core.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include "seq_system.h"
+#include "seq_ports.h"
+#include "seq_clientmgr.h"
+
+/*
+
+   registration of client ports
+
+ */
+
+
+/* 
+
+NOTE: the current implementation of the port structure as a linked list is
+not optimal for clients that have many ports. For sending messages to all
+subscribers of a port we first need to find the address of the port
+structure, which means we have to traverse the list. A direct access table
+(array) would be better, but big preallocated arrays waste memory.
+
+Possible actions:
+
+1) leave it this way, a client does normaly does not have more than a few
+ports
+
+2) replace the linked list of ports by a array of pointers which is
+dynamicly kmalloced. When a port is added or deleted we can simply allocate
+a new array, copy the corresponding pointers, and delete the old one. We
+then only need a pointer to this array, and an integer that tells us how
+much elements are in array.
+
+*/
+
+/* return pointer to port structure - port is locked if found */
+struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client,
+						 int num)
+{
+	struct snd_seq_client_port *port;
+
+	if (client == NULL)
+		return NULL;
+	read_lock(&client->ports_lock);
+	list_for_each_entry(port, &client->ports_list_head, list) {
+		if (port->addr.port == num) {
+			if (port->closing)
+				break; /* deleting now */
+			snd_use_lock_use(&port->use_lock);
+			read_unlock(&client->ports_lock);
+			return port;
+		}
+	}
+	read_unlock(&client->ports_lock);
+	return NULL;		/* not found */
+}
+
+
+/* search for the next port - port is locked if found */
+struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
+						       struct snd_seq_port_info *pinfo)
+{
+	int num;
+	struct snd_seq_client_port *port, *found;
+	bool check_inactive = (pinfo->capability & SNDRV_SEQ_PORT_CAP_INACTIVE);
+
+	num = pinfo->addr.port;
+	found = NULL;
+	read_lock(&client->ports_lock);
+	list_for_each_entry(port, &client->ports_list_head, list) {
+		if ((port->capability & SNDRV_SEQ_PORT_CAP_INACTIVE) &&
+		    !check_inactive)
+			continue; /* skip inactive ports */
+		if (port->addr.port < num)
+			continue;
+		if (port->addr.port == num) {
+			found = port;
+			break;
+		}
+		if (found == NULL || port->addr.port < found->addr.port)
+			found = port;
+	}
+	if (found) {
+		if (found->closing)
+			found = NULL;
+		else
+			snd_use_lock_use(&found->use_lock);
+	}
+	read_unlock(&client->ports_lock);
+	return found;
+}
+
+
+/* initialize snd_seq_port_subs_info */
+static void port_subs_info_init(struct snd_seq_port_subs_info *grp)
+{
+	INIT_LIST_HEAD(&grp->list_head);
+	grp->count = 0;
+	grp->exclusive = 0;
+	rwlock_init(&grp->list_lock);
+	init_rwsem(&grp->list_mutex);
+	grp->open = NULL;
+	grp->close = NULL;
+}
+
+
+/* create a port, port number or a negative error code is returned
+ * the caller needs to unref the port via snd_seq_port_unlock() appropriately
+ */
+int snd_seq_create_port(struct snd_seq_client *client, int port,
+			struct snd_seq_client_port **port_ret)
+{
+	struct snd_seq_client_port *new_port, *p;
+	int num;
+	
+	*port_ret = NULL;
+
+	/* sanity check */
+	if (snd_BUG_ON(!client))
+		return -EINVAL;
+
+	if (client->num_ports >= SNDRV_SEQ_MAX_PORTS) {
+		pr_warn("ALSA: seq: too many ports for client %d\n", client->number);
+		return -EINVAL;
+	}
+
+	/* create a new port */
+	new_port = kzalloc(sizeof(*new_port), GFP_KERNEL);
+	if (!new_port)
+		return -ENOMEM;	/* failure, out of memory */
+	/* init port data */
+	new_port->addr.client = client->number;
+	new_port->addr.port = -1;
+	new_port->owner = THIS_MODULE;
+	snd_use_lock_init(&new_port->use_lock);
+	port_subs_info_init(&new_port->c_src);
+	port_subs_info_init(&new_port->c_dest);
+	snd_use_lock_use(&new_port->use_lock);
+
+	num = max(port, 0);
+	mutex_lock(&client->ports_mutex);
+	write_lock_irq(&client->ports_lock);
+	list_for_each_entry(p, &client->ports_list_head, list) {
+		if (p->addr.port == port) {
+			kfree(new_port);
+			num = -EBUSY;
+			goto unlock;
+		}
+		if (p->addr.port > num)
+			break;
+		if (port < 0) /* auto-probe mode */
+			num = p->addr.port + 1;
+	}
+	/* insert the new port */
+	list_add_tail(&new_port->list, &p->list);
+	client->num_ports++;
+	new_port->addr.port = num;	/* store the port number in the port */
+	sprintf(new_port->name, "port-%d", num);
+	*port_ret = new_port;
+ unlock:
+	write_unlock_irq(&client->ports_lock);
+	mutex_unlock(&client->ports_mutex);
+
+	return num;
+}
+
+/* */
+static int subscribe_port(struct snd_seq_client *client,
+			  struct snd_seq_client_port *port,
+			  struct snd_seq_port_subs_info *grp,
+			  struct snd_seq_port_subscribe *info, int send_ack);
+static int unsubscribe_port(struct snd_seq_client *client,
+			    struct snd_seq_client_port *port,
+			    struct snd_seq_port_subs_info *grp,
+			    struct snd_seq_port_subscribe *info, int send_ack);
+
+
+static struct snd_seq_client_port *get_client_port(struct snd_seq_addr *addr,
+						   struct snd_seq_client **cp)
+{
+	struct snd_seq_client_port *p;
+	*cp = snd_seq_client_use_ptr(addr->client);
+	if (*cp) {
+		p = snd_seq_port_use_ptr(*cp, addr->port);
+		if (! p) {
+			snd_seq_client_unlock(*cp);
+			*cp = NULL;
+		}
+		return p;
+	}
+	return NULL;
+}
+
+static void delete_and_unsubscribe_port(struct snd_seq_client *client,
+					struct snd_seq_client_port *port,
+					struct snd_seq_subscribers *subs,
+					bool is_src, bool ack);
+
+static inline struct snd_seq_subscribers *
+get_subscriber(struct list_head *p, bool is_src)
+{
+	if (is_src)
+		return list_entry(p, struct snd_seq_subscribers, src_list);
+	else
+		return list_entry(p, struct snd_seq_subscribers, dest_list);
+}
+
+/*
+ * remove all subscribers on the list
+ * this is called from port_delete, for each src and dest list.
+ */
+static void clear_subscriber_list(struct snd_seq_client *client,
+				  struct snd_seq_client_port *port,
+				  struct snd_seq_port_subs_info *grp,
+				  int is_src)
+{
+	struct list_head *p, *n;
+
+	list_for_each_safe(p, n, &grp->list_head) {
+		struct snd_seq_subscribers *subs;
+		struct snd_seq_client *c;
+		struct snd_seq_client_port *aport;
+
+		subs = get_subscriber(p, is_src);
+		if (is_src)
+			aport = get_client_port(&subs->info.dest, &c);
+		else
+			aport = get_client_port(&subs->info.sender, &c);
+		delete_and_unsubscribe_port(client, port, subs, is_src, false);
+
+		if (!aport) {
+			/* looks like the connected port is being deleted.
+			 * we decrease the counter, and when both ports are deleted
+			 * remove the subscriber info
+			 */
+			if (atomic_dec_and_test(&subs->ref_count))
+				kfree(subs);
+			continue;
+		}
+
+		/* ok we got the connected port */
+		delete_and_unsubscribe_port(c, aport, subs, !is_src, true);
+		kfree(subs);
+		snd_seq_port_unlock(aport);
+		snd_seq_client_unlock(c);
+	}
+}
+
+/* delete port data */
+static int port_delete(struct snd_seq_client *client,
+		       struct snd_seq_client_port *port)
+{
+	/* set closing flag and wait for all port access are gone */
+	port->closing = 1;
+	snd_use_lock_sync(&port->use_lock); 
+
+	/* clear subscribers info */
+	clear_subscriber_list(client, port, &port->c_src, true);
+	clear_subscriber_list(client, port, &port->c_dest, false);
+
+	if (port->private_free)
+		port->private_free(port->private_data);
+
+	snd_BUG_ON(port->c_src.count != 0);
+	snd_BUG_ON(port->c_dest.count != 0);
+
+	kfree(port);
+	return 0;
+}
+
+
+/* delete a port with the given port id */
+int snd_seq_delete_port(struct snd_seq_client *client, int port)
+{
+	struct snd_seq_client_port *found = NULL, *p;
+
+	mutex_lock(&client->ports_mutex);
+	write_lock_irq(&client->ports_lock);
+	list_for_each_entry(p, &client->ports_list_head, list) {
+		if (p->addr.port == port) {
+			/* ok found.  delete from the list at first */
+			list_del(&p->list);
+			client->num_ports--;
+			found = p;
+			break;
+		}
+	}
+	write_unlock_irq(&client->ports_lock);
+	mutex_unlock(&client->ports_mutex);
+	if (found)
+		return port_delete(client, found);
+	else
+		return -ENOENT;
+}
+
+/* delete the all ports belonging to the given client */
+int snd_seq_delete_all_ports(struct snd_seq_client *client)
+{
+	struct list_head deleted_list;
+	struct snd_seq_client_port *port, *tmp;
+	
+	/* move the port list to deleted_list, and
+	 * clear the port list in the client data.
+	 */
+	mutex_lock(&client->ports_mutex);
+	write_lock_irq(&client->ports_lock);
+	if (! list_empty(&client->ports_list_head)) {
+		list_add(&deleted_list, &client->ports_list_head);
+		list_del_init(&client->ports_list_head);
+	} else {
+		INIT_LIST_HEAD(&deleted_list);
+	}
+	client->num_ports = 0;
+	write_unlock_irq(&client->ports_lock);
+
+	/* remove each port in deleted_list */
+	list_for_each_entry_safe(port, tmp, &deleted_list, list) {
+		list_del(&port->list);
+		snd_seq_system_client_ev_port_exit(port->addr.client, port->addr.port);
+		port_delete(client, port);
+	}
+	mutex_unlock(&client->ports_mutex);
+	return 0;
+}
+
+/* set port info fields */
+int snd_seq_set_port_info(struct snd_seq_client_port * port,
+			  struct snd_seq_port_info * info)
+{
+	if (snd_BUG_ON(!port || !info))
+		return -EINVAL;
+
+	/* set port name */
+	if (info->name[0])
+		strscpy(port->name, info->name, sizeof(port->name));
+	
+	/* set capabilities */
+	port->capability = info->capability;
+	
+	/* get port type */
+	port->type = info->type;
+
+	/* information about supported channels/voices */
+	port->midi_channels = info->midi_channels;
+	port->midi_voices = info->midi_voices;
+	port->synth_voices = info->synth_voices;
+
+	/* timestamping */
+	port->timestamping = (info->flags & SNDRV_SEQ_PORT_FLG_TIMESTAMP) ? 1 : 0;
+	port->time_real = (info->flags & SNDRV_SEQ_PORT_FLG_TIME_REAL) ? 1 : 0;
+	port->time_queue = info->time_queue;
+
+	/* UMP direction and group */
+	port->direction = info->direction;
+	port->ump_group = info->ump_group;
+	if (port->ump_group > SNDRV_UMP_MAX_GROUPS)
+		port->ump_group = 0;
+
+	/* fill default port direction */
+	if (!port->direction) {
+		if (info->capability & SNDRV_SEQ_PORT_CAP_READ)
+			port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+		if (info->capability & SNDRV_SEQ_PORT_CAP_WRITE)
+			port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
+	}
+
+	return 0;
+}
+
+/* get port info fields */
+int snd_seq_get_port_info(struct snd_seq_client_port * port,
+			  struct snd_seq_port_info * info)
+{
+	if (snd_BUG_ON(!port || !info))
+		return -EINVAL;
+
+	/* get port name */
+	strscpy(info->name, port->name, sizeof(info->name));
+	
+	/* get capabilities */
+	info->capability = port->capability;
+
+	/* get port type */
+	info->type = port->type;
+
+	/* information about supported channels/voices */
+	info->midi_channels = port->midi_channels;
+	info->midi_voices = port->midi_voices;
+	info->synth_voices = port->synth_voices;
+
+	/* get subscriber counts */
+	info->read_use = port->c_src.count;
+	info->write_use = port->c_dest.count;
+	
+	/* timestamping */
+	info->flags = 0;
+	if (port->timestamping) {
+		info->flags |= SNDRV_SEQ_PORT_FLG_TIMESTAMP;
+		if (port->time_real)
+			info->flags |= SNDRV_SEQ_PORT_FLG_TIME_REAL;
+		info->time_queue = port->time_queue;
+	}
+
+	/* UMP direction and group */
+	info->direction = port->direction;
+	info->ump_group = port->ump_group;
+
+	return 0;
+}
+
+
+
+/*
+ * call callback functions (if any):
+ * the callbacks are invoked only when the first (for connection) or
+ * the last subscription (for disconnection) is done.  Second or later
+ * subscription results in increment of counter, but no callback is
+ * invoked.
+ * This feature is useful if these callbacks are associated with
+ * initialization or termination of devices (see seq_midi.c).
+ */
+
+static int subscribe_port(struct snd_seq_client *client,
+			  struct snd_seq_client_port *port,
+			  struct snd_seq_port_subs_info *grp,
+			  struct snd_seq_port_subscribe *info,
+			  int send_ack)
+{
+	int err = 0;
+
+	if (!try_module_get(port->owner))
+		return -EFAULT;
+	grp->count++;
+	if (grp->open && grp->count == 1) {
+		err = grp->open(port->private_data, info);
+		if (err < 0) {
+			module_put(port->owner);
+			grp->count--;
+		}
+	}
+	if (err >= 0 && send_ack && client->type == USER_CLIENT)
+		snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
+						   info, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
+
+	return err;
+}
+
+static int unsubscribe_port(struct snd_seq_client *client,
+			    struct snd_seq_client_port *port,
+			    struct snd_seq_port_subs_info *grp,
+			    struct snd_seq_port_subscribe *info,
+			    int send_ack)
+{
+	int err = 0;
+
+	if (! grp->count)
+		return -EINVAL;
+	grp->count--;
+	if (grp->close && grp->count == 0)
+		err = grp->close(port->private_data, info);
+	if (send_ack && client->type == USER_CLIENT)
+		snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
+						   info, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
+	module_put(port->owner);
+	return err;
+}
+
+
+
+/* check if both addresses are identical */
+static inline int addr_match(struct snd_seq_addr *r, struct snd_seq_addr *s)
+{
+	return (r->client == s->client) && (r->port == s->port);
+}
+
+/* check the two subscribe info match */
+/* if flags is zero, checks only sender and destination addresses */
+static int match_subs_info(struct snd_seq_port_subscribe *r,
+			   struct snd_seq_port_subscribe *s)
+{
+	if (addr_match(&r->sender, &s->sender) &&
+	    addr_match(&r->dest, &s->dest)) {
+		if (r->flags && r->flags == s->flags)
+			return r->queue == s->queue;
+		else if (! r->flags)
+			return 1;
+	}
+	return 0;
+}
+
+static int check_and_subscribe_port(struct snd_seq_client *client,
+				    struct snd_seq_client_port *port,
+				    struct snd_seq_subscribers *subs,
+				    bool is_src, bool exclusive, bool ack)
+{
+	struct snd_seq_port_subs_info *grp;
+	struct list_head *p;
+	struct snd_seq_subscribers *s;
+	int err;
+
+	grp = is_src ? &port->c_src : &port->c_dest;
+	err = -EBUSY;
+	down_write(&grp->list_mutex);
+	if (exclusive) {
+		if (!list_empty(&grp->list_head))
+			goto __error;
+	} else {
+		if (grp->exclusive)
+			goto __error;
+		/* check whether already exists */
+		list_for_each(p, &grp->list_head) {
+			s = get_subscriber(p, is_src);
+			if (match_subs_info(&subs->info, &s->info))
+				goto __error;
+		}
+	}
+
+	err = subscribe_port(client, port, grp, &subs->info, ack);
+	if (err < 0) {
+		grp->exclusive = 0;
+		goto __error;
+	}
+
+	/* add to list */
+	write_lock_irq(&grp->list_lock);
+	if (is_src)
+		list_add_tail(&subs->src_list, &grp->list_head);
+	else
+		list_add_tail(&subs->dest_list, &grp->list_head);
+	grp->exclusive = exclusive;
+	atomic_inc(&subs->ref_count);
+	write_unlock_irq(&grp->list_lock);
+	err = 0;
+
+ __error:
+	up_write(&grp->list_mutex);
+	return err;
+}
+
+/* called with grp->list_mutex held */
+static void __delete_and_unsubscribe_port(struct snd_seq_client *client,
+					  struct snd_seq_client_port *port,
+					  struct snd_seq_subscribers *subs,
+					  bool is_src, bool ack)
+{
+	struct snd_seq_port_subs_info *grp;
+	struct list_head *list;
+	bool empty;
+
+	grp = is_src ? &port->c_src : &port->c_dest;
+	list = is_src ? &subs->src_list : &subs->dest_list;
+	write_lock_irq(&grp->list_lock);
+	empty = list_empty(list);
+	if (!empty)
+		list_del_init(list);
+	grp->exclusive = 0;
+	write_unlock_irq(&grp->list_lock);
+
+	if (!empty)
+		unsubscribe_port(client, port, grp, &subs->info, ack);
+}
+
+static void delete_and_unsubscribe_port(struct snd_seq_client *client,
+					struct snd_seq_client_port *port,
+					struct snd_seq_subscribers *subs,
+					bool is_src, bool ack)
+{
+	struct snd_seq_port_subs_info *grp;
+
+	grp = is_src ? &port->c_src : &port->c_dest;
+	down_write(&grp->list_mutex);
+	__delete_and_unsubscribe_port(client, port, subs, is_src, ack);
+	up_write(&grp->list_mutex);
+}
+
+/* connect two ports */
+int snd_seq_port_connect(struct snd_seq_client *connector,
+			 struct snd_seq_client *src_client,
+			 struct snd_seq_client_port *src_port,
+			 struct snd_seq_client *dest_client,
+			 struct snd_seq_client_port *dest_port,
+			 struct snd_seq_port_subscribe *info)
+{
+	struct snd_seq_subscribers *subs;
+	bool exclusive;
+	int err;
+
+	subs = kzalloc(sizeof(*subs), GFP_KERNEL);
+	if (!subs)
+		return -ENOMEM;
+
+	subs->info = *info;
+	atomic_set(&subs->ref_count, 0);
+	INIT_LIST_HEAD(&subs->src_list);
+	INIT_LIST_HEAD(&subs->dest_list);
+
+	exclusive = !!(info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE);
+
+	err = check_and_subscribe_port(src_client, src_port, subs, true,
+				       exclusive,
+				       connector->number != src_client->number);
+	if (err < 0)
+		goto error;
+	err = check_and_subscribe_port(dest_client, dest_port, subs, false,
+				       exclusive,
+				       connector->number != dest_client->number);
+	if (err < 0)
+		goto error_dest;
+
+	return 0;
+
+ error_dest:
+	delete_and_unsubscribe_port(src_client, src_port, subs, true,
+				    connector->number != src_client->number);
+ error:
+	kfree(subs);
+	return err;
+}
+
+/* remove the connection */
+int snd_seq_port_disconnect(struct snd_seq_client *connector,
+			    struct snd_seq_client *src_client,
+			    struct snd_seq_client_port *src_port,
+			    struct snd_seq_client *dest_client,
+			    struct snd_seq_client_port *dest_port,
+			    struct snd_seq_port_subscribe *info)
+{
+	struct snd_seq_port_subs_info *dest = &dest_port->c_dest;
+	struct snd_seq_subscribers *subs;
+	int err = -ENOENT;
+
+	/* always start from deleting the dest port for avoiding concurrent
+	 * deletions
+	 */
+	down_write(&dest->list_mutex);
+	/* look for the connection */
+	list_for_each_entry(subs, &dest->list_head, dest_list) {
+		if (match_subs_info(info, &subs->info)) {
+			__delete_and_unsubscribe_port(dest_client, dest_port,
+						      subs, false,
+						      connector->number != dest_client->number);
+			err = 0;
+			break;
+		}
+	}
+	up_write(&dest->list_mutex);
+	if (err < 0)
+		return err;
+
+	delete_and_unsubscribe_port(src_client, src_port, subs, true,
+				    connector->number != src_client->number);
+	kfree(subs);
+	return 0;
+}
+
+
+/* get matched subscriber */
+int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
+				  struct snd_seq_addr *dest_addr,
+				  struct snd_seq_port_subscribe *subs)
+{
+	struct snd_seq_subscribers *s;
+	int err = -ENOENT;
+
+	down_read(&src_grp->list_mutex);
+	list_for_each_entry(s, &src_grp->list_head, src_list) {
+		if (addr_match(dest_addr, &s->info.dest)) {
+			*subs = s->info;
+			err = 0;
+			break;
+		}
+	}
+	up_read(&src_grp->list_mutex);
+	return err;
+}
+
+/*
+ * Attach a device driver that wants to receive events from the
+ * sequencer.  Returns the new port number on success.
+ * A driver that wants to receive the events converted to midi, will
+ * use snd_seq_midisynth_register_port().
+ */
+/* exported */
+int snd_seq_event_port_attach(int client,
+			      struct snd_seq_port_callback *pcbp,
+			      int cap, int type, int midi_channels,
+			      int midi_voices, char *portname)
+{
+	struct snd_seq_port_info portinfo;
+	int  ret;
+
+	/* Set up the port */
+	memset(&portinfo, 0, sizeof(portinfo));
+	portinfo.addr.client = client;
+	strscpy(portinfo.name, portname ? portname : "Unnamed port",
+		sizeof(portinfo.name));
+
+	portinfo.capability = cap;
+	portinfo.type = type;
+	portinfo.kernel = pcbp;
+	portinfo.midi_channels = midi_channels;
+	portinfo.midi_voices = midi_voices;
+
+	/* Create it */
+	ret = snd_seq_kernel_client_ctl(client,
+					SNDRV_SEQ_IOCTL_CREATE_PORT,
+					&portinfo);
+
+	if (ret >= 0)
+		ret = portinfo.addr.port;
+
+	return ret;
+}
+EXPORT_SYMBOL(snd_seq_event_port_attach);
+
+/*
+ * Detach the driver from a port.
+ */
+/* exported */
+int snd_seq_event_port_detach(int client, int port)
+{
+	struct snd_seq_port_info portinfo;
+	int  err;
+
+	memset(&portinfo, 0, sizeof(portinfo));
+	portinfo.addr.client = client;
+	portinfo.addr.port   = port;
+	err = snd_seq_kernel_client_ctl(client,
+					SNDRV_SEQ_IOCTL_DELETE_PORT,
+					&portinfo);
+
+	return err;
+}
+EXPORT_SYMBOL(snd_seq_event_port_detach);
diff --git a/sound/core/seq/seq_ports.h b/sound/core/seq/seq_ports.h
new file mode 100644
index 0000000000..b111382f69
--- /dev/null
+++ b/sound/core/seq/seq_ports.h
@@ -0,0 +1,146 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer Ports 
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_PORTS_H
+#define __SND_SEQ_PORTS_H
+
+#include <sound/seq_kernel.h>
+#include "seq_lock.h"
+
+/* list of 'exported' ports */
+
+/* Client ports that are not exported are still accessible, but are
+ anonymous ports. 
+ 
+ If a port supports SUBSCRIPTION, that port can send events to all
+ subscribersto a special address, with address
+ (queue==SNDRV_SEQ_ADDRESS_SUBSCRIBERS). The message is then send to all
+ recipients that are registered in the subscription list. A typical
+ application for these SUBSCRIPTION events is handling of incoming MIDI
+ data. The port doesn't 'know' what other clients are interested in this
+ message. If for instance a MIDI recording application would like to receive
+ the events from that port, it will first have to subscribe with that port.
+ 
+*/
+
+struct snd_seq_subscribers {
+	struct snd_seq_port_subscribe info;	/* additional info */
+	struct list_head src_list;	/* link of sources */
+	struct list_head dest_list;	/* link of destinations */
+	atomic_t ref_count;
+};
+
+struct snd_seq_port_subs_info {
+	struct list_head list_head;	/* list of subscribed ports */
+	unsigned int count;		/* count of subscribers */
+	unsigned int exclusive: 1;	/* exclusive mode */
+	struct rw_semaphore list_mutex;
+	rwlock_t list_lock;
+	int (*open)(void *private_data, struct snd_seq_port_subscribe *info);
+	int (*close)(void *private_data, struct snd_seq_port_subscribe *info);
+};
+
+/* context for converting from legacy control event to UMP packet */
+struct snd_seq_ump_midi2_bank {
+	bool rpn_set;
+	bool nrpn_set;
+	bool bank_set;
+	unsigned char cc_rpn_msb, cc_rpn_lsb;
+	unsigned char cc_nrpn_msb, cc_nrpn_lsb;
+	unsigned char cc_data_msb, cc_data_lsb;
+	unsigned char cc_bank_msb, cc_bank_lsb;
+};
+
+struct snd_seq_client_port {
+
+	struct snd_seq_addr addr;	/* client/port number */
+	struct module *owner;		/* owner of this port */
+	char name[64];			/* port name */	
+	struct list_head list;		/* port list */
+	snd_use_lock_t use_lock;
+
+	/* subscribers */
+	struct snd_seq_port_subs_info c_src;	/* read (sender) list */
+	struct snd_seq_port_subs_info c_dest;	/* write (dest) list */
+
+	int (*event_input)(struct snd_seq_event *ev, int direct, void *private_data,
+			   int atomic, int hop);
+	void (*private_free)(void *private_data);
+	void *private_data;
+	unsigned int closing : 1;
+	unsigned int timestamping: 1;
+	unsigned int time_real: 1;
+	int time_queue;
+	
+	/* capability, inport, output, sync */
+	unsigned int capability;	/* port capability bits */
+	unsigned int type;		/* port type bits */
+
+	/* supported channels */
+	int midi_channels;
+	int midi_voices;
+	int synth_voices;
+		
+	/* UMP direction and group */
+	unsigned char direction;
+	unsigned char ump_group;
+
+#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
+	struct snd_seq_ump_midi2_bank midi2_bank[16]; /* per channel */
+#endif
+};
+
+struct snd_seq_client;
+
+/* return pointer to port structure and lock port */
+struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client, int num);
+
+/* search for next port - port is locked if found */
+struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
+						       struct snd_seq_port_info *pinfo);
+
+/* unlock the port */
+#define snd_seq_port_unlock(port) snd_use_lock_free(&(port)->use_lock)
+
+/* create a port, port number or a negative error code is returned */
+int snd_seq_create_port(struct snd_seq_client *client, int port_index,
+			struct snd_seq_client_port **port_ret);
+
+/* delete a port */
+int snd_seq_delete_port(struct snd_seq_client *client, int port);
+
+/* delete all ports */
+int snd_seq_delete_all_ports(struct snd_seq_client *client);
+
+/* set port info fields */
+int snd_seq_set_port_info(struct snd_seq_client_port *port,
+			  struct snd_seq_port_info *info);
+
+/* get port info fields */
+int snd_seq_get_port_info(struct snd_seq_client_port *port,
+			  struct snd_seq_port_info *info);
+
+/* add subscriber to subscription list */
+int snd_seq_port_connect(struct snd_seq_client *caller,
+			 struct snd_seq_client *s, struct snd_seq_client_port *sp,
+			 struct snd_seq_client *d, struct snd_seq_client_port *dp,
+			 struct snd_seq_port_subscribe *info);
+
+/* remove subscriber from subscription list */ 
+int snd_seq_port_disconnect(struct snd_seq_client *caller,
+			    struct snd_seq_client *s, struct snd_seq_client_port *sp,
+			    struct snd_seq_client *d, struct snd_seq_client_port *dp,
+			    struct snd_seq_port_subscribe *info);
+
+/* subscribe port */
+int snd_seq_port_subscribe(struct snd_seq_client_port *port,
+			   struct snd_seq_port_subscribe *info);
+
+/* get matched subscriber */
+int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
+				  struct snd_seq_addr *dest_addr,
+				  struct snd_seq_port_subscribe *subs);
+
+#endif
diff --git a/sound/core/seq/seq_prioq.c b/sound/core/seq/seq_prioq.c
new file mode 100644
index 0000000000..1d857981e8
--- /dev/null
+++ b/sound/core/seq/seq_prioq.c
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer Priority Queue
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include "seq_timer.h"
+#include "seq_prioq.h"
+
+
+/* Implementation is a simple linked list for now...
+
+   This priority queue orders the events on timestamp. For events with an
+   equeal timestamp the queue behaves as a FIFO. 
+
+   *
+   *           +-------+
+   *  Head --> | first |
+   *           +-------+
+   *                 |next
+   *           +-----v-+
+   *           |       |
+   *           +-------+
+   *                 |
+   *           +-----v-+
+   *           |       |
+   *           +-------+
+   *                 |
+   *           +-----v-+
+   *  Tail --> | last  |
+   *           +-------+
+   *
+
+ */
+
+
+
+/* create new prioq (constructor) */
+struct snd_seq_prioq *snd_seq_prioq_new(void)
+{
+	struct snd_seq_prioq *f;
+
+	f = kzalloc(sizeof(*f), GFP_KERNEL);
+	if (!f)
+		return NULL;
+	
+	spin_lock_init(&f->lock);
+	f->head = NULL;
+	f->tail = NULL;
+	f->cells = 0;
+	
+	return f;
+}
+
+/* delete prioq (destructor) */
+void snd_seq_prioq_delete(struct snd_seq_prioq **fifo)
+{
+	struct snd_seq_prioq *f = *fifo;
+	*fifo = NULL;
+
+	if (f == NULL) {
+		pr_debug("ALSA: seq: snd_seq_prioq_delete() called with NULL prioq\n");
+		return;
+	}
+
+	/* release resources...*/
+	/*....................*/
+	
+	if (f->cells > 0) {
+		/* drain prioQ */
+		while (f->cells > 0)
+			snd_seq_cell_free(snd_seq_prioq_cell_out(f, NULL));
+	}
+	
+	kfree(f);
+}
+
+
+
+
+/* compare timestamp between events */
+/* return 1 if a >= b; 0 */
+static inline int compare_timestamp(struct snd_seq_event *a,
+				    struct snd_seq_event *b)
+{
+	if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
+		/* compare ticks */
+		return (snd_seq_compare_tick_time(&a->time.tick, &b->time.tick));
+	} else {
+		/* compare real time */
+		return (snd_seq_compare_real_time(&a->time.time, &b->time.time));
+	}
+}
+
+/* compare timestamp between events */
+/* return negative if a < b;
+ *        zero     if a = b;
+ *        positive if a > b;
+ */
+static inline int compare_timestamp_rel(struct snd_seq_event *a,
+					struct snd_seq_event *b)
+{
+	if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
+		/* compare ticks */
+		if (a->time.tick > b->time.tick)
+			return 1;
+		else if (a->time.tick == b->time.tick)
+			return 0;
+		else
+			return -1;
+	} else {
+		/* compare real time */
+		if (a->time.time.tv_sec > b->time.time.tv_sec)
+			return 1;
+		else if (a->time.time.tv_sec == b->time.time.tv_sec) {
+			if (a->time.time.tv_nsec > b->time.time.tv_nsec)
+				return 1;
+			else if (a->time.time.tv_nsec == b->time.time.tv_nsec)
+				return 0;
+			else
+				return -1;
+		} else
+			return -1;
+	}
+}
+
+/* enqueue cell to prioq */
+int snd_seq_prioq_cell_in(struct snd_seq_prioq * f,
+			  struct snd_seq_event_cell * cell)
+{
+	struct snd_seq_event_cell *cur, *prev;
+	unsigned long flags;
+	int count;
+	int prior;
+
+	if (snd_BUG_ON(!f || !cell))
+		return -EINVAL;
+	
+	/* check flags */
+	prior = (cell->event.flags & SNDRV_SEQ_PRIORITY_MASK);
+
+	spin_lock_irqsave(&f->lock, flags);
+
+	/* check if this element needs to inserted at the end (ie. ordered 
+	   data is inserted) This will be very likeley if a sequencer 
+	   application or midi file player is feeding us (sequential) data */
+	if (f->tail && !prior) {
+		if (compare_timestamp(&cell->event, &f->tail->event)) {
+			/* add new cell to tail of the fifo */
+			f->tail->next = cell;
+			f->tail = cell;
+			cell->next = NULL;
+			f->cells++;
+			spin_unlock_irqrestore(&f->lock, flags);
+			return 0;
+		}
+	}
+	/* traverse list of elements to find the place where the new cell is
+	   to be inserted... Note that this is a order n process ! */
+
+	prev = NULL;		/* previous cell */
+	cur = f->head;		/* cursor */
+
+	count = 10000; /* FIXME: enough big, isn't it? */
+	while (cur != NULL) {
+		/* compare timestamps */
+		int rel = compare_timestamp_rel(&cell->event, &cur->event);
+		if (rel < 0)
+			/* new cell has earlier schedule time, */
+			break;
+		else if (rel == 0 && prior)
+			/* equal schedule time and prior to others */
+			break;
+		/* new cell has equal or larger schedule time, */
+		/* move cursor to next cell */
+		prev = cur;
+		cur = cur->next;
+		if (! --count) {
+			spin_unlock_irqrestore(&f->lock, flags);
+			pr_err("ALSA: seq: cannot find a pointer.. infinite loop?\n");
+			return -EINVAL;
+		}
+	}
+
+	/* insert it before cursor */
+	if (prev != NULL)
+		prev->next = cell;
+	cell->next = cur;
+
+	if (f->head == cur) /* this is the first cell, set head to it */
+		f->head = cell;
+	if (cur == NULL) /* reached end of the list */
+		f->tail = cell;
+	f->cells++;
+	spin_unlock_irqrestore(&f->lock, flags);
+	return 0;
+}
+
+/* return 1 if the current time >= event timestamp */
+static int event_is_ready(struct snd_seq_event *ev, void *current_time)
+{
+	if ((ev->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK)
+		return snd_seq_compare_tick_time(current_time, &ev->time.tick);
+	else
+		return snd_seq_compare_real_time(current_time, &ev->time.time);
+}
+
+/* dequeue cell from prioq */
+struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f,
+						  void *current_time)
+{
+	struct snd_seq_event_cell *cell;
+	unsigned long flags;
+
+	if (f == NULL) {
+		pr_debug("ALSA: seq: snd_seq_prioq_cell_in() called with NULL prioq\n");
+		return NULL;
+	}
+	spin_lock_irqsave(&f->lock, flags);
+
+	cell = f->head;
+	if (cell && current_time && !event_is_ready(&cell->event, current_time))
+		cell = NULL;
+	if (cell) {
+		f->head = cell->next;
+
+		/* reset tail if this was the last element */
+		if (f->tail == cell)
+			f->tail = NULL;
+
+		cell->next = NULL;
+		f->cells--;
+	}
+
+	spin_unlock_irqrestore(&f->lock, flags);
+	return cell;
+}
+
+/* return number of events available in prioq */
+int snd_seq_prioq_avail(struct snd_seq_prioq * f)
+{
+	if (f == NULL) {
+		pr_debug("ALSA: seq: snd_seq_prioq_cell_in() called with NULL prioq\n");
+		return 0;
+	}
+	return f->cells;
+}
+
+static inline int prioq_match(struct snd_seq_event_cell *cell,
+			      int client, int timestamp)
+{
+	if (cell->event.source.client == client ||
+	    cell->event.dest.client == client)
+		return 1;
+	if (!timestamp)
+		return 0;
+	switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
+	case SNDRV_SEQ_TIME_STAMP_TICK:
+		if (cell->event.time.tick)
+			return 1;
+		break;
+	case SNDRV_SEQ_TIME_STAMP_REAL:
+		if (cell->event.time.time.tv_sec ||
+		    cell->event.time.time.tv_nsec)
+			return 1;
+		break;
+	}
+	return 0;
+}
+
+/* remove cells for left client */
+void snd_seq_prioq_leave(struct snd_seq_prioq * f, int client, int timestamp)
+{
+	register struct snd_seq_event_cell *cell, *next;
+	unsigned long flags;
+	struct snd_seq_event_cell *prev = NULL;
+	struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
+
+	/* collect all removed cells */
+	spin_lock_irqsave(&f->lock, flags);
+	cell = f->head;
+	while (cell) {
+		next = cell->next;
+		if (prioq_match(cell, client, timestamp)) {
+			/* remove cell from prioq */
+			if (cell == f->head) {
+				f->head = cell->next;
+			} else {
+				prev->next = cell->next;
+			}
+			if (cell == f->tail)
+				f->tail = cell->next;
+			f->cells--;
+			/* add cell to free list */
+			cell->next = NULL;
+			if (freefirst == NULL) {
+				freefirst = cell;
+			} else {
+				freeprev->next = cell;
+			}
+			freeprev = cell;
+		} else {
+#if 0
+			pr_debug("ALSA: seq: type = %i, source = %i, dest = %i, "
+			       "client = %i\n",
+				cell->event.type,
+				cell->event.source.client,
+				cell->event.dest.client,
+				client);
+#endif
+			prev = cell;
+		}
+		cell = next;		
+	}
+	spin_unlock_irqrestore(&f->lock, flags);	
+
+	/* remove selected cells */
+	while (freefirst) {
+		freenext = freefirst->next;
+		snd_seq_cell_free(freefirst);
+		freefirst = freenext;
+	}
+}
+
+static int prioq_remove_match(struct snd_seq_remove_events *info,
+			      struct snd_seq_event *ev)
+{
+	int res;
+
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) {
+		if (ev->dest.client != info->dest.client ||
+				ev->dest.port != info->dest.port)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST_CHANNEL) {
+		if (! snd_seq_ev_is_channel_type(ev))
+			return 0;
+		/* data.note.channel and data.control.channel are identical */
+		if (ev->data.note.channel != info->channel)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_AFTER) {
+		if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK)
+			res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick);
+		else
+			res = snd_seq_compare_real_time(&ev->time.time, &info->time.time);
+		if (!res)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_BEFORE) {
+		if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK)
+			res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick);
+		else
+			res = snd_seq_compare_real_time(&ev->time.time, &info->time.time);
+		if (res)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_EVENT_TYPE) {
+		if (ev->type != info->type)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_IGNORE_OFF) {
+		/* Do not remove off events */
+		switch (ev->type) {
+		case SNDRV_SEQ_EVENT_NOTEOFF:
+		/* case SNDRV_SEQ_EVENT_SAMPLE_STOP: */
+			return 0;
+		default:
+			break;
+		}
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_TAG_MATCH) {
+		if (info->tag != ev->tag)
+			return 0;
+	}
+
+	return 1;
+}
+
+/* remove cells matching remove criteria */
+void snd_seq_prioq_remove_events(struct snd_seq_prioq * f, int client,
+				 struct snd_seq_remove_events *info)
+{
+	struct snd_seq_event_cell *cell, *next;
+	unsigned long flags;
+	struct snd_seq_event_cell *prev = NULL;
+	struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
+
+	/* collect all removed cells */
+	spin_lock_irqsave(&f->lock, flags);
+	cell = f->head;
+
+	while (cell) {
+		next = cell->next;
+		if (cell->event.source.client == client &&
+			prioq_remove_match(info, &cell->event)) {
+
+			/* remove cell from prioq */
+			if (cell == f->head) {
+				f->head = cell->next;
+			} else {
+				prev->next = cell->next;
+			}
+
+			if (cell == f->tail)
+				f->tail = cell->next;
+			f->cells--;
+
+			/* add cell to free list */
+			cell->next = NULL;
+			if (freefirst == NULL) {
+				freefirst = cell;
+			} else {
+				freeprev->next = cell;
+			}
+
+			freeprev = cell;
+		} else {
+			prev = cell;
+		}
+		cell = next;		
+	}
+	spin_unlock_irqrestore(&f->lock, flags);	
+
+	/* remove selected cells */
+	while (freefirst) {
+		freenext = freefirst->next;
+		snd_seq_cell_free(freefirst);
+		freefirst = freenext;
+	}
+}
+
+
diff --git a/sound/core/seq/seq_prioq.h b/sound/core/seq/seq_prioq.h
new file mode 100644
index 0000000000..5811a87deb
--- /dev/null
+++ b/sound/core/seq/seq_prioq.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer Priority Queue
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_PRIOQ_H
+#define __SND_SEQ_PRIOQ_H
+
+#include "seq_memory.h"
+
+
+/* === PRIOQ === */
+
+struct snd_seq_prioq {
+	struct snd_seq_event_cell *head;      /* pointer to head of prioq */
+	struct snd_seq_event_cell *tail;      /* pointer to tail of prioq */
+	int cells;
+	spinlock_t lock;
+};
+
+
+/* create new prioq (constructor) */
+struct snd_seq_prioq *snd_seq_prioq_new(void);
+
+/* delete prioq (destructor) */
+void snd_seq_prioq_delete(struct snd_seq_prioq **fifo);
+
+/* enqueue cell to prioq */
+int snd_seq_prioq_cell_in(struct snd_seq_prioq *f, struct snd_seq_event_cell *cell);
+
+/* dequeue cell from prioq */ 
+struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f,
+						  void *current_time);
+
+/* return number of events available in prioq */
+int snd_seq_prioq_avail(struct snd_seq_prioq *f);
+
+/* client left queue */
+void snd_seq_prioq_leave(struct snd_seq_prioq *f, int client, int timestamp);        
+
+/* Remove events */
+void snd_seq_prioq_remove_events(struct snd_seq_prioq *f, int client,
+				 struct snd_seq_remove_events *info);
+
+#endif
diff --git a/sound/core/seq/seq_queue.c b/sound/core/seq/seq_queue.c
new file mode 100644
index 0000000000..bc933104c3
--- /dev/null
+++ b/sound/core/seq/seq_queue.c
@@ -0,0 +1,774 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer Timing queue handling
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *
+ * MAJOR CHANGES
+ *   Nov. 13, 1999	Takashi Iwai <iwai@ww.uni-erlangen.de>
+ *     - Queues are allocated dynamically via ioctl.
+ *     - When owner client is deleted, all owned queues are deleted, too.
+ *     - Owner of unlocked queue is kept unmodified even if it is
+ *	 manipulated by other clients.
+ *     - Owner field in SET_QUEUE_OWNER ioctl must be identical with the
+ *       caller client.  i.e. Changing owner to a third client is not
+ *       allowed.
+ *
+ *  Aug. 30, 2000	Takashi Iwai
+ *     - Queues are managed in static array again, but with better way.
+ *       The API itself is identical.
+ *     - The queue is locked when struct snd_seq_queue pointer is returned via
+ *       queueptr().  This pointer *MUST* be released afterward by
+ *       queuefree(ptr).
+ *     - Addition of experimental sync support.
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+
+#include "seq_memory.h"
+#include "seq_queue.h"
+#include "seq_clientmgr.h"
+#include "seq_fifo.h"
+#include "seq_timer.h"
+#include "seq_info.h"
+
+/* list of allocated queues */
+static struct snd_seq_queue *queue_list[SNDRV_SEQ_MAX_QUEUES];
+static DEFINE_SPINLOCK(queue_list_lock);
+/* number of queues allocated */
+static int num_queues;
+
+int snd_seq_queue_get_cur_queues(void)
+{
+	return num_queues;
+}
+
+/*----------------------------------------------------------------*/
+
+/* assign queue id and insert to list */
+static int queue_list_add(struct snd_seq_queue *q)
+{
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue_list_lock, flags);
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		if (! queue_list[i]) {
+			queue_list[i] = q;
+			q->queue = i;
+			num_queues++;
+			spin_unlock_irqrestore(&queue_list_lock, flags);
+			return i;
+		}
+	}
+	spin_unlock_irqrestore(&queue_list_lock, flags);
+	return -1;
+}
+
+static struct snd_seq_queue *queue_list_remove(int id, int client)
+{
+	struct snd_seq_queue *q;
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue_list_lock, flags);
+	q = queue_list[id];
+	if (q) {
+		spin_lock(&q->owner_lock);
+		if (q->owner == client) {
+			/* found */
+			q->klocked = 1;
+			spin_unlock(&q->owner_lock);
+			queue_list[id] = NULL;
+			num_queues--;
+			spin_unlock_irqrestore(&queue_list_lock, flags);
+			return q;
+		}
+		spin_unlock(&q->owner_lock);
+	}
+	spin_unlock_irqrestore(&queue_list_lock, flags);
+	return NULL;
+}
+
+/*----------------------------------------------------------------*/
+
+/* create new queue (constructor) */
+static struct snd_seq_queue *queue_new(int owner, int locked)
+{
+	struct snd_seq_queue *q;
+
+	q = kzalloc(sizeof(*q), GFP_KERNEL);
+	if (!q)
+		return NULL;
+
+	spin_lock_init(&q->owner_lock);
+	spin_lock_init(&q->check_lock);
+	mutex_init(&q->timer_mutex);
+	snd_use_lock_init(&q->use_lock);
+	q->queue = -1;
+
+	q->tickq = snd_seq_prioq_new();
+	q->timeq = snd_seq_prioq_new();
+	q->timer = snd_seq_timer_new();
+	if (q->tickq == NULL || q->timeq == NULL || q->timer == NULL) {
+		snd_seq_prioq_delete(&q->tickq);
+		snd_seq_prioq_delete(&q->timeq);
+		snd_seq_timer_delete(&q->timer);
+		kfree(q);
+		return NULL;
+	}
+
+	q->owner = owner;
+	q->locked = locked;
+	q->klocked = 0;
+
+	return q;
+}
+
+/* delete queue (destructor) */
+static void queue_delete(struct snd_seq_queue *q)
+{
+	/* stop and release the timer */
+	mutex_lock(&q->timer_mutex);
+	snd_seq_timer_stop(q->timer);
+	snd_seq_timer_close(q);
+	mutex_unlock(&q->timer_mutex);
+	/* wait until access free */
+	snd_use_lock_sync(&q->use_lock);
+	/* release resources... */
+	snd_seq_prioq_delete(&q->tickq);
+	snd_seq_prioq_delete(&q->timeq);
+	snd_seq_timer_delete(&q->timer);
+
+	kfree(q);
+}
+
+
+/*----------------------------------------------------------------*/
+
+/* delete all existing queues */
+void snd_seq_queues_delete(void)
+{
+	int i;
+
+	/* clear list */
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		if (queue_list[i])
+			queue_delete(queue_list[i]);
+	}
+}
+
+static void queue_use(struct snd_seq_queue *queue, int client, int use);
+
+/* allocate a new queue -
+ * return pointer to new queue or ERR_PTR(-errno) for error
+ * The new queue's use_lock is set to 1. It is the caller's responsibility to
+ * call snd_use_lock_free(&q->use_lock).
+ */
+struct snd_seq_queue *snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
+{
+	struct snd_seq_queue *q;
+
+	q = queue_new(client, locked);
+	if (q == NULL)
+		return ERR_PTR(-ENOMEM);
+	q->info_flags = info_flags;
+	queue_use(q, client, 1);
+	snd_use_lock_use(&q->use_lock);
+	if (queue_list_add(q) < 0) {
+		snd_use_lock_free(&q->use_lock);
+		queue_delete(q);
+		return ERR_PTR(-ENOMEM);
+	}
+	return q;
+}
+
+/* delete a queue - queue must be owned by the client */
+int snd_seq_queue_delete(int client, int queueid)
+{
+	struct snd_seq_queue *q;
+
+	if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
+		return -EINVAL;
+	q = queue_list_remove(queueid, client);
+	if (q == NULL)
+		return -EINVAL;
+	queue_delete(q);
+
+	return 0;
+}
+
+
+/* return pointer to queue structure for specified id */
+struct snd_seq_queue *queueptr(int queueid)
+{
+	struct snd_seq_queue *q;
+	unsigned long flags;
+
+	if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
+		return NULL;
+	spin_lock_irqsave(&queue_list_lock, flags);
+	q = queue_list[queueid];
+	if (q)
+		snd_use_lock_use(&q->use_lock);
+	spin_unlock_irqrestore(&queue_list_lock, flags);
+	return q;
+}
+
+/* return the (first) queue matching with the specified name */
+struct snd_seq_queue *snd_seq_queue_find_name(char *name)
+{
+	int i;
+	struct snd_seq_queue *q;
+
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		q = queueptr(i);
+		if (q) {
+			if (strncmp(q->name, name, sizeof(q->name)) == 0)
+				return q;
+			queuefree(q);
+		}
+	}
+	return NULL;
+}
+
+
+/* -------------------------------------------------------- */
+
+#define MAX_CELL_PROCESSES_IN_QUEUE	1000
+
+void snd_seq_check_queue(struct snd_seq_queue *q, int atomic, int hop)
+{
+	unsigned long flags;
+	struct snd_seq_event_cell *cell;
+	snd_seq_tick_time_t cur_tick;
+	snd_seq_real_time_t cur_time;
+	int processed = 0;
+
+	if (q == NULL)
+		return;
+
+	/* make this function non-reentrant */
+	spin_lock_irqsave(&q->check_lock, flags);
+	if (q->check_blocked) {
+		q->check_again = 1;
+		spin_unlock_irqrestore(&q->check_lock, flags);
+		return;		/* other thread is already checking queues */
+	}
+	q->check_blocked = 1;
+	spin_unlock_irqrestore(&q->check_lock, flags);
+
+      __again:
+	/* Process tick queue... */
+	cur_tick = snd_seq_timer_get_cur_tick(q->timer);
+	for (;;) {
+		cell = snd_seq_prioq_cell_out(q->tickq, &cur_tick);
+		if (!cell)
+			break;
+		snd_seq_dispatch_event(cell, atomic, hop);
+		if (++processed >= MAX_CELL_PROCESSES_IN_QUEUE)
+			goto out; /* the rest processed at the next batch */
+	}
+
+	/* Process time queue... */
+	cur_time = snd_seq_timer_get_cur_time(q->timer, false);
+	for (;;) {
+		cell = snd_seq_prioq_cell_out(q->timeq, &cur_time);
+		if (!cell)
+			break;
+		snd_seq_dispatch_event(cell, atomic, hop);
+		if (++processed >= MAX_CELL_PROCESSES_IN_QUEUE)
+			goto out; /* the rest processed at the next batch */
+	}
+
+ out:
+	/* free lock */
+	spin_lock_irqsave(&q->check_lock, flags);
+	if (q->check_again) {
+		q->check_again = 0;
+		if (processed < MAX_CELL_PROCESSES_IN_QUEUE) {
+			spin_unlock_irqrestore(&q->check_lock, flags);
+			goto __again;
+		}
+	}
+	q->check_blocked = 0;
+	spin_unlock_irqrestore(&q->check_lock, flags);
+}
+
+
+/* enqueue a event to singe queue */
+int snd_seq_enqueue_event(struct snd_seq_event_cell *cell, int atomic, int hop)
+{
+	int dest, err;
+	struct snd_seq_queue *q;
+
+	if (snd_BUG_ON(!cell))
+		return -EINVAL;
+	dest = cell->event.queue;	/* destination queue */
+	q = queueptr(dest);
+	if (q == NULL)
+		return -EINVAL;
+	/* handle relative time stamps, convert them into absolute */
+	if ((cell->event.flags & SNDRV_SEQ_TIME_MODE_MASK) == SNDRV_SEQ_TIME_MODE_REL) {
+		switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
+		case SNDRV_SEQ_TIME_STAMP_TICK:
+			cell->event.time.tick += q->timer->tick.cur_tick;
+			break;
+
+		case SNDRV_SEQ_TIME_STAMP_REAL:
+			snd_seq_inc_real_time(&cell->event.time.time,
+					      &q->timer->cur_time);
+			break;
+		}
+		cell->event.flags &= ~SNDRV_SEQ_TIME_MODE_MASK;
+		cell->event.flags |= SNDRV_SEQ_TIME_MODE_ABS;
+	}
+	/* enqueue event in the real-time or midi queue */
+	switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
+	case SNDRV_SEQ_TIME_STAMP_TICK:
+		err = snd_seq_prioq_cell_in(q->tickq, cell);
+		break;
+
+	case SNDRV_SEQ_TIME_STAMP_REAL:
+	default:
+		err = snd_seq_prioq_cell_in(q->timeq, cell);
+		break;
+	}
+
+	if (err < 0) {
+		queuefree(q); /* unlock */
+		return err;
+	}
+
+	/* trigger dispatching */
+	snd_seq_check_queue(q, atomic, hop);
+
+	queuefree(q); /* unlock */
+
+	return 0;
+}
+
+
+/*----------------------------------------------------------------*/
+
+static inline int check_access(struct snd_seq_queue *q, int client)
+{
+	return (q->owner == client) || (!q->locked && !q->klocked);
+}
+
+/* check if the client has permission to modify queue parameters.
+ * if it does, lock the queue
+ */
+static int queue_access_lock(struct snd_seq_queue *q, int client)
+{
+	unsigned long flags;
+	int access_ok;
+	
+	spin_lock_irqsave(&q->owner_lock, flags);
+	access_ok = check_access(q, client);
+	if (access_ok)
+		q->klocked = 1;
+	spin_unlock_irqrestore(&q->owner_lock, flags);
+	return access_ok;
+}
+
+/* unlock the queue */
+static inline void queue_access_unlock(struct snd_seq_queue *q)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->owner_lock, flags);
+	q->klocked = 0;
+	spin_unlock_irqrestore(&q->owner_lock, flags);
+}
+
+/* exported - only checking permission */
+int snd_seq_queue_check_access(int queueid, int client)
+{
+	struct snd_seq_queue *q = queueptr(queueid);
+	int access_ok;
+	unsigned long flags;
+
+	if (! q)
+		return 0;
+	spin_lock_irqsave(&q->owner_lock, flags);
+	access_ok = check_access(q, client);
+	spin_unlock_irqrestore(&q->owner_lock, flags);
+	queuefree(q);
+	return access_ok;
+}
+
+/*----------------------------------------------------------------*/
+
+/*
+ * change queue's owner and permission
+ */
+int snd_seq_queue_set_owner(int queueid, int client, int locked)
+{
+	struct snd_seq_queue *q = queueptr(queueid);
+	unsigned long flags;
+
+	if (q == NULL)
+		return -EINVAL;
+
+	if (! queue_access_lock(q, client)) {
+		queuefree(q);
+		return -EPERM;
+	}
+
+	spin_lock_irqsave(&q->owner_lock, flags);
+	q->locked = locked ? 1 : 0;
+	q->owner = client;
+	spin_unlock_irqrestore(&q->owner_lock, flags);
+	queue_access_unlock(q);
+	queuefree(q);
+
+	return 0;
+}
+
+
+/*----------------------------------------------------------------*/
+
+/* open timer -
+ * q->use mutex should be down before calling this function to avoid
+ * confliction with snd_seq_queue_use()
+ */
+int snd_seq_queue_timer_open(int queueid)
+{
+	int result = 0;
+	struct snd_seq_queue *queue;
+	struct snd_seq_timer *tmr;
+
+	queue = queueptr(queueid);
+	if (queue == NULL)
+		return -EINVAL;
+	tmr = queue->timer;
+	result = snd_seq_timer_open(queue);
+	if (result < 0) {
+		snd_seq_timer_defaults(tmr);
+		result = snd_seq_timer_open(queue);
+	}
+	queuefree(queue);
+	return result;
+}
+
+/* close timer -
+ * q->use mutex should be down before calling this function
+ */
+int snd_seq_queue_timer_close(int queueid)
+{
+	struct snd_seq_queue *queue;
+	int result = 0;
+
+	queue = queueptr(queueid);
+	if (queue == NULL)
+		return -EINVAL;
+	snd_seq_timer_close(queue);
+	queuefree(queue);
+	return result;
+}
+
+/* change queue tempo and ppq */
+int snd_seq_queue_timer_set_tempo(int queueid, int client,
+				  struct snd_seq_queue_tempo *info)
+{
+	struct snd_seq_queue *q = queueptr(queueid);
+	int result;
+
+	if (q == NULL)
+		return -EINVAL;
+	if (! queue_access_lock(q, client)) {
+		queuefree(q);
+		return -EPERM;
+	}
+
+	result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq);
+	if (result >= 0 && info->skew_base > 0)
+		result = snd_seq_timer_set_skew(q->timer, info->skew_value,
+						info->skew_base);
+	queue_access_unlock(q);
+	queuefree(q);
+	return result;
+}
+
+/* use or unuse this queue */
+static void queue_use(struct snd_seq_queue *queue, int client, int use)
+{
+	if (use) {
+		if (!test_and_set_bit(client, queue->clients_bitmap))
+			queue->clients++;
+	} else {
+		if (test_and_clear_bit(client, queue->clients_bitmap))
+			queue->clients--;
+	}
+	if (queue->clients) {
+		if (use && queue->clients == 1)
+			snd_seq_timer_defaults(queue->timer);
+		snd_seq_timer_open(queue);
+	} else {
+		snd_seq_timer_close(queue);
+	}
+}
+
+/* use or unuse this queue -
+ * if it is the first client, starts the timer.
+ * if it is not longer used by any clients, stop the timer.
+ */
+int snd_seq_queue_use(int queueid, int client, int use)
+{
+	struct snd_seq_queue *queue;
+
+	queue = queueptr(queueid);
+	if (queue == NULL)
+		return -EINVAL;
+	mutex_lock(&queue->timer_mutex);
+	queue_use(queue, client, use);
+	mutex_unlock(&queue->timer_mutex);
+	queuefree(queue);
+	return 0;
+}
+
+/*
+ * check if queue is used by the client
+ * return negative value if the queue is invalid.
+ * return 0 if not used, 1 if used.
+ */
+int snd_seq_queue_is_used(int queueid, int client)
+{
+	struct snd_seq_queue *q;
+	int result;
+
+	q = queueptr(queueid);
+	if (q == NULL)
+		return -EINVAL; /* invalid queue */
+	result = test_bit(client, q->clients_bitmap) ? 1 : 0;
+	queuefree(q);
+	return result;
+}
+
+
+/*----------------------------------------------------------------*/
+
+/* final stage notification -
+ * remove cells for no longer exist client (for non-owned queue)
+ * or delete this queue (for owned queue)
+ */
+void snd_seq_queue_client_leave(int client)
+{
+	int i;
+	struct snd_seq_queue *q;
+
+	/* delete own queues from queue list */
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		q = queue_list_remove(i, client);
+		if (q)
+			queue_delete(q);
+	}
+
+	/* remove cells from existing queues -
+	 * they are not owned by this client
+	 */
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		q = queueptr(i);
+		if (!q)
+			continue;
+		if (test_bit(client, q->clients_bitmap)) {
+			snd_seq_prioq_leave(q->tickq, client, 0);
+			snd_seq_prioq_leave(q->timeq, client, 0);
+			snd_seq_queue_use(q->queue, client, 0);
+		}
+		queuefree(q);
+	}
+}
+
+
+
+/*----------------------------------------------------------------*/
+
+/* remove cells from all queues */
+void snd_seq_queue_client_leave_cells(int client)
+{
+	int i;
+	struct snd_seq_queue *q;
+
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		q = queueptr(i);
+		if (!q)
+			continue;
+		snd_seq_prioq_leave(q->tickq, client, 0);
+		snd_seq_prioq_leave(q->timeq, client, 0);
+		queuefree(q);
+	}
+}
+
+/* remove cells based on flush criteria */
+void snd_seq_queue_remove_cells(int client, struct snd_seq_remove_events *info)
+{
+	int i;
+	struct snd_seq_queue *q;
+
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		q = queueptr(i);
+		if (!q)
+			continue;
+		if (test_bit(client, q->clients_bitmap) &&
+		    (! (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) ||
+		     q->queue == info->queue)) {
+			snd_seq_prioq_remove_events(q->tickq, client, info);
+			snd_seq_prioq_remove_events(q->timeq, client, info);
+		}
+		queuefree(q);
+	}
+}
+
+/*----------------------------------------------------------------*/
+
+/*
+ * send events to all subscribed ports
+ */
+static void queue_broadcast_event(struct snd_seq_queue *q, struct snd_seq_event *ev,
+				  int atomic, int hop)
+{
+	struct snd_seq_event sev;
+
+	sev = *ev;
+	
+	sev.flags = SNDRV_SEQ_TIME_STAMP_TICK|SNDRV_SEQ_TIME_MODE_ABS;
+	sev.time.tick = q->timer->tick.cur_tick;
+	sev.queue = q->queue;
+	sev.data.queue.queue = q->queue;
+
+	/* broadcast events from Timer port */
+	sev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
+	sev.source.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
+	sev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+	snd_seq_kernel_client_dispatch(SNDRV_SEQ_CLIENT_SYSTEM, &sev, atomic, hop);
+}
+
+/*
+ * process a received queue-control event.
+ * this function is exported for seq_sync.c.
+ */
+static void snd_seq_queue_process_event(struct snd_seq_queue *q,
+					struct snd_seq_event *ev,
+					int atomic, int hop)
+{
+	switch (ev->type) {
+	case SNDRV_SEQ_EVENT_START:
+		snd_seq_prioq_leave(q->tickq, ev->source.client, 1);
+		snd_seq_prioq_leave(q->timeq, ev->source.client, 1);
+		if (! snd_seq_timer_start(q->timer))
+			queue_broadcast_event(q, ev, atomic, hop);
+		break;
+
+	case SNDRV_SEQ_EVENT_CONTINUE:
+		if (! snd_seq_timer_continue(q->timer))
+			queue_broadcast_event(q, ev, atomic, hop);
+		break;
+
+	case SNDRV_SEQ_EVENT_STOP:
+		snd_seq_timer_stop(q->timer);
+		queue_broadcast_event(q, ev, atomic, hop);
+		break;
+
+	case SNDRV_SEQ_EVENT_TEMPO:
+		snd_seq_timer_set_tempo(q->timer, ev->data.queue.param.value);
+		queue_broadcast_event(q, ev, atomic, hop);
+		break;
+
+	case SNDRV_SEQ_EVENT_SETPOS_TICK:
+		if (snd_seq_timer_set_position_tick(q->timer, ev->data.queue.param.time.tick) == 0) {
+			queue_broadcast_event(q, ev, atomic, hop);
+		}
+		break;
+
+	case SNDRV_SEQ_EVENT_SETPOS_TIME:
+		if (snd_seq_timer_set_position_time(q->timer, ev->data.queue.param.time.time) == 0) {
+			queue_broadcast_event(q, ev, atomic, hop);
+		}
+		break;
+	case SNDRV_SEQ_EVENT_QUEUE_SKEW:
+		if (snd_seq_timer_set_skew(q->timer,
+					   ev->data.queue.param.skew.value,
+					   ev->data.queue.param.skew.base) == 0) {
+			queue_broadcast_event(q, ev, atomic, hop);
+		}
+		break;
+	}
+}
+
+
+/*
+ * Queue control via timer control port:
+ * this function is exported as a callback of timer port.
+ */
+int snd_seq_control_queue(struct snd_seq_event *ev, int atomic, int hop)
+{
+	struct snd_seq_queue *q;
+
+	if (snd_BUG_ON(!ev))
+		return -EINVAL;
+	q = queueptr(ev->data.queue.queue);
+
+	if (q == NULL)
+		return -EINVAL;
+
+	if (! queue_access_lock(q, ev->source.client)) {
+		queuefree(q);
+		return -EPERM;
+	}
+
+	snd_seq_queue_process_event(q, ev, atomic, hop);
+
+	queue_access_unlock(q);
+	queuefree(q);
+	return 0;
+}
+
+
+/*----------------------------------------------------------------*/
+
+#ifdef CONFIG_SND_PROC_FS
+/* exported to seq_info.c */
+void snd_seq_info_queues_read(struct snd_info_entry *entry, 
+			      struct snd_info_buffer *buffer)
+{
+	int i, bpm;
+	struct snd_seq_queue *q;
+	struct snd_seq_timer *tmr;
+	bool locked;
+	int owner;
+
+	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
+		q = queueptr(i);
+		if (!q)
+			continue;
+
+		tmr = q->timer;
+		if (tmr->tempo)
+			bpm = 60000000 / tmr->tempo;
+		else
+			bpm = 0;
+
+		spin_lock_irq(&q->owner_lock);
+		locked = q->locked;
+		owner = q->owner;
+		spin_unlock_irq(&q->owner_lock);
+
+		snd_iprintf(buffer, "queue %d: [%s]\n", q->queue, q->name);
+		snd_iprintf(buffer, "owned by client    : %d\n", owner);
+		snd_iprintf(buffer, "lock status        : %s\n", locked ? "Locked" : "Free");
+		snd_iprintf(buffer, "queued time events : %d\n", snd_seq_prioq_avail(q->timeq));
+		snd_iprintf(buffer, "queued tick events : %d\n", snd_seq_prioq_avail(q->tickq));
+		snd_iprintf(buffer, "timer state        : %s\n", tmr->running ? "Running" : "Stopped");
+		snd_iprintf(buffer, "timer PPQ          : %d\n", tmr->ppq);
+		snd_iprintf(buffer, "current tempo      : %d\n", tmr->tempo);
+		snd_iprintf(buffer, "current BPM        : %d\n", bpm);
+		snd_iprintf(buffer, "current time       : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
+		snd_iprintf(buffer, "current tick       : %d\n", tmr->tick.cur_tick);
+		snd_iprintf(buffer, "\n");
+		queuefree(q);
+	}
+}
+#endif /* CONFIG_SND_PROC_FS */
+
diff --git a/sound/core/seq/seq_queue.h b/sound/core/seq/seq_queue.h
new file mode 100644
index 0000000000..c69105dc1a
--- /dev/null
+++ b/sound/core/seq/seq_queue.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer Queue handling
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_QUEUE_H
+#define __SND_SEQ_QUEUE_H
+
+#include "seq_memory.h"
+#include "seq_prioq.h"
+#include "seq_timer.h"
+#include "seq_lock.h"
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/bitops.h>
+
+#define SEQ_QUEUE_NO_OWNER (-1)
+
+struct snd_seq_queue {
+	int queue;		/* queue number */
+
+	char name[64];		/* name of this queue */
+
+	struct snd_seq_prioq	*tickq;		/* midi tick event queue */
+	struct snd_seq_prioq	*timeq;		/* real-time event queue */	
+	
+	struct snd_seq_timer *timer;	/* time keeper for this queue */
+	int	owner;		/* client that 'owns' the timer */
+	bool	locked;		/* timer is only accesibble by owner if set */
+	bool	klocked;	/* kernel lock (after START) */
+	bool	check_again;	/* concurrent access happened during check */
+	bool	check_blocked;	/* queue being checked */
+
+	unsigned int flags;		/* status flags */
+	unsigned int info_flags;	/* info for sync */
+
+	spinlock_t owner_lock;
+	spinlock_t check_lock;
+
+	/* clients which uses this queue (bitmap) */
+	DECLARE_BITMAP(clients_bitmap, SNDRV_SEQ_MAX_CLIENTS);
+	unsigned int clients;	/* users of this queue */
+	struct mutex timer_mutex;
+
+	snd_use_lock_t use_lock;
+};
+
+
+/* get the number of current queues */
+int snd_seq_queue_get_cur_queues(void);
+
+/* delete queues */ 
+void snd_seq_queues_delete(void);
+
+
+/* create new queue (constructor) */
+struct snd_seq_queue *snd_seq_queue_alloc(int client, int locked, unsigned int flags);
+
+/* delete queue (destructor) */
+int snd_seq_queue_delete(int client, int queueid);
+
+/* final stage */
+void snd_seq_queue_client_leave(int client);
+
+/* enqueue a event received from one the clients */
+int snd_seq_enqueue_event(struct snd_seq_event_cell *cell, int atomic, int hop);
+
+/* Remove events */
+void snd_seq_queue_client_leave_cells(int client);
+void snd_seq_queue_remove_cells(int client, struct snd_seq_remove_events *info);
+
+/* return pointer to queue structure for specified id */
+struct snd_seq_queue *queueptr(int queueid);
+/* unlock */
+#define queuefree(q) snd_use_lock_free(&(q)->use_lock)
+
+/* return the (first) queue matching with the specified name */
+struct snd_seq_queue *snd_seq_queue_find_name(char *name);
+
+/* check single queue and dispatch events */
+void snd_seq_check_queue(struct snd_seq_queue *q, int atomic, int hop);
+
+/* access to queue's parameters */
+int snd_seq_queue_check_access(int queueid, int client);
+int snd_seq_queue_timer_set_tempo(int queueid, int client, struct snd_seq_queue_tempo *info);
+int snd_seq_queue_set_owner(int queueid, int client, int locked);
+int snd_seq_queue_set_locked(int queueid, int client, int locked);
+int snd_seq_queue_timer_open(int queueid);
+int snd_seq_queue_timer_close(int queueid);
+int snd_seq_queue_use(int queueid, int client, int use);
+int snd_seq_queue_is_used(int queueid, int client);
+
+int snd_seq_control_queue(struct snd_seq_event *ev, int atomic, int hop);
+
+#endif
diff --git a/sound/core/seq/seq_system.c b/sound/core/seq/seq_system.c
new file mode 100644
index 0000000000..8026729019
--- /dev/null
+++ b/sound/core/seq/seq_system.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer System services Client
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include "seq_system.h"
+#include "seq_timer.h"
+#include "seq_queue.h"
+
+/* internal client that provide system services, access to timer etc. */
+
+/*
+ * Port "Timer"
+ *      - send tempo /start/stop etc. events to this port to manipulate the 
+ *        queue's timer. The queue address is specified in
+ *	  data.queue.queue.
+ *      - this port supports subscription. The received timer events are 
+ *        broadcasted to all subscribed clients. The modified tempo
+ *	  value is stored on data.queue.value.
+ *	  The modifier client/port is not send.
+ *
+ * Port "Announce"
+ *      - does not receive message
+ *      - supports supscription. For each client or port attaching to or 
+ *        detaching from the system an announcement is send to the subscribed
+ *        clients.
+ *
+ * Idea: the subscription mechanism might also work handy for distributing 
+ * synchronisation and timing information. In this case we would ideally have
+ * a list of subscribers for each type of sync (time, tick), for each timing
+ * queue.
+ *
+ * NOTE: the queue to be started, stopped, etc. must be specified
+ *	 in data.queue.addr.queue field.  queue is used only for
+ *	 scheduling, and no longer referred as affected queue.
+ *	 They are used only for timer broadcast (see above).
+ *							-- iwai
+ */
+
+
+/* client id of our system client */
+static int sysclient = -1;
+
+/* port id numbers for this client */
+static int announce_port = -1;
+
+
+
+/* fill standard header data, source port & channel are filled in */
+static int setheader(struct snd_seq_event * ev, int client, int port)
+{
+	if (announce_port < 0)
+		return -ENODEV;
+
+	memset(ev, 0, sizeof(struct snd_seq_event));
+
+	ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+	ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
+
+	ev->source.client = sysclient;
+	ev->source.port = announce_port;
+	ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+
+	/* fill data */
+	/*ev->data.addr.queue = SNDRV_SEQ_ADDRESS_UNKNOWN;*/
+	ev->data.addr.client = client;
+	ev->data.addr.port = port;
+
+	return 0;
+}
+
+
+/* entry points for broadcasting system events */
+void snd_seq_system_broadcast(int client, int port, int type)
+{
+	struct snd_seq_event ev;
+	
+	if (setheader(&ev, client, port) < 0)
+		return;
+	ev.type = type;
+	snd_seq_kernel_client_dispatch(sysclient, &ev, 0, 0);
+}
+EXPORT_SYMBOL_GPL(snd_seq_system_broadcast);
+
+/* entry points for broadcasting system events */
+int snd_seq_system_notify(int client, int port, struct snd_seq_event *ev)
+{
+	ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+	ev->source.client = sysclient;
+	ev->source.port = announce_port;
+	ev->dest.client = client;
+	ev->dest.port = port;
+	return snd_seq_kernel_client_dispatch(sysclient, ev, 0, 0);
+}
+
+/* call-back handler for timer events */
+static int event_input_timer(struct snd_seq_event * ev, int direct, void *private_data, int atomic, int hop)
+{
+	return snd_seq_control_queue(ev, atomic, hop);
+}
+
+/* register our internal client */
+int __init snd_seq_system_client_init(void)
+{
+	struct snd_seq_port_callback pcallbacks;
+	struct snd_seq_port_info *port;
+	int err;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	memset(&pcallbacks, 0, sizeof(pcallbacks));
+	pcallbacks.owner = THIS_MODULE;
+	pcallbacks.event_input = event_input_timer;
+
+	/* register client */
+	sysclient = snd_seq_create_kernel_client(NULL, 0, "System");
+	if (sysclient < 0) {
+		kfree(port);
+		return sysclient;
+	}
+
+	/* register timer */
+	strcpy(port->name, "Timer");
+	port->capability = SNDRV_SEQ_PORT_CAP_WRITE; /* accept queue control */
+	port->capability |= SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast */
+	port->kernel = &pcallbacks;
+	port->type = 0;
+	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+	port->addr.client = sysclient;
+	port->addr.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
+	err = snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT,
+					port);
+	if (err < 0)
+		goto error_port;
+
+	/* register announcement port */
+	strcpy(port->name, "Announce");
+	port->capability = SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast only */
+	port->kernel = NULL;
+	port->type = 0;
+	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+	port->addr.client = sysclient;
+	port->addr.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
+	err = snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT,
+					port);
+	if (err < 0)
+		goto error_port;
+	announce_port = port->addr.port;
+
+	kfree(port);
+	return 0;
+
+ error_port:
+	snd_seq_system_client_done();
+	kfree(port);
+	return err;
+}
+
+
+/* unregister our internal client */
+void snd_seq_system_client_done(void)
+{
+	int oldsysclient = sysclient;
+
+	if (oldsysclient >= 0) {
+		sysclient = -1;
+		announce_port = -1;
+		snd_seq_delete_kernel_client(oldsysclient);
+	}
+}
diff --git a/sound/core/seq/seq_system.h b/sound/core/seq/seq_system.h
new file mode 100644
index 0000000000..4fe88ad403
--- /dev/null
+++ b/sound/core/seq/seq_system.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  ALSA sequencer System Client
+ *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_SYSTEM_H
+#define __SND_SEQ_SYSTEM_H
+
+#include <sound/seq_kernel.h>
+
+
+/* entry points for broadcasting system events */
+void snd_seq_system_broadcast(int client, int port, int type);
+
+#define snd_seq_system_client_ev_client_start(client) snd_seq_system_broadcast(client, 0, SNDRV_SEQ_EVENT_CLIENT_START)
+#define snd_seq_system_client_ev_client_exit(client) snd_seq_system_broadcast(client, 0, SNDRV_SEQ_EVENT_CLIENT_EXIT)
+#define snd_seq_system_client_ev_client_change(client) snd_seq_system_broadcast(client, 0, SNDRV_SEQ_EVENT_CLIENT_CHANGE)
+#define snd_seq_system_client_ev_port_start(client, port) snd_seq_system_broadcast(client, port, SNDRV_SEQ_EVENT_PORT_START)
+#define snd_seq_system_client_ev_port_exit(client, port) snd_seq_system_broadcast(client, port, SNDRV_SEQ_EVENT_PORT_EXIT)
+#define snd_seq_system_client_ev_port_change(client, port) snd_seq_system_broadcast(client, port, SNDRV_SEQ_EVENT_PORT_CHANGE)
+
+int snd_seq_system_notify(int client, int port, struct snd_seq_event *ev);
+
+/* register our internal client */
+int snd_seq_system_client_init(void);
+
+/* unregister our internal client */
+void snd_seq_system_client_done(void);
+
+
+#endif
diff --git a/sound/core/seq/seq_timer.c b/sound/core/seq/seq_timer.c
new file mode 100644
index 0000000000..9863be6fd4
--- /dev/null
+++ b/sound/core/seq/seq_timer.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer Timer
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *                              Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <sound/core.h>
+#include <linux/slab.h>
+#include "seq_timer.h"
+#include "seq_queue.h"
+#include "seq_info.h"
+
+/* allowed sequencer timer frequencies, in Hz */
+#define MIN_FREQUENCY		10
+#define MAX_FREQUENCY		6250
+#define DEFAULT_FREQUENCY	1000
+
+#define SKEW_BASE	0x10000	/* 16bit shift */
+
+static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr)
+{
+	if (tmr->tempo < 1000000)
+		tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq;
+	else {
+		/* might overflow.. */
+		unsigned int s;
+		s = tmr->tempo % tmr->ppq;
+		s = (s * 1000) / tmr->ppq;
+		tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
+		tmr->tick.resolution += s;
+	}
+	if (tmr->tick.resolution <= 0)
+		tmr->tick.resolution = 1;
+	snd_seq_timer_update_tick(&tmr->tick, 0);
+}
+
+/* create new timer (constructor) */
+struct snd_seq_timer *snd_seq_timer_new(void)
+{
+	struct snd_seq_timer *tmr;
+	
+	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
+	if (!tmr)
+		return NULL;
+	spin_lock_init(&tmr->lock);
+
+	/* reset setup to defaults */
+	snd_seq_timer_defaults(tmr);
+	
+	/* reset time */
+	snd_seq_timer_reset(tmr);
+	
+	return tmr;
+}
+
+/* delete timer (destructor) */
+void snd_seq_timer_delete(struct snd_seq_timer **tmr)
+{
+	struct snd_seq_timer *t = *tmr;
+	*tmr = NULL;
+
+	if (t == NULL) {
+		pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n");
+		return;
+	}
+	t->running = 0;
+
+	/* reset time */
+	snd_seq_timer_stop(t);
+	snd_seq_timer_reset(t);
+
+	kfree(t);
+}
+
+void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	/* setup defaults */
+	tmr->ppq = 96;		/* 96 PPQ */
+	tmr->tempo = 500000;	/* 120 BPM */
+	snd_seq_timer_set_tick_resolution(tmr);
+	tmr->running = 0;
+
+	tmr->type = SNDRV_SEQ_TIMER_ALSA;
+	tmr->alsa_id.dev_class = seq_default_timer_class;
+	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
+	tmr->alsa_id.card = seq_default_timer_card;
+	tmr->alsa_id.device = seq_default_timer_device;
+	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
+	tmr->preferred_resolution = seq_default_timer_resolution;
+
+	tmr->skew = tmr->skew_base = SKEW_BASE;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+}
+
+static void seq_timer_reset(struct snd_seq_timer *tmr)
+{
+	/* reset time & songposition */
+	tmr->cur_time.tv_sec = 0;
+	tmr->cur_time.tv_nsec = 0;
+
+	tmr->tick.cur_tick = 0;
+	tmr->tick.fraction = 0;
+}
+
+void snd_seq_timer_reset(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	seq_timer_reset(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+}
+
+
+/* called by timer interrupt routine. the period time since previous invocation is passed */
+static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
+				    unsigned long resolution,
+				    unsigned long ticks)
+{
+	unsigned long flags;
+	struct snd_seq_queue *q = timeri->callback_data;
+	struct snd_seq_timer *tmr;
+
+	if (q == NULL)
+		return;
+	tmr = q->timer;
+	if (tmr == NULL)
+		return;
+	spin_lock_irqsave(&tmr->lock, flags);
+	if (!tmr->running) {
+		spin_unlock_irqrestore(&tmr->lock, flags);
+		return;
+	}
+
+	resolution *= ticks;
+	if (tmr->skew != tmr->skew_base) {
+		/* FIXME: assuming skew_base = 0x10000 */
+		resolution = (resolution >> 16) * tmr->skew +
+			(((resolution & 0xffff) * tmr->skew) >> 16);
+	}
+
+	/* update timer */
+	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
+
+	/* calculate current tick */
+	snd_seq_timer_update_tick(&tmr->tick, resolution);
+
+	/* register actual time of this timer update */
+	ktime_get_ts64(&tmr->last_update);
+
+	spin_unlock_irqrestore(&tmr->lock, flags);
+
+	/* check queues and dispatch events */
+	snd_seq_check_queue(q, 1, 0);
+}
+
+/* set current tempo */
+int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	if (tempo <= 0)
+		return -EINVAL;
+	spin_lock_irqsave(&tmr->lock, flags);
+	if ((unsigned int)tempo != tmr->tempo) {
+		tmr->tempo = tempo;
+		snd_seq_timer_set_tick_resolution(tmr);
+	}
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set current tempo and ppq in a shot */
+int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
+{
+	int changed;
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	if (tempo <= 0 || ppq <= 0)
+		return -EINVAL;
+	spin_lock_irqsave(&tmr->lock, flags);
+	if (tmr->running && (ppq != tmr->ppq)) {
+		/* refuse to change ppq on running timers */
+		/* because it will upset the song position (ticks) */
+		spin_unlock_irqrestore(&tmr->lock, flags);
+		pr_debug("ALSA: seq: cannot change ppq of a running timer\n");
+		return -EBUSY;
+	}
+	changed = (tempo != tmr->tempo) || (ppq != tmr->ppq);
+	tmr->tempo = tempo;
+	tmr->ppq = ppq;
+	if (changed)
+		snd_seq_timer_set_tick_resolution(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set current tick position */
+int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
+				    snd_seq_tick_time_t position)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	tmr->tick.cur_tick = position;
+	tmr->tick.fraction = 0;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set current real-time position */
+int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
+				    snd_seq_real_time_t position)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+
+	snd_seq_sanity_real_time(&position);
+	spin_lock_irqsave(&tmr->lock, flags);
+	tmr->cur_time = position;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+/* set timer skew */
+int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
+			   unsigned int base)
+{
+	unsigned long flags;
+
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+
+	/* FIXME */
+	if (base != SKEW_BASE) {
+		pr_debug("ALSA: seq: invalid skew base 0x%x\n", base);
+		return -EINVAL;
+	}
+	spin_lock_irqsave(&tmr->lock, flags);
+	tmr->skew = skew;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return 0;
+}
+
+int snd_seq_timer_open(struct snd_seq_queue *q)
+{
+	struct snd_timer_instance *t;
+	struct snd_seq_timer *tmr;
+	char str[32];
+	int err;
+
+	tmr = q->timer;
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	if (tmr->timeri)
+		return -EBUSY;
+	sprintf(str, "sequencer queue %i", q->queue);
+	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
+		return -EINVAL;
+	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
+		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
+	t = snd_timer_instance_new(str);
+	if (!t)
+		return -ENOMEM;
+	t->callback = snd_seq_timer_interrupt;
+	t->callback_data = q;
+	t->flags |= SNDRV_TIMER_IFLG_AUTO;
+	err = snd_timer_open(t, &tmr->alsa_id, q->queue);
+	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
+		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
+		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
+			struct snd_timer_id tid;
+			memset(&tid, 0, sizeof(tid));
+			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
+			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
+			tid.card = -1;
+			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
+			err = snd_timer_open(t, &tid, q->queue);
+		}
+	}
+	if (err < 0) {
+		pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err);
+		snd_timer_instance_free(t);
+		return err;
+	}
+	spin_lock_irq(&tmr->lock);
+	if (tmr->timeri)
+		err = -EBUSY;
+	else
+		tmr->timeri = t;
+	spin_unlock_irq(&tmr->lock);
+	if (err < 0) {
+		snd_timer_close(t);
+		snd_timer_instance_free(t);
+		return err;
+	}
+	return 0;
+}
+
+int snd_seq_timer_close(struct snd_seq_queue *q)
+{
+	struct snd_seq_timer *tmr;
+	struct snd_timer_instance *t;
+	
+	tmr = q->timer;
+	if (snd_BUG_ON(!tmr))
+		return -EINVAL;
+	spin_lock_irq(&tmr->lock);
+	t = tmr->timeri;
+	tmr->timeri = NULL;
+	spin_unlock_irq(&tmr->lock);
+	if (t) {
+		snd_timer_close(t);
+		snd_timer_instance_free(t);
+	}
+	return 0;
+}
+
+static int seq_timer_stop(struct snd_seq_timer *tmr)
+{
+	if (! tmr->timeri)
+		return -EINVAL;
+	if (!tmr->running)
+		return 0;
+	tmr->running = 0;
+	snd_timer_pause(tmr->timeri);
+	return 0;
+}
+
+int snd_seq_timer_stop(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	err = seq_timer_stop(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return err;
+}
+
+static int initialize_timer(struct snd_seq_timer *tmr)
+{
+	struct snd_timer *t;
+	unsigned long freq;
+
+	t = tmr->timeri->timer;
+	if (!t)
+		return -EINVAL;
+
+	freq = tmr->preferred_resolution;
+	if (!freq)
+		freq = DEFAULT_FREQUENCY;
+	else if (freq < MIN_FREQUENCY)
+		freq = MIN_FREQUENCY;
+	else if (freq > MAX_FREQUENCY)
+		freq = MAX_FREQUENCY;
+
+	tmr->ticks = 1;
+	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
+		unsigned long r = snd_timer_resolution(tmr->timeri);
+		if (r) {
+			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
+			if (! tmr->ticks)
+				tmr->ticks = 1;
+		}
+	}
+	tmr->initialized = 1;
+	return 0;
+}
+
+static int seq_timer_start(struct snd_seq_timer *tmr)
+{
+	if (! tmr->timeri)
+		return -EINVAL;
+	if (tmr->running)
+		seq_timer_stop(tmr);
+	seq_timer_reset(tmr);
+	if (initialize_timer(tmr) < 0)
+		return -EINVAL;
+	snd_timer_start(tmr->timeri, tmr->ticks);
+	tmr->running = 1;
+	ktime_get_ts64(&tmr->last_update);
+	return 0;
+}
+
+int snd_seq_timer_start(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	err = seq_timer_start(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return err;
+}
+
+static int seq_timer_continue(struct snd_seq_timer *tmr)
+{
+	if (! tmr->timeri)
+		return -EINVAL;
+	if (tmr->running)
+		return -EBUSY;
+	if (! tmr->initialized) {
+		seq_timer_reset(tmr);
+		if (initialize_timer(tmr) < 0)
+			return -EINVAL;
+	}
+	snd_timer_start(tmr->timeri, tmr->ticks);
+	tmr->running = 1;
+	ktime_get_ts64(&tmr->last_update);
+	return 0;
+}
+
+int snd_seq_timer_continue(struct snd_seq_timer *tmr)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	err = seq_timer_continue(tmr);
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return err;
+}
+
+/* return current 'real' time. use timeofday() to get better granularity. */
+snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
+					       bool adjust_ktime)
+{
+	snd_seq_real_time_t cur_time;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	cur_time = tmr->cur_time;
+	if (adjust_ktime && tmr->running) {
+		struct timespec64 tm;
+
+		ktime_get_ts64(&tm);
+		tm = timespec64_sub(tm, tmr->last_update);
+		cur_time.tv_nsec += tm.tv_nsec;
+		cur_time.tv_sec += tm.tv_sec;
+		snd_seq_sanity_real_time(&cur_time);
+	}
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return cur_time;	
+}
+
+/* TODO: use interpolation on tick queue (will only be useful for very
+ high PPQ values) */
+snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
+{
+	snd_seq_tick_time_t cur_tick;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tmr->lock, flags);
+	cur_tick = tmr->tick.cur_tick;
+	spin_unlock_irqrestore(&tmr->lock, flags);
+	return cur_tick;
+}
+
+
+#ifdef CONFIG_SND_PROC_FS
+/* exported to seq_info.c */
+void snd_seq_info_timer_read(struct snd_info_entry *entry,
+			     struct snd_info_buffer *buffer)
+{
+	int idx;
+	struct snd_seq_queue *q;
+	struct snd_seq_timer *tmr;
+	struct snd_timer_instance *ti;
+	unsigned long resolution;
+	
+	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
+		q = queueptr(idx);
+		if (q == NULL)
+			continue;
+		mutex_lock(&q->timer_mutex);
+		tmr = q->timer;
+		if (!tmr)
+			goto unlock;
+		ti = tmr->timeri;
+		if (!ti)
+			goto unlock;
+		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
+		resolution = snd_timer_resolution(ti) * tmr->ticks;
+		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
+		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
+unlock:
+		mutex_unlock(&q->timer_mutex);
+		queuefree(q);
+ 	}
+}
+#endif /* CONFIG_SND_PROC_FS */
+
diff --git a/sound/core/seq/seq_timer.h b/sound/core/seq/seq_timer.h
new file mode 100644
index 0000000000..4bec57df81
--- /dev/null
+++ b/sound/core/seq/seq_timer.h
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  ALSA sequencer Timer
+ *  Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_TIMER_H
+#define __SND_SEQ_TIMER_H
+
+#include <sound/timer.h>
+#include <sound/seq_kernel.h>
+
+struct snd_seq_timer_tick {
+	snd_seq_tick_time_t	cur_tick;	/* current tick */
+	unsigned long		resolution;	/* time per tick in nsec */
+	unsigned long		fraction;	/* current time per tick in nsec */
+};
+
+struct snd_seq_timer {
+	/* ... tempo / offset / running state */
+
+	unsigned int		running:1,	/* running state of queue */	
+				initialized:1;	/* timer is initialized */
+
+	unsigned int		tempo;		/* current tempo, us/tick */
+	int			ppq;		/* time resolution, ticks/quarter */
+
+	snd_seq_real_time_t	cur_time;	/* current time */
+	struct snd_seq_timer_tick	tick;	/* current tick */
+	int tick_updated;
+	
+	int			type;		/* timer type */
+	struct snd_timer_id	alsa_id;	/* ALSA's timer ID */
+	struct snd_timer_instance	*timeri;	/* timer instance */
+	unsigned int		ticks;
+	unsigned long		preferred_resolution; /* timer resolution, ticks/sec */
+
+	unsigned int skew;
+	unsigned int skew_base;
+
+	struct timespec64	last_update;	 /* time of last clock update, used for interpolation */
+
+	spinlock_t lock;
+};
+
+
+/* create new timer (constructor) */
+struct snd_seq_timer *snd_seq_timer_new(void);
+
+/* delete timer (destructor) */
+void snd_seq_timer_delete(struct snd_seq_timer **tmr);
+
+/* */
+static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
+					     unsigned long resolution)
+{
+	if (tick->resolution > 0) {
+		tick->fraction += resolution;
+		tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
+		tick->fraction %= tick->resolution;
+	}
+}
+
+
+/* compare timestamp between events */
+/* return 1 if a >= b; otherwise return 0 */
+static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
+{
+	/* compare ticks */
+	return (*a >= *b);
+}
+
+static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
+{
+	/* compare real time */
+	if (a->tv_sec > b->tv_sec)
+		return 1;
+	if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
+		return 1;
+	return 0;
+}
+
+
+static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
+{
+	while (tm->tv_nsec >= 1000000000) {
+		/* roll-over */
+		tm->tv_nsec -= 1000000000;
+                tm->tv_sec++;
+        }
+}
+
+
+/* increment timestamp */
+static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
+{
+	tm->tv_sec  += inc->tv_sec;
+	tm->tv_nsec += inc->tv_nsec;
+	snd_seq_sanity_real_time(tm);
+}
+
+static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
+{
+	tm->tv_nsec  += nsec;
+	snd_seq_sanity_real_time(tm);
+}
+
+/* called by timer isr */
+struct snd_seq_queue;
+int snd_seq_timer_open(struct snd_seq_queue *q);
+int snd_seq_timer_close(struct snd_seq_queue *q);
+int snd_seq_timer_midi_open(struct snd_seq_queue *q);
+int snd_seq_timer_midi_close(struct snd_seq_queue *q);
+void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
+void snd_seq_timer_reset(struct snd_seq_timer *tmr);
+int snd_seq_timer_stop(struct snd_seq_timer *tmr);
+int snd_seq_timer_start(struct snd_seq_timer *tmr);
+int snd_seq_timer_continue(struct snd_seq_timer *tmr);
+int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
+int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq);
+int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
+int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
+int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);
+snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
+					       bool adjust_ktime);
+snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr);
+
+extern int seq_default_timer_class;
+extern int seq_default_timer_sclass;
+extern int seq_default_timer_card;
+extern int seq_default_timer_device;
+extern int seq_default_timer_subdevice;
+extern int seq_default_timer_resolution;
+
+#endif
diff --git a/sound/core/seq/seq_ump_client.c b/sound/core/seq/seq_ump_client.c
new file mode 100644
index 0000000000..2db371d799
--- /dev/null
+++ b/sound/core/seq/seq_ump_client.c
@@ -0,0 +1,562 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* ALSA sequencer binding for UMP device */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <asm/byteorder.h>
+#include <sound/core.h>
+#include <sound/ump.h>
+#include <sound/seq_kernel.h>
+#include <sound/seq_device.h>
+#include "seq_clientmgr.h"
+#include "seq_system.h"
+
+struct seq_ump_client;
+struct seq_ump_group;
+
+enum {
+	STR_IN = SNDRV_RAWMIDI_STREAM_INPUT,
+	STR_OUT = SNDRV_RAWMIDI_STREAM_OUTPUT
+};
+
+/* object per UMP group; corresponding to a sequencer port */
+struct seq_ump_group {
+	int group;			/* group index (0-based) */
+	unsigned int dir_bits;		/* directions */
+	bool active;			/* activeness */
+	char name[64];			/* seq port name */
+};
+
+/* context for UMP input parsing, per EP */
+struct seq_ump_input_buffer {
+	unsigned char len;		/* total length in words */
+	unsigned char pending;		/* pending words */
+	unsigned char type;		/* parsed UMP packet type */
+	unsigned char group;		/* parsed UMP packet group */
+	u32 buf[4];			/* incoming UMP packet */
+};
+
+/* sequencer client, per UMP EP (rawmidi) */
+struct seq_ump_client {
+	struct snd_ump_endpoint *ump;	/* assigned endpoint */
+	int seq_client;			/* sequencer client id */
+	int opened[2];			/* current opens for each direction */
+	struct snd_rawmidi_file out_rfile; /* rawmidi for output */
+	struct seq_ump_input_buffer input; /* input parser context */
+	struct seq_ump_group groups[SNDRV_UMP_MAX_GROUPS]; /* table of groups */
+	void *ump_info[SNDRV_UMP_MAX_BLOCKS + 1]; /* shadow of seq client ump_info */
+	struct work_struct group_notify_work; /* FB change notification */
+};
+
+/* number of 32bit words for each UMP message type */
+static unsigned char ump_packet_words[0x10] = {
+	1, 1, 1, 2, 2, 4, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4
+};
+
+/* conversion between UMP group and seq port;
+ * assume the port number is equal with UMP group number (1-based)
+ */
+static unsigned char ump_group_to_seq_port(unsigned char group)
+{
+	return group + 1;
+}
+
+/* process the incoming rawmidi stream */
+static void seq_ump_input_receive(struct snd_ump_endpoint *ump,
+				  const u32 *val, int words)
+{
+	struct seq_ump_client *client = ump->seq_client;
+	struct snd_seq_ump_event ev = {};
+
+	if (!client->opened[STR_IN])
+		return;
+
+	if (ump_is_groupless_msg(ump_message_type(*val)))
+		ev.source.port = 0; /* UMP EP port */
+	else
+		ev.source.port = ump_group_to_seq_port(ump_message_group(*val));
+	ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+	ev.flags = SNDRV_SEQ_EVENT_UMP;
+	memcpy(ev.ump, val, words << 2);
+	snd_seq_kernel_client_dispatch(client->seq_client,
+				       (struct snd_seq_event *)&ev,
+				       true, 0);
+}
+
+/* process an input sequencer event; only deal with UMP types */
+static int seq_ump_process_event(struct snd_seq_event *ev, int direct,
+				 void *private_data, int atomic, int hop)
+{
+	struct seq_ump_client *client = private_data;
+	struct snd_rawmidi_substream *substream;
+	struct snd_seq_ump_event *ump_ev;
+	unsigned char type;
+	int len;
+
+	substream = client->out_rfile.output;
+	if (!substream)
+		return -ENODEV;
+	if (!snd_seq_ev_is_ump(ev))
+		return 0; /* invalid event, skip */
+	ump_ev = (struct snd_seq_ump_event *)ev;
+	type = ump_message_type(ump_ev->ump[0]);
+	len = ump_packet_words[type];
+	if (len > 4)
+		return 0; // invalid - skip
+	snd_rawmidi_kernel_write(substream, ev->data.raw8.d, len << 2);
+	return 0;
+}
+
+/* open the rawmidi */
+static int seq_ump_client_open(struct seq_ump_client *client, int dir)
+{
+	struct snd_ump_endpoint *ump = client->ump;
+	int err = 0;
+
+	mutex_lock(&ump->open_mutex);
+	if (dir == STR_OUT && !client->opened[dir]) {
+		err = snd_rawmidi_kernel_open(&ump->core, 0,
+					      SNDRV_RAWMIDI_LFLG_OUTPUT |
+					      SNDRV_RAWMIDI_LFLG_APPEND,
+					      &client->out_rfile);
+		if (err < 0)
+			goto unlock;
+	}
+	client->opened[dir]++;
+ unlock:
+	mutex_unlock(&ump->open_mutex);
+	return err;
+}
+
+/* close the rawmidi */
+static int seq_ump_client_close(struct seq_ump_client *client, int dir)
+{
+	struct snd_ump_endpoint *ump = client->ump;
+
+	mutex_lock(&ump->open_mutex);
+	if (!--client->opened[dir])
+		if (dir == STR_OUT)
+			snd_rawmidi_kernel_release(&client->out_rfile);
+	mutex_unlock(&ump->open_mutex);
+	return 0;
+}
+
+/* sequencer subscription ops for each client */
+static int seq_ump_subscribe(void *pdata, struct snd_seq_port_subscribe *info)
+{
+	struct seq_ump_client *client = pdata;
+
+	return seq_ump_client_open(client, STR_IN);
+}
+
+static int seq_ump_unsubscribe(void *pdata, struct snd_seq_port_subscribe *info)
+{
+	struct seq_ump_client *client = pdata;
+
+	return seq_ump_client_close(client, STR_IN);
+}
+
+static int seq_ump_use(void *pdata, struct snd_seq_port_subscribe *info)
+{
+	struct seq_ump_client *client = pdata;
+
+	return seq_ump_client_open(client, STR_OUT);
+}
+
+static int seq_ump_unuse(void *pdata, struct snd_seq_port_subscribe *info)
+{
+	struct seq_ump_client *client = pdata;
+
+	return seq_ump_client_close(client, STR_OUT);
+}
+
+/* fill port_info from the given UMP EP and group info */
+static void fill_port_info(struct snd_seq_port_info *port,
+			   struct seq_ump_client *client,
+			   struct seq_ump_group *group)
+{
+	unsigned int rawmidi_info = client->ump->core.info_flags;
+
+	port->addr.client = client->seq_client;
+	port->addr.port = ump_group_to_seq_port(group->group);
+	port->capability = 0;
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT)
+		port->capability |= SNDRV_SEQ_PORT_CAP_WRITE |
+			SNDRV_SEQ_PORT_CAP_SYNC_WRITE |
+			SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT)
+		port->capability |= SNDRV_SEQ_PORT_CAP_READ |
+			SNDRV_SEQ_PORT_CAP_SYNC_READ |
+			SNDRV_SEQ_PORT_CAP_SUBS_READ;
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_DUPLEX)
+		port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+	if (group->dir_bits & (1 << STR_IN))
+		port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+	if (group->dir_bits & (1 << STR_OUT))
+		port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
+	port->ump_group = group->group + 1;
+	if (!group->active)
+		port->capability |= SNDRV_SEQ_PORT_CAP_INACTIVE;
+	port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+		SNDRV_SEQ_PORT_TYPE_MIDI_UMP |
+		SNDRV_SEQ_PORT_TYPE_HARDWARE |
+		SNDRV_SEQ_PORT_TYPE_PORT;
+	port->midi_channels = 16;
+	if (*group->name)
+		snprintf(port->name, sizeof(port->name), "Group %d (%.53s)",
+			 group->group + 1, group->name);
+	else
+		sprintf(port->name, "Group %d", group->group + 1);
+}
+
+/* create a new sequencer port per UMP group */
+static int seq_ump_group_init(struct seq_ump_client *client, int group_index)
+{
+	struct seq_ump_group *group = &client->groups[group_index];
+	struct snd_seq_port_info *port;
+	struct snd_seq_port_callback pcallbacks;
+	int err;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	fill_port_info(port, client, group);
+	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+	memset(&pcallbacks, 0, sizeof(pcallbacks));
+	pcallbacks.owner = THIS_MODULE;
+	pcallbacks.private_data = client;
+	pcallbacks.subscribe = seq_ump_subscribe;
+	pcallbacks.unsubscribe = seq_ump_unsubscribe;
+	pcallbacks.use = seq_ump_use;
+	pcallbacks.unuse = seq_ump_unuse;
+	pcallbacks.event_input = seq_ump_process_event;
+	port->kernel = &pcallbacks;
+	err = snd_seq_kernel_client_ctl(client->seq_client,
+					SNDRV_SEQ_IOCTL_CREATE_PORT,
+					port);
+ error:
+	kfree(port);
+	return err;
+}
+
+/* update the sequencer ports; called from notify_fb_change callback */
+static void update_port_infos(struct seq_ump_client *client)
+{
+	struct snd_seq_port_info *old, *new;
+	int i, err;
+
+	old = kzalloc(sizeof(*old), GFP_KERNEL);
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!old || !new)
+		goto error;
+
+	for (i = 0; i < SNDRV_UMP_MAX_GROUPS; i++) {
+		old->addr.client = client->seq_client;
+		old->addr.port = i;
+		err = snd_seq_kernel_client_ctl(client->seq_client,
+						SNDRV_SEQ_IOCTL_GET_PORT_INFO,
+						old);
+		if (err < 0)
+			goto error;
+		fill_port_info(new, client, &client->groups[i]);
+		if (old->capability == new->capability &&
+		    !strcmp(old->name, new->name))
+			continue;
+		err = snd_seq_kernel_client_ctl(client->seq_client,
+						SNDRV_SEQ_IOCTL_SET_PORT_INFO,
+						new);
+		if (err < 0)
+			goto error;
+		/* notify to system port */
+		snd_seq_system_client_ev_port_change(client->seq_client, i);
+	}
+ error:
+	kfree(new);
+	kfree(old);
+}
+
+/* update dir_bits and active flag for all groups in the client */
+static void update_group_attrs(struct seq_ump_client *client)
+{
+	struct snd_ump_block *fb;
+	struct seq_ump_group *group;
+	int i;
+
+	for (i = 0; i < SNDRV_UMP_MAX_GROUPS; i++) {
+		group = &client->groups[i];
+		*group->name = 0;
+		group->dir_bits = 0;
+		group->active = 0;
+		group->group = i;
+	}
+
+	list_for_each_entry(fb, &client->ump->block_list, list) {
+		if (fb->info.first_group + fb->info.num_groups > SNDRV_UMP_MAX_GROUPS)
+			break;
+		group = &client->groups[fb->info.first_group];
+		for (i = 0; i < fb->info.num_groups; i++, group++) {
+			if (fb->info.active)
+				group->active = 1;
+			switch (fb->info.direction) {
+			case SNDRV_UMP_DIR_INPUT:
+				group->dir_bits |= (1 << STR_IN);
+				break;
+			case SNDRV_UMP_DIR_OUTPUT:
+				group->dir_bits |= (1 << STR_OUT);
+				break;
+			case SNDRV_UMP_DIR_BIDIRECTION:
+				group->dir_bits |= (1 << STR_OUT) | (1 << STR_IN);
+				break;
+			}
+			if (!*fb->info.name)
+				continue;
+			if (!*group->name) {
+				/* store the first matching name */
+				strscpy(group->name, fb->info.name,
+					sizeof(group->name));
+			} else {
+				/* when overlapping, concat names */
+				strlcat(group->name, ", ", sizeof(group->name));
+				strlcat(group->name, fb->info.name,
+					sizeof(group->name));
+			}
+		}
+	}
+}
+
+/* create a UMP Endpoint port */
+static int create_ump_endpoint_port(struct seq_ump_client *client)
+{
+	struct snd_seq_port_info *port;
+	struct snd_seq_port_callback pcallbacks;
+	unsigned int rawmidi_info = client->ump->core.info_flags;
+	int err;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	port->addr.client = client->seq_client;
+	port->addr.port = 0; /* fixed */
+	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+	port->capability = SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT;
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT) {
+		port->capability |= SNDRV_SEQ_PORT_CAP_READ |
+			SNDRV_SEQ_PORT_CAP_SYNC_READ |
+			SNDRV_SEQ_PORT_CAP_SUBS_READ;
+		port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
+	}
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT) {
+		port->capability |= SNDRV_SEQ_PORT_CAP_WRITE |
+			SNDRV_SEQ_PORT_CAP_SYNC_WRITE |
+			SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+		port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
+	}
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_DUPLEX)
+		port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+	port->ump_group = 0; /* no associated group, no conversion */
+	port->type = SNDRV_SEQ_PORT_TYPE_MIDI_UMP |
+		SNDRV_SEQ_PORT_TYPE_HARDWARE |
+		SNDRV_SEQ_PORT_TYPE_PORT;
+	port->midi_channels = 16;
+	strcpy(port->name, "MIDI 2.0");
+	memset(&pcallbacks, 0, sizeof(pcallbacks));
+	pcallbacks.owner = THIS_MODULE;
+	pcallbacks.private_data = client;
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT) {
+		pcallbacks.subscribe = seq_ump_subscribe;
+		pcallbacks.unsubscribe = seq_ump_unsubscribe;
+	}
+	if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT) {
+		pcallbacks.use = seq_ump_use;
+		pcallbacks.unuse = seq_ump_unuse;
+		pcallbacks.event_input = seq_ump_process_event;
+	}
+	port->kernel = &pcallbacks;
+	err = snd_seq_kernel_client_ctl(client->seq_client,
+					SNDRV_SEQ_IOCTL_CREATE_PORT,
+					port);
+	kfree(port);
+	return err;
+}
+
+/* release the client resources */
+static void seq_ump_client_free(struct seq_ump_client *client)
+{
+	cancel_work_sync(&client->group_notify_work);
+
+	if (client->seq_client >= 0)
+		snd_seq_delete_kernel_client(client->seq_client);
+
+	client->ump->seq_ops = NULL;
+	client->ump->seq_client = NULL;
+
+	kfree(client);
+}
+
+/* update the MIDI version for the given client */
+static void setup_client_midi_version(struct seq_ump_client *client)
+{
+	struct snd_seq_client *cptr;
+
+	cptr = snd_seq_kernel_client_get(client->seq_client);
+	if (!cptr)
+		return;
+	if (client->ump->info.protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI2)
+		cptr->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_2_0;
+	else
+		cptr->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_1_0;
+	snd_seq_kernel_client_put(cptr);
+}
+
+/* set up client's group_filter bitmap */
+static void setup_client_group_filter(struct seq_ump_client *client)
+{
+	struct snd_seq_client *cptr;
+	unsigned int filter;
+	int p;
+
+	cptr = snd_seq_kernel_client_get(client->seq_client);
+	if (!cptr)
+		return;
+	filter = ~(1U << 0); /* always allow groupless messages */
+	for (p = 0; p < SNDRV_UMP_MAX_GROUPS; p++) {
+		if (client->groups[p].active)
+			filter &= ~(1U << (p + 1));
+	}
+	cptr->group_filter = filter;
+	snd_seq_kernel_client_put(cptr);
+}
+
+/* UMP group change notification */
+static void handle_group_notify(struct work_struct *work)
+{
+	struct seq_ump_client *client =
+		container_of(work, struct seq_ump_client, group_notify_work);
+
+	update_group_attrs(client);
+	update_port_infos(client);
+	setup_client_group_filter(client);
+}
+
+/* UMP FB change notification */
+static int seq_ump_notify_fb_change(struct snd_ump_endpoint *ump,
+				    struct snd_ump_block *fb)
+{
+	struct seq_ump_client *client = ump->seq_client;
+
+	if (!client)
+		return -ENODEV;
+	schedule_work(&client->group_notify_work);
+	return 0;
+}
+
+/* UMP protocol change notification; just update the midi_version field */
+static int seq_ump_switch_protocol(struct snd_ump_endpoint *ump)
+{
+	if (!ump->seq_client)
+		return -ENODEV;
+	setup_client_midi_version(ump->seq_client);
+	return 0;
+}
+
+static const struct snd_seq_ump_ops seq_ump_ops = {
+	.input_receive = seq_ump_input_receive,
+	.notify_fb_change = seq_ump_notify_fb_change,
+	.switch_protocol = seq_ump_switch_protocol,
+};
+
+/* create a sequencer client and ports for the given UMP endpoint */
+static int snd_seq_ump_probe(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	struct snd_ump_endpoint *ump = dev->private_data;
+	struct snd_card *card = dev->card;
+	struct seq_ump_client *client;
+	struct snd_ump_block *fb;
+	struct snd_seq_client *cptr;
+	int p, err;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return -ENOMEM;
+
+	INIT_WORK(&client->group_notify_work, handle_group_notify);
+	client->ump = ump;
+
+	client->seq_client =
+		snd_seq_create_kernel_client(card, ump->core.device,
+					     ump->core.name);
+	if (client->seq_client < 0) {
+		err = client->seq_client;
+		goto error;
+	}
+
+	client->ump_info[0] = &ump->info;
+	list_for_each_entry(fb, &ump->block_list, list)
+		client->ump_info[fb->info.block_id + 1] = &fb->info;
+
+	setup_client_midi_version(client);
+	update_group_attrs(client);
+
+	for (p = 0; p < SNDRV_UMP_MAX_GROUPS; p++) {
+		err = seq_ump_group_init(client, p);
+		if (err < 0)
+			goto error;
+	}
+
+	setup_client_group_filter(client);
+
+	err = create_ump_endpoint_port(client);
+	if (err < 0)
+		goto error;
+
+	cptr = snd_seq_kernel_client_get(client->seq_client);
+	if (!cptr) {
+		err = -EINVAL;
+		goto error;
+	}
+	cptr->ump_info = client->ump_info;
+	snd_seq_kernel_client_put(cptr);
+
+	ump->seq_client = client;
+	ump->seq_ops = &seq_ump_ops;
+	return 0;
+
+ error:
+	seq_ump_client_free(client);
+	return err;
+}
+
+/* remove a sequencer client */
+static int snd_seq_ump_remove(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	struct snd_ump_endpoint *ump = dev->private_data;
+
+	if (ump->seq_client)
+		seq_ump_client_free(ump->seq_client);
+	return 0;
+}
+
+static struct snd_seq_driver seq_ump_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.probe = snd_seq_ump_probe,
+		.remove = snd_seq_ump_remove,
+	},
+	.id = SNDRV_SEQ_DEV_ID_UMP,
+	.argsize = 0,
+};
+
+module_snd_seq_driver(seq_ump_driver);
+
+MODULE_DESCRIPTION("ALSA sequencer client for UMP rawmidi");
+MODULE_LICENSE("GPL");
diff --git a/sound/core/seq/seq_ump_convert.c b/sound/core/seq/seq_ump_convert.c
new file mode 100644
index 0000000000..b141024830
--- /dev/null
+++ b/sound/core/seq/seq_ump_convert.c
@@ -0,0 +1,1208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ALSA sequencer event conversion between UMP and legacy clients
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <sound/core.h>
+#include <sound/ump.h>
+#include <sound/ump_msg.h>
+#include "seq_ump_convert.h"
+
+/*
+ * Upgrade / downgrade value bits
+ */
+static u8 downscale_32_to_7bit(u32 src)
+{
+	return src >> 25;
+}
+
+static u16 downscale_32_to_14bit(u32 src)
+{
+	return src >> 18;
+}
+
+static u8 downscale_16_to_7bit(u16 src)
+{
+	return src >> 9;
+}
+
+static u16 upscale_7_to_16bit(u8 src)
+{
+	u16 val, repeat;
+
+	val = (u16)src << 9;
+	if (src <= 0x40)
+		return val;
+	repeat = src & 0x3f;
+	return val | (repeat << 3) | (repeat >> 3);
+}
+
+static u32 upscale_7_to_32bit(u8 src)
+{
+	u32 val, repeat;
+
+	val = src << 25;
+	if (src <= 0x40)
+		return val;
+	repeat = src & 0x3f;
+	return val | (repeat << 19) | (repeat << 13) |
+		(repeat << 7) | (repeat << 1) | (repeat >> 5);
+}
+
+static u32 upscale_14_to_32bit(u16 src)
+{
+	u32 val, repeat;
+
+	val = src << 18;
+	if (src <= 0x2000)
+		return val;
+	repeat = src & 0x1fff;
+	return val | (repeat << 5) | (repeat >> 8);
+}
+
+static unsigned char get_ump_group(struct snd_seq_client_port *port)
+{
+	return port->ump_group ? (port->ump_group - 1) : 0;
+}
+
+/* create a UMP header */
+#define make_raw_ump(port, type) \
+	ump_compose(type, get_ump_group(port), 0, 0)
+
+/*
+ * UMP -> MIDI1 sequencer event
+ */
+
+/* MIDI 1.0 CVM */
+
+/* encode note event */
+static void ump_midi1_to_note_ev(const union snd_ump_midi1_msg *val,
+				 struct snd_seq_event *ev)
+{
+	ev->data.note.channel = val->note.channel;
+	ev->data.note.note = val->note.note;
+	ev->data.note.velocity = val->note.velocity;
+}
+
+/* encode one parameter controls */
+static void ump_midi1_to_ctrl_ev(const union snd_ump_midi1_msg *val,
+				 struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->caf.channel;
+	ev->data.control.value = val->caf.data;
+}
+
+/* encode pitch wheel change */
+static void ump_midi1_to_pitchbend_ev(const union snd_ump_midi1_msg *val,
+				      struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->pb.channel;
+	ev->data.control.value = (val->pb.data_msb << 7) | val->pb.data_lsb;
+	ev->data.control.value -= 8192;
+}
+
+/* encode midi control change */
+static void ump_midi1_to_cc_ev(const union snd_ump_midi1_msg *val,
+			       struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->cc.channel;
+	ev->data.control.param = val->cc.index;
+	ev->data.control.value = val->cc.data;
+}
+
+/* Encoding MIDI 1.0 UMP packet */
+struct seq_ump_midi1_to_ev {
+	int seq_type;
+	void (*encode)(const union snd_ump_midi1_msg *val, struct snd_seq_event *ev);
+};
+
+/* Encoders for MIDI1 status 0x80-0xe0 */
+static struct seq_ump_midi1_to_ev midi1_msg_encoders[] = {
+	{SNDRV_SEQ_EVENT_NOTEOFF,	ump_midi1_to_note_ev},	/* 0x80 */
+	{SNDRV_SEQ_EVENT_NOTEON,	ump_midi1_to_note_ev},	/* 0x90 */
+	{SNDRV_SEQ_EVENT_KEYPRESS,	ump_midi1_to_note_ev},	/* 0xa0 */
+	{SNDRV_SEQ_EVENT_CONTROLLER,	ump_midi1_to_cc_ev},	/* 0xb0 */
+	{SNDRV_SEQ_EVENT_PGMCHANGE,	ump_midi1_to_ctrl_ev},	/* 0xc0 */
+	{SNDRV_SEQ_EVENT_CHANPRESS,	ump_midi1_to_ctrl_ev},	/* 0xd0 */
+	{SNDRV_SEQ_EVENT_PITCHBEND,	ump_midi1_to_pitchbend_ev}, /* 0xe0 */
+};
+
+static int cvt_ump_midi1_to_event(const union snd_ump_midi1_msg *val,
+				  struct snd_seq_event *ev)
+{
+	unsigned char status = val->note.status;
+
+	if (status < 0x8 || status > 0xe)
+		return 0; /* invalid - skip */
+	status -= 8;
+	ev->type = midi1_msg_encoders[status].seq_type;
+	ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+	midi1_msg_encoders[status].encode(val, ev);
+	return 1;
+}
+
+/* MIDI System message */
+
+/* encode one parameter value*/
+static void ump_system_to_one_param_ev(const union snd_ump_midi1_msg *val,
+				       struct snd_seq_event *ev)
+{
+	ev->data.control.value = val->system.parm1;
+}
+
+/* encode song position */
+static void ump_system_to_songpos_ev(const union snd_ump_midi1_msg *val,
+				     struct snd_seq_event *ev)
+{
+	ev->data.control.value = (val->system.parm1 << 7) | val->system.parm2;
+}
+
+/* Encoders for 0xf0 - 0xff */
+static struct seq_ump_midi1_to_ev system_msg_encoders[] = {
+	{SNDRV_SEQ_EVENT_NONE,		NULL},	 /* 0xf0 */
+	{SNDRV_SEQ_EVENT_QFRAME,	ump_system_to_one_param_ev}, /* 0xf1 */
+	{SNDRV_SEQ_EVENT_SONGPOS,	ump_system_to_songpos_ev}, /* 0xf2 */
+	{SNDRV_SEQ_EVENT_SONGSEL,	ump_system_to_one_param_ev}, /* 0xf3 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL}, /* 0xf4 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL}, /* 0xf5 */
+	{SNDRV_SEQ_EVENT_TUNE_REQUEST,	NULL}, /* 0xf6 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL}, /* 0xf7 */
+	{SNDRV_SEQ_EVENT_CLOCK,		NULL}, /* 0xf8 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL}, /* 0xf9 */
+	{SNDRV_SEQ_EVENT_START,		NULL}, /* 0xfa */
+	{SNDRV_SEQ_EVENT_CONTINUE,	NULL}, /* 0xfb */
+	{SNDRV_SEQ_EVENT_STOP,		NULL}, /* 0xfc */
+	{SNDRV_SEQ_EVENT_NONE,		NULL}, /* 0xfd */
+	{SNDRV_SEQ_EVENT_SENSING,	NULL}, /* 0xfe */
+	{SNDRV_SEQ_EVENT_RESET,		NULL}, /* 0xff */
+};
+
+static int cvt_ump_system_to_event(const union snd_ump_midi1_msg *val,
+				   struct snd_seq_event *ev)
+{
+	unsigned char status = val->system.status;
+
+	if ((status & 0xf0) != UMP_MIDI1_MSG_REALTIME)
+		return 0; /* invalid status - skip */
+	status &= 0x0f;
+	ev->type = system_msg_encoders[status].seq_type;
+	ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+	if (ev->type == SNDRV_SEQ_EVENT_NONE)
+		return 0;
+	if (system_msg_encoders[status].encode)
+		system_msg_encoders[status].encode(val, ev);
+	return 1;
+}
+
+/* MIDI 2.0 CVM */
+
+/* encode note event */
+static int ump_midi2_to_note_ev(const union snd_ump_midi2_msg *val,
+				struct snd_seq_event *ev)
+{
+	ev->data.note.channel = val->note.channel;
+	ev->data.note.note = val->note.note;
+	ev->data.note.velocity = downscale_16_to_7bit(val->note.velocity);
+	/* correct note-on velocity 0 to 1;
+	 * it's no longer equivalent as not-off for MIDI 2.0
+	 */
+	if (ev->type == SNDRV_SEQ_EVENT_NOTEON &&
+	    !ev->data.note.velocity)
+		ev->data.note.velocity = 1;
+	return 1;
+}
+
+/* encode pitch wheel change */
+static int ump_midi2_to_pitchbend_ev(const union snd_ump_midi2_msg *val,
+				     struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->pb.channel;
+	ev->data.control.value = downscale_32_to_14bit(val->pb.data);
+	ev->data.control.value -= 8192;
+	return 1;
+}
+
+/* encode midi control change */
+static int ump_midi2_to_cc_ev(const union snd_ump_midi2_msg *val,
+			      struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->cc.channel;
+	ev->data.control.param = val->cc.index;
+	ev->data.control.value = downscale_32_to_7bit(val->cc.data);
+	return 1;
+}
+
+/* encode midi program change */
+static int ump_midi2_to_pgm_ev(const union snd_ump_midi2_msg *val,
+			       struct snd_seq_event *ev)
+{
+	int size = 1;
+
+	ev->data.control.channel = val->pg.channel;
+	if (val->pg.bank_valid) {
+		ev->type = SNDRV_SEQ_EVENT_CONTROL14;
+		ev->data.control.param = UMP_CC_BANK_SELECT;
+		ev->data.control.value = (val->pg.bank_msb << 7) | val->pg.bank_lsb;
+		ev[1] = ev[0];
+		ev++;
+		ev->type = SNDRV_SEQ_EVENT_PGMCHANGE;
+		size = 2;
+	}
+	ev->data.control.value = val->pg.program;
+	return size;
+}
+
+/* encode one parameter controls */
+static int ump_midi2_to_ctrl_ev(const union snd_ump_midi2_msg *val,
+				struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->caf.channel;
+	ev->data.control.value = downscale_32_to_7bit(val->caf.data);
+	return 1;
+}
+
+/* encode RPN/NRPN */
+static int ump_midi2_to_rpn_ev(const union snd_ump_midi2_msg *val,
+			       struct snd_seq_event *ev)
+{
+	ev->data.control.channel = val->rpn.channel;
+	ev->data.control.param = (val->rpn.bank << 7) | val->rpn.index;
+	ev->data.control.value = downscale_32_to_14bit(val->rpn.data);
+	return 1;
+}
+
+/* Encoding MIDI 2.0 UMP Packet */
+struct seq_ump_midi2_to_ev {
+	int seq_type;
+	int (*encode)(const union snd_ump_midi2_msg *val, struct snd_seq_event *ev);
+};
+
+/* Encoders for MIDI2 status 0x00-0xf0 */
+static struct seq_ump_midi2_to_ev midi2_msg_encoders[] = {
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0x00 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0x10 */
+	{SNDRV_SEQ_EVENT_REGPARAM,	ump_midi2_to_rpn_ev},	/* 0x20 */
+	{SNDRV_SEQ_EVENT_NONREGPARAM,	ump_midi2_to_rpn_ev},	/* 0x30 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0x40 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0x50 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0x60 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0x70 */
+	{SNDRV_SEQ_EVENT_NOTEOFF,	ump_midi2_to_note_ev},	/* 0x80 */
+	{SNDRV_SEQ_EVENT_NOTEON,	ump_midi2_to_note_ev},	/* 0x90 */
+	{SNDRV_SEQ_EVENT_KEYPRESS,	ump_midi2_to_note_ev},	/* 0xa0 */
+	{SNDRV_SEQ_EVENT_CONTROLLER,	ump_midi2_to_cc_ev},	/* 0xb0 */
+	{SNDRV_SEQ_EVENT_PGMCHANGE,	ump_midi2_to_pgm_ev},	/* 0xc0 */
+	{SNDRV_SEQ_EVENT_CHANPRESS,	ump_midi2_to_ctrl_ev},	/* 0xd0 */
+	{SNDRV_SEQ_EVENT_PITCHBEND,	ump_midi2_to_pitchbend_ev}, /* 0xe0 */
+	{SNDRV_SEQ_EVENT_NONE,		NULL},			/* 0xf0 */
+};
+
+static int cvt_ump_midi2_to_event(const union snd_ump_midi2_msg *val,
+				  struct snd_seq_event *ev)
+{
+	unsigned char status = val->note.status;
+
+	ev->type = midi2_msg_encoders[status].seq_type;
+	if (ev->type == SNDRV_SEQ_EVENT_NONE)
+		return 0; /* skip */
+	ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+	return midi2_msg_encoders[status].encode(val, ev);
+}
+
+/* parse and compose for a sysex var-length event */
+static int cvt_ump_sysex7_to_event(const u32 *data, unsigned char *buf,
+				   struct snd_seq_event *ev)
+{
+	unsigned char status;
+	unsigned char bytes;
+	u32 val;
+	int size = 0;
+
+	val = data[0];
+	status = ump_sysex_message_status(val);
+	bytes = ump_sysex_message_length(val);
+	if (bytes > 6)
+		return 0; // skip
+
+	if (status == UMP_SYSEX_STATUS_SINGLE ||
+	    status == UMP_SYSEX_STATUS_START) {
+		buf[0] = UMP_MIDI1_MSG_SYSEX_START;
+		size = 1;
+	}
+
+	if (bytes > 0)
+		buf[size++] = (val >> 8) & 0x7f;
+	if (bytes > 1)
+		buf[size++] = val & 0x7f;
+	val = data[1];
+	if (bytes > 2)
+		buf[size++] = (val >> 24) & 0x7f;
+	if (bytes > 3)
+		buf[size++] = (val >> 16) & 0x7f;
+	if (bytes > 4)
+		buf[size++] = (val >> 8) & 0x7f;
+	if (bytes > 5)
+		buf[size++] = val & 0x7f;
+
+	if (status == UMP_SYSEX_STATUS_SINGLE ||
+	    status == UMP_SYSEX_STATUS_END)
+		buf[size++] = UMP_MIDI1_MSG_SYSEX_END;
+
+	ev->type = SNDRV_SEQ_EVENT_SYSEX;
+	ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
+	ev->data.ext.len = size;
+	ev->data.ext.ptr = buf;
+	return 1;
+}
+
+/* convert UMP packet from MIDI 1.0 to MIDI 2.0 and deliver it */
+static int cvt_ump_midi1_to_midi2(struct snd_seq_client *dest,
+				  struct snd_seq_client_port *dest_port,
+				  struct snd_seq_event *__event,
+				  int atomic, int hop)
+{
+	struct snd_seq_ump_event *event = (struct snd_seq_ump_event *)__event;
+	struct snd_seq_ump_event ev_cvt;
+	const union snd_ump_midi1_msg *midi1 = (const union snd_ump_midi1_msg *)event->ump;
+	union snd_ump_midi2_msg *midi2 = (union snd_ump_midi2_msg *)ev_cvt.ump;
+
+	ev_cvt = *event;
+	memset(&ev_cvt.ump, 0, sizeof(ev_cvt.ump));
+
+	midi2->note.type = UMP_MSG_TYPE_MIDI2_CHANNEL_VOICE;
+	midi2->note.group = midi1->note.group;
+	midi2->note.status = midi1->note.status;
+	midi2->note.channel = midi1->note.channel;
+	switch (midi1->note.status) {
+	case UMP_MSG_STATUS_NOTE_ON:
+	case UMP_MSG_STATUS_NOTE_OFF:
+		midi2->note.note = midi1->note.note;
+		midi2->note.velocity = upscale_7_to_16bit(midi1->note.velocity);
+		break;
+	case UMP_MSG_STATUS_POLY_PRESSURE:
+		midi2->paf.note = midi1->paf.note;
+		midi2->paf.data = upscale_7_to_32bit(midi1->paf.data);
+		break;
+	case UMP_MSG_STATUS_CC:
+		midi2->cc.index = midi1->cc.index;
+		midi2->cc.data = upscale_7_to_32bit(midi1->cc.data);
+		break;
+	case UMP_MSG_STATUS_PROGRAM:
+		midi2->pg.program = midi1->pg.program;
+		break;
+	case UMP_MSG_STATUS_CHANNEL_PRESSURE:
+		midi2->caf.data = upscale_7_to_32bit(midi1->caf.data);
+		break;
+	case UMP_MSG_STATUS_PITCH_BEND:
+		midi2->pb.data = upscale_14_to_32bit((midi1->pb.data_msb << 7) |
+						     midi1->pb.data_lsb);
+		break;
+	default:
+		return 0;
+	}
+
+	return __snd_seq_deliver_single_event(dest, dest_port,
+					      (struct snd_seq_event *)&ev_cvt,
+					      atomic, hop);
+}
+
+/* convert UMP packet from MIDI 2.0 to MIDI 1.0 and deliver it */
+static int cvt_ump_midi2_to_midi1(struct snd_seq_client *dest,
+				  struct snd_seq_client_port *dest_port,
+				  struct snd_seq_event *__event,
+				  int atomic, int hop)
+{
+	struct snd_seq_ump_event *event = (struct snd_seq_ump_event *)__event;
+	struct snd_seq_ump_event ev_cvt;
+	union snd_ump_midi1_msg *midi1 = (union snd_ump_midi1_msg *)ev_cvt.ump;
+	const union snd_ump_midi2_msg *midi2 = (const union snd_ump_midi2_msg *)event->ump;
+	u16 v;
+
+	ev_cvt = *event;
+	memset(&ev_cvt.ump, 0, sizeof(ev_cvt.ump));
+
+	midi1->note.type = UMP_MSG_TYPE_MIDI1_CHANNEL_VOICE;
+	midi1->note.group = midi2->note.group;
+	midi1->note.status = midi2->note.status;
+	midi1->note.channel = midi2->note.channel;
+	switch (midi2->note.status << 4) {
+	case UMP_MSG_STATUS_NOTE_ON:
+	case UMP_MSG_STATUS_NOTE_OFF:
+		midi1->note.note = midi2->note.note;
+		midi1->note.velocity = downscale_16_to_7bit(midi2->note.velocity);
+		break;
+	case UMP_MSG_STATUS_POLY_PRESSURE:
+		midi1->paf.note = midi2->paf.note;
+		midi1->paf.data = downscale_32_to_7bit(midi2->paf.data);
+		break;
+	case UMP_MSG_STATUS_CC:
+		midi1->cc.index = midi2->cc.index;
+		midi1->cc.data = downscale_32_to_7bit(midi2->cc.data);
+		break;
+	case UMP_MSG_STATUS_PROGRAM:
+		midi1->pg.program = midi2->pg.program;
+		break;
+	case UMP_MSG_STATUS_CHANNEL_PRESSURE:
+		midi1->caf.data = downscale_32_to_7bit(midi2->caf.data);
+		break;
+	case UMP_MSG_STATUS_PITCH_BEND:
+		v = downscale_32_to_14bit(midi2->pb.data);
+		midi1->pb.data_msb = v >> 7;
+		midi1->pb.data_lsb = v & 0x7f;
+		break;
+	default:
+		return 0;
+	}
+
+	return __snd_seq_deliver_single_event(dest, dest_port,
+					      (struct snd_seq_event *)&ev_cvt,
+					      atomic, hop);
+}
+
+/* convert UMP to a legacy ALSA seq event and deliver it */
+static int cvt_ump_to_any(struct snd_seq_client *dest,
+			  struct snd_seq_client_port *dest_port,
+			  struct snd_seq_event *event,
+			  unsigned char type,
+			  int atomic, int hop)
+{
+	struct snd_seq_event ev_cvt[2]; /* up to two events */
+	struct snd_seq_ump_event *ump_ev = (struct snd_seq_ump_event *)event;
+	/* use the second event as a temp buffer for saving stack usage */
+	unsigned char *sysex_buf = (unsigned char *)(ev_cvt + 1);
+	unsigned char flags = event->flags & ~SNDRV_SEQ_EVENT_UMP;
+	int i, len, err;
+
+	ev_cvt[0] = ev_cvt[1] = *event;
+	ev_cvt[0].flags = flags;
+	ev_cvt[1].flags = flags;
+	switch (type) {
+	case UMP_MSG_TYPE_SYSTEM:
+		len = cvt_ump_system_to_event((union snd_ump_midi1_msg *)ump_ev->ump,
+					      ev_cvt);
+		break;
+	case UMP_MSG_TYPE_MIDI1_CHANNEL_VOICE:
+		len = cvt_ump_midi1_to_event((union snd_ump_midi1_msg *)ump_ev->ump,
+					     ev_cvt);
+		break;
+	case UMP_MSG_TYPE_MIDI2_CHANNEL_VOICE:
+		len = cvt_ump_midi2_to_event((union snd_ump_midi2_msg *)ump_ev->ump,
+					     ev_cvt);
+		break;
+	case UMP_MSG_TYPE_DATA:
+		len = cvt_ump_sysex7_to_event(ump_ev->ump, sysex_buf, ev_cvt);
+		break;
+	default:
+		return 0;
+	}
+
+	for (i = 0; i < len; i++) {
+		err = __snd_seq_deliver_single_event(dest, dest_port,
+						     &ev_cvt[i], atomic, hop);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* Replace UMP group field with the destination and deliver */
+static int deliver_with_group_convert(struct snd_seq_client *dest,
+				      struct snd_seq_client_port *dest_port,
+				      struct snd_seq_ump_event *ump_ev,
+				      int atomic, int hop)
+{
+	struct snd_seq_ump_event ev = *ump_ev;
+
+	/* rewrite the group to the destination port */
+	ev.ump[0] &= ~(0xfU << 24);
+	/* fill with the new group; the dest_port->ump_group field is 1-based */
+	ev.ump[0] |= ((dest_port->ump_group - 1) << 24);
+
+	return __snd_seq_deliver_single_event(dest, dest_port,
+					      (struct snd_seq_event *)&ev,
+					      atomic, hop);
+}
+
+/* apply the UMP event filter; return true to skip the event */
+static bool ump_event_filtered(struct snd_seq_client *dest,
+			       const struct snd_seq_ump_event *ev)
+{
+	unsigned char group;
+
+	group = ump_message_group(ev->ump[0]);
+	if (ump_is_groupless_msg(ump_message_type(ev->ump[0])))
+		return dest->group_filter & (1U << 0);
+	/* check the bitmap for 1-based group number */
+	return dest->group_filter & (1U << (group + 1));
+}
+
+/* Convert from UMP packet and deliver */
+int snd_seq_deliver_from_ump(struct snd_seq_client *source,
+			     struct snd_seq_client *dest,
+			     struct snd_seq_client_port *dest_port,
+			     struct snd_seq_event *event,
+			     int atomic, int hop)
+{
+	struct snd_seq_ump_event *ump_ev = (struct snd_seq_ump_event *)event;
+	unsigned char type;
+
+	if (snd_seq_ev_is_variable(event))
+		return 0; // skip, no variable event for UMP, so far
+	if (ump_event_filtered(dest, ump_ev))
+		return 0; // skip if group filter is set and matching
+	type = ump_message_type(ump_ev->ump[0]);
+
+	if (snd_seq_client_is_ump(dest)) {
+		if (snd_seq_client_is_midi2(dest) &&
+		    type == UMP_MSG_TYPE_MIDI1_CHANNEL_VOICE)
+			return cvt_ump_midi1_to_midi2(dest, dest_port,
+						      event, atomic, hop);
+		else if (!snd_seq_client_is_midi2(dest) &&
+			 type == UMP_MSG_TYPE_MIDI2_CHANNEL_VOICE)
+			return cvt_ump_midi2_to_midi1(dest, dest_port,
+						      event, atomic, hop);
+		/* non-EP port and different group is set? */
+		if (dest_port->ump_group &&
+		    !ump_is_groupless_msg(type) &&
+		    ump_message_group(*ump_ev->ump) + 1 != dest_port->ump_group)
+			return deliver_with_group_convert(dest, dest_port,
+							  ump_ev, atomic, hop);
+		/* copy as-is */
+		return __snd_seq_deliver_single_event(dest, dest_port,
+						      event, atomic, hop);
+	}
+
+	return cvt_ump_to_any(dest, dest_port, event, type, atomic, hop);
+}
+
+/*
+ * MIDI1 sequencer event -> UMP conversion
+ */
+
+/* Conversion to UMP MIDI 1.0 */
+
+/* convert note on/off event to MIDI 1.0 UMP */
+static int note_ev_to_ump_midi1(const struct snd_seq_event *event,
+				struct snd_seq_client_port *dest_port,
+				union snd_ump_midi1_msg *data,
+				unsigned char status)
+{
+	if (!event->data.note.velocity)
+		status = UMP_MSG_STATUS_NOTE_OFF;
+	data->note.status = status;
+	data->note.channel = event->data.note.channel & 0x0f;
+	data->note.velocity = event->data.note.velocity & 0x7f;
+	data->note.note = event->data.note.note & 0x7f;
+	return 1;
+}
+
+/* convert CC event to MIDI 1.0 UMP */
+static int cc_ev_to_ump_midi1(const struct snd_seq_event *event,
+			      struct snd_seq_client_port *dest_port,
+			      union snd_ump_midi1_msg *data,
+			      unsigned char status)
+{
+	data->cc.status = status;
+	data->cc.channel = event->data.control.channel & 0x0f;
+	data->cc.index = event->data.control.param;
+	data->cc.data = event->data.control.value;
+	return 1;
+}
+
+/* convert one-parameter control event to MIDI 1.0 UMP */
+static int ctrl_ev_to_ump_midi1(const struct snd_seq_event *event,
+				struct snd_seq_client_port *dest_port,
+				union snd_ump_midi1_msg *data,
+				unsigned char status)
+{
+	data->caf.status = status;
+	data->caf.channel = event->data.control.channel & 0x0f;
+	data->caf.data = event->data.control.value & 0x7f;
+	return 1;
+}
+
+/* convert pitchbend event to MIDI 1.0 UMP */
+static int pitchbend_ev_to_ump_midi1(const struct snd_seq_event *event,
+				     struct snd_seq_client_port *dest_port,
+				     union snd_ump_midi1_msg *data,
+				     unsigned char status)
+{
+	int val = event->data.control.value + 8192;
+
+	val = clamp(val, 0, 0x3fff);
+	data->pb.status = status;
+	data->pb.channel = event->data.control.channel & 0x0f;
+	data->pb.data_msb = (val >> 7) & 0x7f;
+	data->pb.data_lsb = val & 0x7f;
+	return 1;
+}
+
+/* convert 14bit control event to MIDI 1.0 UMP; split to two events */
+static int ctrl14_ev_to_ump_midi1(const struct snd_seq_event *event,
+				  struct snd_seq_client_port *dest_port,
+				  union snd_ump_midi1_msg *data,
+				  unsigned char status)
+{
+	data->cc.status = UMP_MSG_STATUS_CC;
+	data->cc.channel = event->data.control.channel & 0x0f;
+	data->cc.index = event->data.control.param & 0x7f;
+	if (event->data.control.param < 0x20) {
+		data->cc.data = (event->data.control.value >> 7) & 0x7f;
+		data[1] = data[0];
+		data[1].cc.index = event->data.control.param | 0x20;
+		data[1].cc.data = event->data.control.value & 0x7f;
+		return 2;
+	}
+
+	data->cc.data = event->data.control.value & 0x7f;
+	return 1;
+}
+
+/* convert RPN/NRPN event to MIDI 1.0 UMP; split to four events */
+static int rpn_ev_to_ump_midi1(const struct snd_seq_event *event,
+			       struct snd_seq_client_port *dest_port,
+			       union snd_ump_midi1_msg *data,
+			       unsigned char status)
+{
+	bool is_rpn = (status == UMP_MSG_STATUS_RPN);
+
+	data->cc.status = UMP_MSG_STATUS_CC;
+	data->cc.channel = event->data.control.channel & 0x0f;
+	data[1] = data[2] = data[3] = data[0];
+
+	data[0].cc.index = is_rpn ? UMP_CC_RPN_MSB : UMP_CC_NRPN_MSB;
+	data[0].cc.data = (event->data.control.param >> 7) & 0x7f;
+	data[1].cc.index = is_rpn ? UMP_CC_RPN_LSB : UMP_CC_NRPN_LSB;
+	data[1].cc.data = event->data.control.param & 0x7f;
+	data[2].cc.index = UMP_CC_DATA;
+	data[2].cc.data = (event->data.control.value >> 7) & 0x7f;
+	data[3].cc.index = UMP_CC_DATA_LSB;
+	data[3].cc.data = event->data.control.value & 0x7f;
+	return 4;
+}
+
+/* convert system / RT message to UMP */
+static int system_ev_to_ump_midi1(const struct snd_seq_event *event,
+				  struct snd_seq_client_port *dest_port,
+				  union snd_ump_midi1_msg *data,
+				  unsigned char status)
+{
+	data->system.status = status;
+	return 1;
+}
+
+/* convert system / RT message with 1 parameter to UMP */
+static int system_1p_ev_to_ump_midi1(const struct snd_seq_event *event,
+				     struct snd_seq_client_port *dest_port,
+				     union snd_ump_midi1_msg *data,
+				     unsigned char status)
+{
+	data->system.status = status;
+	data->system.parm1 = event->data.control.value & 0x7f;
+	return 1;
+}
+
+/* convert system / RT message with two parameters to UMP */
+static int system_2p_ev_to_ump_midi1(const struct snd_seq_event *event,
+				     struct snd_seq_client_port *dest_port,
+				     union snd_ump_midi1_msg *data,
+				     unsigned char status)
+{
+	data->system.status = status;
+	data->system.parm1 = (event->data.control.value >> 7) & 0x7f;
+	data->system.parm2 = event->data.control.value & 0x7f;
+	return 1;
+}
+
+/* Conversion to UMP MIDI 2.0 */
+
+/* convert note on/off event to MIDI 2.0 UMP */
+static int note_ev_to_ump_midi2(const struct snd_seq_event *event,
+				struct snd_seq_client_port *dest_port,
+				union snd_ump_midi2_msg *data,
+				unsigned char status)
+{
+	if (!event->data.note.velocity)
+		status = UMP_MSG_STATUS_NOTE_OFF;
+	data->note.status = status;
+	data->note.channel = event->data.note.channel & 0x0f;
+	data->note.note = event->data.note.note & 0x7f;
+	data->note.velocity = upscale_7_to_16bit(event->data.note.velocity & 0x7f);
+	return 1;
+}
+
+/* convert PAF event to MIDI 2.0 UMP */
+static int paf_ev_to_ump_midi2(const struct snd_seq_event *event,
+			       struct snd_seq_client_port *dest_port,
+			       union snd_ump_midi2_msg *data,
+			       unsigned char status)
+{
+	data->paf.status = status;
+	data->paf.channel = event->data.note.channel & 0x0f;
+	data->paf.note = event->data.note.note & 0x7f;
+	data->paf.data = upscale_7_to_32bit(event->data.note.velocity & 0x7f);
+	return 1;
+}
+
+/* set up the MIDI2 RPN/NRPN packet data from the parsed info */
+static void fill_rpn(struct snd_seq_ump_midi2_bank *cc,
+		     union snd_ump_midi2_msg *data)
+{
+	if (cc->rpn_set) {
+		data->rpn.status = UMP_MSG_STATUS_RPN;
+		data->rpn.bank = cc->cc_rpn_msb;
+		data->rpn.index = cc->cc_rpn_lsb;
+		cc->rpn_set = 0;
+		cc->cc_rpn_msb = cc->cc_rpn_lsb = 0;
+	} else {
+		data->rpn.status = UMP_MSG_STATUS_NRPN;
+		data->rpn.bank = cc->cc_nrpn_msb;
+		data->rpn.index = cc->cc_nrpn_lsb;
+		cc->nrpn_set = 0;
+		cc->cc_nrpn_msb = cc->cc_nrpn_lsb = 0;
+	}
+	data->rpn.data = upscale_14_to_32bit((cc->cc_data_msb << 7) |
+					     cc->cc_data_lsb);
+	cc->cc_data_msb = cc->cc_data_lsb = 0;
+}
+
+/* convert CC event to MIDI 2.0 UMP */
+static int cc_ev_to_ump_midi2(const struct snd_seq_event *event,
+			      struct snd_seq_client_port *dest_port,
+			      union snd_ump_midi2_msg *data,
+			      unsigned char status)
+{
+	unsigned char channel = event->data.control.channel & 0x0f;
+	unsigned char index = event->data.control.param & 0x7f;
+	unsigned char val = event->data.control.value & 0x7f;
+	struct snd_seq_ump_midi2_bank *cc = &dest_port->midi2_bank[channel];
+
+	/* process special CC's (bank/rpn/nrpn) */
+	switch (index) {
+	case UMP_CC_RPN_MSB:
+		cc->rpn_set = 1;
+		cc->cc_rpn_msb = val;
+		return 0; // skip
+	case UMP_CC_RPN_LSB:
+		cc->rpn_set = 1;
+		cc->cc_rpn_lsb = val;
+		return 0; // skip
+	case UMP_CC_NRPN_MSB:
+		cc->nrpn_set = 1;
+		cc->cc_nrpn_msb = val;
+		return 0; // skip
+	case UMP_CC_NRPN_LSB:
+		cc->nrpn_set = 1;
+		cc->cc_nrpn_lsb = val;
+		return 0; // skip
+	case UMP_CC_DATA:
+		cc->cc_data_msb = val;
+		return 0; // skip
+	case UMP_CC_BANK_SELECT:
+		cc->bank_set = 1;
+		cc->cc_bank_msb = val;
+		return 0; // skip
+	case UMP_CC_BANK_SELECT_LSB:
+		cc->bank_set = 1;
+		cc->cc_bank_lsb = val;
+		return 0; // skip
+	case UMP_CC_DATA_LSB:
+		cc->cc_data_lsb = val;
+		if (!(cc->rpn_set || cc->nrpn_set))
+			return 0; // skip
+		fill_rpn(cc, data);
+		return 1;
+	}
+
+	data->cc.status = status;
+	data->cc.channel = channel;
+	data->cc.index = index;
+	data->cc.data = upscale_7_to_32bit(event->data.control.value & 0x7f);
+	return 1;
+}
+
+/* convert one-parameter control event to MIDI 2.0 UMP */
+static int ctrl_ev_to_ump_midi2(const struct snd_seq_event *event,
+				struct snd_seq_client_port *dest_port,
+				union snd_ump_midi2_msg *data,
+				unsigned char status)
+{
+	data->caf.status = status;
+	data->caf.channel = event->data.control.channel & 0x0f;
+	data->caf.data = upscale_7_to_32bit(event->data.control.value & 0x7f);
+	return 1;
+}
+
+/* convert program change event to MIDI 2.0 UMP */
+static int pgm_ev_to_ump_midi2(const struct snd_seq_event *event,
+			       struct snd_seq_client_port *dest_port,
+			       union snd_ump_midi2_msg *data,
+			       unsigned char status)
+{
+	unsigned char channel = event->data.control.channel & 0x0f;
+	struct snd_seq_ump_midi2_bank *cc = &dest_port->midi2_bank[channel];
+
+	data->pg.status = status;
+	data->pg.channel = channel;
+	data->pg.program = event->data.control.value & 0x7f;
+	if (cc->bank_set) {
+		data->pg.bank_valid = 1;
+		data->pg.bank_msb = cc->cc_bank_msb;
+		data->pg.bank_lsb = cc->cc_bank_lsb;
+		cc->bank_set = 0;
+		cc->cc_bank_msb = cc->cc_bank_lsb = 0;
+	}
+	return 1;
+}
+
+/* convert pitchbend event to MIDI 2.0 UMP */
+static int pitchbend_ev_to_ump_midi2(const struct snd_seq_event *event,
+				     struct snd_seq_client_port *dest_port,
+				     union snd_ump_midi2_msg *data,
+				     unsigned char status)
+{
+	int val = event->data.control.value + 8192;
+
+	val = clamp(val, 0, 0x3fff);
+	data->pb.status = status;
+	data->pb.channel = event->data.control.channel & 0x0f;
+	data->pb.data = upscale_14_to_32bit(val);
+	return 1;
+}
+
+/* convert 14bit control event to MIDI 2.0 UMP; split to two events */
+static int ctrl14_ev_to_ump_midi2(const struct snd_seq_event *event,
+				  struct snd_seq_client_port *dest_port,
+				  union snd_ump_midi2_msg *data,
+				  unsigned char status)
+{
+	unsigned char channel = event->data.control.channel & 0x0f;
+	unsigned char index = event->data.control.param & 0x7f;
+	struct snd_seq_ump_midi2_bank *cc = &dest_port->midi2_bank[channel];
+	unsigned char msb, lsb;
+
+	msb = (event->data.control.value >> 7) & 0x7f;
+	lsb = event->data.control.value & 0x7f;
+	/* process special CC's (bank/rpn/nrpn) */
+	switch (index) {
+	case UMP_CC_BANK_SELECT:
+		cc->cc_bank_msb = msb;
+		fallthrough;
+	case UMP_CC_BANK_SELECT_LSB:
+		cc->bank_set = 1;
+		cc->cc_bank_lsb = lsb;
+		return 0; // skip
+	case UMP_CC_RPN_MSB:
+		cc->cc_rpn_msb = msb;
+		fallthrough;
+	case UMP_CC_RPN_LSB:
+		cc->rpn_set = 1;
+		cc->cc_rpn_lsb = lsb;
+		return 0; // skip
+	case UMP_CC_NRPN_MSB:
+		cc->cc_nrpn_msb = msb;
+		fallthrough;
+	case UMP_CC_NRPN_LSB:
+		cc->nrpn_set = 1;
+		cc->cc_nrpn_lsb = lsb;
+		return 0; // skip
+	case UMP_CC_DATA:
+		cc->cc_data_msb = msb;
+		fallthrough;
+	case UMP_CC_DATA_LSB:
+		cc->cc_data_lsb = lsb;
+		if (!(cc->rpn_set || cc->nrpn_set))
+			return 0; // skip
+		fill_rpn(cc, data);
+		return 1;
+	}
+
+	data->cc.status = UMP_MSG_STATUS_CC;
+	data->cc.channel = channel;
+	data->cc.index = index;
+	if (event->data.control.param < 0x20) {
+		data->cc.data = upscale_7_to_32bit(msb);
+		data[1] = data[0];
+		data[1].cc.index = event->data.control.param | 0x20;
+		data[1].cc.data = upscale_7_to_32bit(lsb);
+		return 2;
+	}
+
+	data->cc.data = upscale_7_to_32bit(lsb);
+	return 1;
+}
+
+/* convert RPN/NRPN event to MIDI 2.0 UMP */
+static int rpn_ev_to_ump_midi2(const struct snd_seq_event *event,
+			       struct snd_seq_client_port *dest_port,
+			       union snd_ump_midi2_msg *data,
+			       unsigned char status)
+{
+	data->rpn.status = status;
+	data->rpn.channel = event->data.control.channel;
+	data->rpn.bank = (event->data.control.param >> 7) & 0x7f;
+	data->rpn.index = event->data.control.param & 0x7f;
+	data->rpn.data = upscale_14_to_32bit(event->data.control.value & 0x3fff);
+	return 1;
+}
+
+/* convert system / RT message to UMP */
+static int system_ev_to_ump_midi2(const struct snd_seq_event *event,
+				  struct snd_seq_client_port *dest_port,
+				  union snd_ump_midi2_msg *data,
+				  unsigned char status)
+{
+	return system_ev_to_ump_midi1(event, dest_port,
+				      (union snd_ump_midi1_msg *)data,
+				      status);
+}
+
+/* convert system / RT message with 1 parameter to UMP */
+static int system_1p_ev_to_ump_midi2(const struct snd_seq_event *event,
+				     struct snd_seq_client_port *dest_port,
+				     union snd_ump_midi2_msg *data,
+				     unsigned char status)
+{
+	return system_1p_ev_to_ump_midi1(event, dest_port,
+					 (union snd_ump_midi1_msg *)data,
+					 status);
+}
+
+/* convert system / RT message with two parameters to UMP */
+static int system_2p_ev_to_ump_midi2(const struct snd_seq_event *event,
+				     struct snd_seq_client_port *dest_port,
+				     union snd_ump_midi2_msg *data,
+				     unsigned char status)
+{
+	return system_1p_ev_to_ump_midi1(event, dest_port,
+					 (union snd_ump_midi1_msg *)data,
+					 status);
+}
+
+struct seq_ev_to_ump {
+	int seq_type;
+	unsigned char status;
+	int (*midi1_encode)(const struct snd_seq_event *event,
+			    struct snd_seq_client_port *dest_port,
+			    union snd_ump_midi1_msg *data,
+			    unsigned char status);
+	int (*midi2_encode)(const struct snd_seq_event *event,
+			    struct snd_seq_client_port *dest_port,
+			    union snd_ump_midi2_msg *data,
+			    unsigned char status);
+};
+
+static const struct seq_ev_to_ump seq_ev_ump_encoders[] = {
+	{ SNDRV_SEQ_EVENT_NOTEON, UMP_MSG_STATUS_NOTE_ON,
+	  note_ev_to_ump_midi1, note_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_NOTEOFF, UMP_MSG_STATUS_NOTE_OFF,
+	  note_ev_to_ump_midi1, note_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_KEYPRESS, UMP_MSG_STATUS_POLY_PRESSURE,
+	  note_ev_to_ump_midi1, paf_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_CONTROLLER, UMP_MSG_STATUS_CC,
+	  cc_ev_to_ump_midi1, cc_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_PGMCHANGE, UMP_MSG_STATUS_PROGRAM,
+	  ctrl_ev_to_ump_midi1, pgm_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_CHANPRESS, UMP_MSG_STATUS_CHANNEL_PRESSURE,
+	  ctrl_ev_to_ump_midi1, ctrl_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_PITCHBEND, UMP_MSG_STATUS_PITCH_BEND,
+	  pitchbend_ev_to_ump_midi1, pitchbend_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_CONTROL14, 0,
+	  ctrl14_ev_to_ump_midi1, ctrl14_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_NONREGPARAM, UMP_MSG_STATUS_NRPN,
+	  rpn_ev_to_ump_midi1, rpn_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_REGPARAM, UMP_MSG_STATUS_RPN,
+	  rpn_ev_to_ump_midi1, rpn_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_QFRAME, UMP_SYSTEM_STATUS_MIDI_TIME_CODE,
+	  system_1p_ev_to_ump_midi1, system_1p_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_SONGPOS, UMP_SYSTEM_STATUS_SONG_POSITION,
+	  system_2p_ev_to_ump_midi1, system_2p_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_SONGSEL, UMP_SYSTEM_STATUS_SONG_SELECT,
+	  system_1p_ev_to_ump_midi1, system_1p_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_TUNE_REQUEST, UMP_SYSTEM_STATUS_TUNE_REQUEST,
+	  system_ev_to_ump_midi1, system_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_CLOCK, UMP_SYSTEM_STATUS_TIMING_CLOCK,
+	  system_ev_to_ump_midi1, system_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_START, UMP_SYSTEM_STATUS_START,
+	  system_ev_to_ump_midi1, system_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_CONTINUE, UMP_SYSTEM_STATUS_CONTINUE,
+	  system_ev_to_ump_midi1, system_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_STOP, UMP_SYSTEM_STATUS_STOP,
+	  system_ev_to_ump_midi1, system_ev_to_ump_midi2 },
+	{ SNDRV_SEQ_EVENT_SENSING, UMP_SYSTEM_STATUS_ACTIVE_SENSING,
+	  system_ev_to_ump_midi1, system_ev_to_ump_midi2 },
+};
+
+static const struct seq_ev_to_ump *find_ump_encoder(int type)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(seq_ev_ump_encoders); i++)
+		if (seq_ev_ump_encoders[i].seq_type == type)
+			return &seq_ev_ump_encoders[i];
+
+	return NULL;
+}
+
+static void setup_ump_event(struct snd_seq_ump_event *dest,
+			    const struct snd_seq_event *src)
+{
+	memcpy(dest, src, sizeof(*src));
+	dest->type = 0;
+	dest->flags |= SNDRV_SEQ_EVENT_UMP;
+	dest->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+	memset(dest->ump, 0, sizeof(dest->ump));
+}
+
+/* Convert ALSA seq event to UMP MIDI 1.0 and deliver it */
+static int cvt_to_ump_midi1(struct snd_seq_client *dest,
+			    struct snd_seq_client_port *dest_port,
+			    struct snd_seq_event *event,
+			    int atomic, int hop)
+{
+	const struct seq_ev_to_ump *encoder;
+	struct snd_seq_ump_event ev_cvt;
+	union snd_ump_midi1_msg data[4];
+	int i, n, err;
+
+	encoder = find_ump_encoder(event->type);
+	if (!encoder)
+		return __snd_seq_deliver_single_event(dest, dest_port,
+						      event, atomic, hop);
+
+	data->raw = make_raw_ump(dest_port, UMP_MSG_TYPE_MIDI1_CHANNEL_VOICE);
+	n = encoder->midi1_encode(event, dest_port, data, encoder->status);
+	if (!n)
+		return 0;
+
+	setup_ump_event(&ev_cvt, event);
+	for (i = 0; i < n; i++) {
+		ev_cvt.ump[0] = data[i].raw;
+		err = __snd_seq_deliver_single_event(dest, dest_port,
+						     (struct snd_seq_event *)&ev_cvt,
+						     atomic, hop);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* Convert ALSA seq event to UMP MIDI 2.0 and deliver it */
+static int cvt_to_ump_midi2(struct snd_seq_client *dest,
+			    struct snd_seq_client_port *dest_port,
+			    struct snd_seq_event *event,
+			    int atomic, int hop)
+{
+	const struct seq_ev_to_ump *encoder;
+	struct snd_seq_ump_event ev_cvt;
+	union snd_ump_midi2_msg data[2];
+	int i, n, err;
+
+	encoder = find_ump_encoder(event->type);
+	if (!encoder)
+		return __snd_seq_deliver_single_event(dest, dest_port,
+						      event, atomic, hop);
+
+	data->raw[0] = make_raw_ump(dest_port, UMP_MSG_TYPE_MIDI2_CHANNEL_VOICE);
+	data->raw[1] = 0;
+	n = encoder->midi2_encode(event, dest_port, data, encoder->status);
+	if (!n)
+		return 0;
+
+	setup_ump_event(&ev_cvt, event);
+	for (i = 0; i < n; i++) {
+		memcpy(ev_cvt.ump, &data[i], sizeof(data[i]));
+		err = __snd_seq_deliver_single_event(dest, dest_port,
+						     (struct snd_seq_event *)&ev_cvt,
+						     atomic, hop);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* Fill up a sysex7 UMP from the byte stream */
+static void fill_sysex7_ump(struct snd_seq_client_port *dest_port,
+			    u32 *val, u8 status, u8 *buf, int len)
+{
+	memset(val, 0, 8);
+	memcpy((u8 *)val + 2, buf, len);
+#ifdef __LITTLE_ENDIAN
+	swab32_array(val, 2);
+#endif
+	val[0] |= ump_compose(UMP_MSG_TYPE_DATA, get_ump_group(dest_port),
+			      status, len);
+}
+
+/* Convert sysex var event to UMP sysex7 packets and deliver them */
+static int cvt_sysex_to_ump(struct snd_seq_client *dest,
+			    struct snd_seq_client_port *dest_port,
+			    struct snd_seq_event *event,
+			    int atomic, int hop)
+{
+	struct snd_seq_ump_event ev_cvt;
+	unsigned char status;
+	u8 buf[6], *xbuf;
+	int offset = 0;
+	int len, err;
+
+	if (!snd_seq_ev_is_variable(event))
+		return 0;
+
+	setup_ump_event(&ev_cvt, event);
+	for (;;) {
+		len = snd_seq_expand_var_event_at(event, sizeof(buf), buf, offset);
+		if (len <= 0)
+			break;
+		if (WARN_ON(len > 6))
+			break;
+		offset += len;
+		xbuf = buf;
+		if (*xbuf == UMP_MIDI1_MSG_SYSEX_START) {
+			status = UMP_SYSEX_STATUS_START;
+			xbuf++;
+			len--;
+			if (len > 0 && xbuf[len - 1] == UMP_MIDI1_MSG_SYSEX_END) {
+				status = UMP_SYSEX_STATUS_SINGLE;
+				len--;
+			}
+		} else {
+			if (xbuf[len - 1] == UMP_MIDI1_MSG_SYSEX_END) {
+				status = UMP_SYSEX_STATUS_END;
+				len--;
+			} else {
+				status = UMP_SYSEX_STATUS_CONTINUE;
+			}
+		}
+		fill_sysex7_ump(dest_port, ev_cvt.ump, status, xbuf, len);
+		err = __snd_seq_deliver_single_event(dest, dest_port,
+						     (struct snd_seq_event *)&ev_cvt,
+						     atomic, hop);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/* Convert to UMP packet and deliver */
+int snd_seq_deliver_to_ump(struct snd_seq_client *source,
+			   struct snd_seq_client *dest,
+			   struct snd_seq_client_port *dest_port,
+			   struct snd_seq_event *event,
+			   int atomic, int hop)
+{
+	if (dest->group_filter & (1U << dest_port->ump_group))
+		return 0; /* group filtered - skip the event */
+	if (event->type == SNDRV_SEQ_EVENT_SYSEX)
+		return cvt_sysex_to_ump(dest, dest_port, event, atomic, hop);
+	else if (snd_seq_client_is_midi2(dest))
+		return cvt_to_ump_midi2(dest, dest_port, event, atomic, hop);
+	else
+		return cvt_to_ump_midi1(dest, dest_port, event, atomic, hop);
+}
diff --git a/sound/core/seq/seq_ump_convert.h b/sound/core/seq/seq_ump_convert.h
new file mode 100644
index 0000000000..6c146d8032
--- /dev/null
+++ b/sound/core/seq/seq_ump_convert.h
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ALSA sequencer event conversion between UMP and legacy clients
+ */
+#ifndef __SEQ_UMP_CONVERT_H
+#define __SEQ_UMP_CONVERT_H
+
+#include "seq_clientmgr.h"
+#include "seq_ports.h"
+
+int snd_seq_deliver_from_ump(struct snd_seq_client *source,
+			     struct snd_seq_client *dest,
+			     struct snd_seq_client_port *dest_port,
+			     struct snd_seq_event *event,
+			     int atomic, int hop);
+int snd_seq_deliver_to_ump(struct snd_seq_client *source,
+			   struct snd_seq_client *dest,
+			   struct snd_seq_client_port *dest_port,
+			   struct snd_seq_event *event,
+			   int atomic, int hop);
+
+#endif /* __SEQ_UMP_CONVERT_H */
diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c
new file mode 100644
index 0000000000..1b9260108e
--- /dev/null
+++ b/sound/core/seq/seq_virmidi.c
@@ -0,0 +1,528 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Virtual Raw MIDI client on Sequencer
+ *
+ *  Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>,
+ *                        Jaroslav Kysela <perex@perex.cz>
+ */
+
+/*
+ * Virtual Raw MIDI client
+ *
+ * The virtual rawmidi client is a sequencer client which associate
+ * a rawmidi device file.  The created rawmidi device file can be
+ * accessed as a normal raw midi, but its MIDI source and destination
+ * are arbitrary.  For example, a user-client software synth connected
+ * to this port can be used as a normal midi device as well.
+ *
+ * The virtual rawmidi device accepts also multiple opens.  Each file
+ * has its own input buffer, so that no conflict would occur.  The drain
+ * of input/output buffer acts only to the local buffer.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/rawmidi.h>
+#include <sound/info.h>
+#include <sound/control.h>
+#include <sound/minors.h>
+#include <sound/seq_kernel.h>
+#include <sound/seq_midi_event.h>
+#include <sound/seq_virmidi.h>
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("Virtual Raw MIDI client on Sequencer");
+MODULE_LICENSE("GPL");
+
+/*
+ * initialize an event record
+ */
+static void snd_virmidi_init_event(struct snd_virmidi *vmidi,
+				   struct snd_seq_event *ev)
+{
+	memset(ev, 0, sizeof(*ev));
+	ev->source.port = vmidi->port;
+	switch (vmidi->seq_mode) {
+	case SNDRV_VIRMIDI_SEQ_DISPATCH:
+		ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+		break;
+	case SNDRV_VIRMIDI_SEQ_ATTACH:
+		/* FIXME: source and destination are same - not good.. */
+		ev->dest.client = vmidi->client;
+		ev->dest.port = vmidi->port;
+		break;
+	}
+	ev->type = SNDRV_SEQ_EVENT_NONE;
+}
+
+/*
+ * decode input event and put to read buffer of each opened file
+ */
+static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev,
+					 struct snd_seq_event *ev,
+					 bool atomic)
+{
+	struct snd_virmidi *vmidi;
+	unsigned char msg[4];
+	int len;
+
+	if (atomic)
+		read_lock(&rdev->filelist_lock);
+	else
+		down_read(&rdev->filelist_sem);
+	list_for_each_entry(vmidi, &rdev->filelist, list) {
+		if (!READ_ONCE(vmidi->trigger))
+			continue;
+		if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
+			if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
+				continue;
+			snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
+			snd_midi_event_reset_decode(vmidi->parser);
+		} else {
+			len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
+			if (len > 0)
+				snd_rawmidi_receive(vmidi->substream, msg, len);
+		}
+	}
+	if (atomic)
+		read_unlock(&rdev->filelist_lock);
+	else
+		up_read(&rdev->filelist_sem);
+
+	return 0;
+}
+
+/*
+ * event handler of virmidi port
+ */
+static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
+				   void *private_data, int atomic, int hop)
+{
+	struct snd_virmidi_dev *rdev;
+
+	rdev = private_data;
+	if (!(rdev->flags & SNDRV_VIRMIDI_USE))
+		return 0; /* ignored */
+	return snd_virmidi_dev_receive_event(rdev, ev, atomic);
+}
+
+/*
+ * trigger rawmidi stream for input
+ */
+static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	struct snd_virmidi *vmidi = substream->runtime->private_data;
+
+	WRITE_ONCE(vmidi->trigger, !!up);
+}
+
+/* process rawmidi bytes and send events;
+ * we need no lock here for vmidi->event since it's handled only in this work
+ */
+static void snd_vmidi_output_work(struct work_struct *work)
+{
+	struct snd_virmidi *vmidi;
+	struct snd_rawmidi_substream *substream;
+	unsigned char input;
+	int ret;
+
+	vmidi = container_of(work, struct snd_virmidi, output_work);
+	substream = vmidi->substream;
+
+	/* discard the outputs in dispatch mode unless subscribed */
+	if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
+	    !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
+		snd_rawmidi_proceed(substream);
+		return;
+	}
+
+	while (READ_ONCE(vmidi->trigger)) {
+		if (snd_rawmidi_transmit(substream, &input, 1) != 1)
+			break;
+		if (!snd_midi_event_encode_byte(vmidi->parser, input,
+						&vmidi->event))
+			continue;
+		if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
+			ret = snd_seq_kernel_client_dispatch(vmidi->client,
+							     &vmidi->event,
+							     false, 0);
+			vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
+			if (ret < 0)
+				break;
+		}
+		/* rawmidi input might be huge, allow to have a break */
+		cond_resched();
+	}
+}
+
+/*
+ * trigger rawmidi stream for output
+ */
+static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	struct snd_virmidi *vmidi = substream->runtime->private_data;
+
+	WRITE_ONCE(vmidi->trigger, !!up);
+	if (up)
+		queue_work(system_highpri_wq, &vmidi->output_work);
+}
+
+/*
+ * open rawmidi handle for input
+ */
+static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	struct snd_virmidi *vmidi;
+
+	vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
+	if (vmidi == NULL)
+		return -ENOMEM;
+	vmidi->substream = substream;
+	if (snd_midi_event_new(0, &vmidi->parser) < 0) {
+		kfree(vmidi);
+		return -ENOMEM;
+	}
+	vmidi->seq_mode = rdev->seq_mode;
+	vmidi->client = rdev->client;
+	vmidi->port = rdev->port;	
+	runtime->private_data = vmidi;
+	down_write(&rdev->filelist_sem);
+	write_lock_irq(&rdev->filelist_lock);
+	list_add_tail(&vmidi->list, &rdev->filelist);
+	write_unlock_irq(&rdev->filelist_lock);
+	up_write(&rdev->filelist_sem);
+	vmidi->rdev = rdev;
+	return 0;
+}
+
+/*
+ * open rawmidi handle for output
+ */
+static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
+	struct snd_rawmidi_runtime *runtime = substream->runtime;
+	struct snd_virmidi *vmidi;
+
+	vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
+	if (vmidi == NULL)
+		return -ENOMEM;
+	vmidi->substream = substream;
+	if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
+		kfree(vmidi);
+		return -ENOMEM;
+	}
+	vmidi->seq_mode = rdev->seq_mode;
+	vmidi->client = rdev->client;
+	vmidi->port = rdev->port;
+	snd_virmidi_init_event(vmidi, &vmidi->event);
+	vmidi->rdev = rdev;
+	INIT_WORK(&vmidi->output_work, snd_vmidi_output_work);
+	runtime->private_data = vmidi;
+	return 0;
+}
+
+/*
+ * close rawmidi handle for input
+ */
+static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
+	struct snd_virmidi *vmidi = substream->runtime->private_data;
+
+	down_write(&rdev->filelist_sem);
+	write_lock_irq(&rdev->filelist_lock);
+	list_del(&vmidi->list);
+	write_unlock_irq(&rdev->filelist_lock);
+	up_write(&rdev->filelist_sem);
+	snd_midi_event_free(vmidi->parser);
+	substream->runtime->private_data = NULL;
+	kfree(vmidi);
+	return 0;
+}
+
+/*
+ * close rawmidi handle for output
+ */
+static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_virmidi *vmidi = substream->runtime->private_data;
+
+	WRITE_ONCE(vmidi->trigger, false); /* to be sure */
+	cancel_work_sync(&vmidi->output_work);
+	snd_midi_event_free(vmidi->parser);
+	substream->runtime->private_data = NULL;
+	kfree(vmidi);
+	return 0;
+}
+
+/*
+ * drain output work queue
+ */
+static void snd_virmidi_output_drain(struct snd_rawmidi_substream *substream)
+{
+	struct snd_virmidi *vmidi = substream->runtime->private_data;
+
+	flush_work(&vmidi->output_work);
+}
+
+/*
+ * subscribe callback - allow output to rawmidi device
+ */
+static int snd_virmidi_subscribe(void *private_data,
+				 struct snd_seq_port_subscribe *info)
+{
+	struct snd_virmidi_dev *rdev;
+
+	rdev = private_data;
+	if (!try_module_get(rdev->card->module))
+		return -EFAULT;
+	rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
+	return 0;
+}
+
+/*
+ * unsubscribe callback - disallow output to rawmidi device
+ */
+static int snd_virmidi_unsubscribe(void *private_data,
+				   struct snd_seq_port_subscribe *info)
+{
+	struct snd_virmidi_dev *rdev;
+
+	rdev = private_data;
+	rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
+	module_put(rdev->card->module);
+	return 0;
+}
+
+
+/*
+ * use callback - allow input to rawmidi device
+ */
+static int snd_virmidi_use(void *private_data,
+			   struct snd_seq_port_subscribe *info)
+{
+	struct snd_virmidi_dev *rdev;
+
+	rdev = private_data;
+	if (!try_module_get(rdev->card->module))
+		return -EFAULT;
+	rdev->flags |= SNDRV_VIRMIDI_USE;
+	return 0;
+}
+
+/*
+ * unuse callback - disallow input to rawmidi device
+ */
+static int snd_virmidi_unuse(void *private_data,
+			     struct snd_seq_port_subscribe *info)
+{
+	struct snd_virmidi_dev *rdev;
+
+	rdev = private_data;
+	rdev->flags &= ~SNDRV_VIRMIDI_USE;
+	module_put(rdev->card->module);
+	return 0;
+}
+
+
+/*
+ *  Register functions
+ */
+
+static const struct snd_rawmidi_ops snd_virmidi_input_ops = {
+	.open = snd_virmidi_input_open,
+	.close = snd_virmidi_input_close,
+	.trigger = snd_virmidi_input_trigger,
+};
+
+static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
+	.open = snd_virmidi_output_open,
+	.close = snd_virmidi_output_close,
+	.trigger = snd_virmidi_output_trigger,
+	.drain = snd_virmidi_output_drain,
+};
+
+/*
+ * create a sequencer client and a port
+ */
+static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
+{
+	int client;
+	struct snd_seq_port_callback pcallbacks;
+	struct snd_seq_port_info *pinfo;
+	int err;
+
+	if (rdev->client >= 0)
+		return 0;
+
+	pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo) {
+		err = -ENOMEM;
+		goto __error;
+	}
+
+	client = snd_seq_create_kernel_client(rdev->card, rdev->device,
+					      "%s %d-%d", rdev->rmidi->name,
+					      rdev->card->number,
+					      rdev->device);
+	if (client < 0) {
+		err = client;
+		goto __error;
+	}
+	rdev->client = client;
+
+	/* create a port */
+	pinfo->addr.client = client;
+	sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
+	/* set all capabilities */
+	pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+	pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
+	pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+	pinfo->direction = SNDRV_SEQ_PORT_DIR_BIDIRECTION;
+	pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
+		| SNDRV_SEQ_PORT_TYPE_SOFTWARE
+		| SNDRV_SEQ_PORT_TYPE_PORT;
+	pinfo->midi_channels = 16;
+	memset(&pcallbacks, 0, sizeof(pcallbacks));
+	pcallbacks.owner = THIS_MODULE;
+	pcallbacks.private_data = rdev;
+	pcallbacks.subscribe = snd_virmidi_subscribe;
+	pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
+	pcallbacks.use = snd_virmidi_use;
+	pcallbacks.unuse = snd_virmidi_unuse;
+	pcallbacks.event_input = snd_virmidi_event_input;
+	pinfo->kernel = &pcallbacks;
+	err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
+	if (err < 0) {
+		snd_seq_delete_kernel_client(client);
+		rdev->client = -1;
+		goto __error;
+	}
+
+	rdev->port = pinfo->addr.port;
+	err = 0; /* success */
+
+ __error:
+	kfree(pinfo);
+	return err;
+}
+
+
+/*
+ * release the sequencer client
+ */
+static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
+{
+	if (rdev->client >= 0) {
+		snd_seq_delete_kernel_client(rdev->client);
+		rdev->client = -1;
+	}
+}
+
+/*
+ * register the device
+ */
+static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
+{
+	struct snd_virmidi_dev *rdev = rmidi->private_data;
+	int err;
+
+	switch (rdev->seq_mode) {
+	case SNDRV_VIRMIDI_SEQ_DISPATCH:
+		err = snd_virmidi_dev_attach_seq(rdev);
+		if (err < 0)
+			return err;
+		break;
+	case SNDRV_VIRMIDI_SEQ_ATTACH:
+		if (rdev->client == 0)
+			return -EINVAL;
+		/* should check presence of port more strictly.. */
+		break;
+	default:
+		pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+
+/*
+ * unregister the device
+ */
+static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
+{
+	struct snd_virmidi_dev *rdev = rmidi->private_data;
+
+	if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
+		snd_virmidi_dev_detach_seq(rdev);
+	return 0;
+}
+
+/*
+ *
+ */
+static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
+	.dev_register = snd_virmidi_dev_register,
+	.dev_unregister = snd_virmidi_dev_unregister,
+};
+
+/*
+ * free device
+ */
+static void snd_virmidi_free(struct snd_rawmidi *rmidi)
+{
+	struct snd_virmidi_dev *rdev = rmidi->private_data;
+	kfree(rdev);
+}
+
+/*
+ * create a new device
+ *
+ */
+/* exported */
+int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
+{
+	struct snd_rawmidi *rmidi;
+	struct snd_virmidi_dev *rdev;
+	int err;
+	
+	*rrmidi = NULL;
+	err = snd_rawmidi_new(card, "VirMidi", device,
+			      16,	/* may be configurable */
+			      16,	/* may be configurable */
+			      &rmidi);
+	if (err < 0)
+		return err;
+	strcpy(rmidi->name, rmidi->id);
+	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+	if (rdev == NULL) {
+		snd_device_free(card, rmidi);
+		return -ENOMEM;
+	}
+	rdev->card = card;
+	rdev->rmidi = rmidi;
+	rdev->device = device;
+	rdev->client = -1;
+	init_rwsem(&rdev->filelist_sem);
+	rwlock_init(&rdev->filelist_lock);
+	INIT_LIST_HEAD(&rdev->filelist);
+	rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
+	rmidi->private_data = rdev;
+	rmidi->private_free = snd_virmidi_free;
+	rmidi->ops = &snd_virmidi_global_ops;
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
+	rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
+			    SNDRV_RAWMIDI_INFO_OUTPUT |
+			    SNDRV_RAWMIDI_INFO_DUPLEX;
+	*rrmidi = rmidi;
+	return 0;
+}
+EXPORT_SYMBOL(snd_virmidi_new);
diff --git a/sound/core/seq_device.c b/sound/core/seq_device.c
new file mode 100644
index 0000000000..7f3fd8eb01
--- /dev/null
+++ b/sound/core/seq_device.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  ALSA sequencer device management
+ *  Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
+ *
+ *----------------------------------------------------------------
+ *
+ * This device handler separates the card driver module from sequencer
+ * stuff (sequencer core, synth drivers, etc), so that user can avoid
+ * to spend unnecessary resources e.g. if he needs only listening to
+ * MP3s.
+ *
+ * The card (or lowlevel) driver creates a sequencer device entry
+ * via snd_seq_device_new().  This is an entry pointer to communicate
+ * with the sequencer device "driver", which is involved with the
+ * actual part to communicate with the sequencer core.
+ * Each sequencer device entry has an id string and the corresponding
+ * driver with the same id is loaded when required.  For example,
+ * lowlevel codes to access emu8000 chip on sbawe card are included in
+ * emu8000-synth module.  To activate this module, the hardware
+ * resources like i/o port are passed via snd_seq_device argument.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/seq_device.h>
+#include <sound/seq_kernel.h>
+#include <sound/initval.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA sequencer device management");
+MODULE_LICENSE("GPL");
+
+/*
+ * bus definition
+ */
+static int snd_seq_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct snd_seq_device *sdev = to_seq_dev(dev);
+	struct snd_seq_driver *sdrv = to_seq_drv(drv);
+
+	return strcmp(sdrv->id, sdev->id) == 0 &&
+		sdrv->argsize == sdev->argsize;
+}
+
+static struct bus_type snd_seq_bus_type = {
+	.name = "snd_seq",
+	.match = snd_seq_bus_match,
+};
+
+/*
+ * proc interface -- just for compatibility
+ */
+#ifdef CONFIG_SND_PROC_FS
+static struct snd_info_entry *info_entry;
+
+static int print_dev_info(struct device *dev, void *data)
+{
+	struct snd_seq_device *sdev = to_seq_dev(dev);
+	struct snd_info_buffer *buffer = data;
+
+	snd_iprintf(buffer, "snd-%s,%s,%d\n", sdev->id,
+		    dev->driver ? "loaded" : "empty",
+		    dev->driver ? 1 : 0);
+	return 0;
+}
+
+static void snd_seq_device_info(struct snd_info_entry *entry,
+				struct snd_info_buffer *buffer)
+{
+	bus_for_each_dev(&snd_seq_bus_type, NULL, buffer, print_dev_info);
+}
+#endif
+
+/*
+ * load all registered drivers (called from seq_clientmgr.c)
+ */
+
+#ifdef CONFIG_MODULES
+/* flag to block auto-loading */
+static atomic_t snd_seq_in_init = ATOMIC_INIT(1); /* blocked as default */
+
+static int request_seq_drv(struct device *dev, void *data)
+{
+	struct snd_seq_device *sdev = to_seq_dev(dev);
+
+	if (!dev->driver)
+		request_module("snd-%s", sdev->id);
+	return 0;
+}
+
+static void autoload_drivers(struct work_struct *work)
+{
+	/* avoid reentrance */
+	if (atomic_inc_return(&snd_seq_in_init) == 1)
+		bus_for_each_dev(&snd_seq_bus_type, NULL, NULL,
+				 request_seq_drv);
+	atomic_dec(&snd_seq_in_init);
+}
+
+static DECLARE_WORK(autoload_work, autoload_drivers);
+
+static void queue_autoload_drivers(void)
+{
+	schedule_work(&autoload_work);
+}
+
+void snd_seq_autoload_init(void)
+{
+	atomic_dec(&snd_seq_in_init);
+#ifdef CONFIG_SND_SEQUENCER_MODULE
+	/* initial autoload only when snd-seq is a module */
+	queue_autoload_drivers();
+#endif
+}
+EXPORT_SYMBOL(snd_seq_autoload_init);
+
+void snd_seq_autoload_exit(void)
+{
+	atomic_inc(&snd_seq_in_init);
+}
+EXPORT_SYMBOL(snd_seq_autoload_exit);
+
+void snd_seq_device_load_drivers(void)
+{
+	queue_autoload_drivers();
+	flush_work(&autoload_work);
+}
+EXPORT_SYMBOL(snd_seq_device_load_drivers);
+
+static inline void cancel_autoload_drivers(void)
+{
+	cancel_work_sync(&autoload_work);
+}
+#else
+static inline void queue_autoload_drivers(void)
+{
+}
+
+static inline void cancel_autoload_drivers(void)
+{
+}
+#endif
+
+/*
+ * device management
+ */
+static int snd_seq_device_dev_free(struct snd_device *device)
+{
+	struct snd_seq_device *dev = device->device_data;
+
+	cancel_autoload_drivers();
+	if (dev->private_free)
+		dev->private_free(dev);
+	put_device(&dev->dev);
+	return 0;
+}
+
+static int snd_seq_device_dev_register(struct snd_device *device)
+{
+	struct snd_seq_device *dev = device->device_data;
+	int err;
+
+	err = device_add(&dev->dev);
+	if (err < 0)
+		return err;
+	if (!dev->dev.driver)
+		queue_autoload_drivers();
+	return 0;
+}
+
+static int snd_seq_device_dev_disconnect(struct snd_device *device)
+{
+	struct snd_seq_device *dev = device->device_data;
+
+	device_del(&dev->dev);
+	return 0;
+}
+
+static void snd_seq_dev_release(struct device *dev)
+{
+	kfree(to_seq_dev(dev));
+}
+
+/*
+ * register a sequencer device
+ * card = card info
+ * device = device number (if any)
+ * id = id of driver
+ * result = return pointer (NULL allowed if unnecessary)
+ */
+int snd_seq_device_new(struct snd_card *card, int device, const char *id,
+		       int argsize, struct snd_seq_device **result)
+{
+	struct snd_seq_device *dev;
+	int err;
+	static const struct snd_device_ops dops = {
+		.dev_free = snd_seq_device_dev_free,
+		.dev_register = snd_seq_device_dev_register,
+		.dev_disconnect = snd_seq_device_dev_disconnect,
+	};
+
+	if (result)
+		*result = NULL;
+
+	if (snd_BUG_ON(!id))
+		return -EINVAL;
+
+	dev = kzalloc(sizeof(*dev) + argsize, GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	/* set up device info */
+	dev->card = card;
+	dev->device = device;
+	dev->id = id;
+	dev->argsize = argsize;
+
+	device_initialize(&dev->dev);
+	dev->dev.parent = &card->card_dev;
+	dev->dev.bus = &snd_seq_bus_type;
+	dev->dev.release = snd_seq_dev_release;
+	dev_set_name(&dev->dev, "%s-%d-%d", dev->id, card->number, device);
+
+	/* add this device to the list */
+	err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops);
+	if (err < 0) {
+		put_device(&dev->dev);
+		return err;
+	}
+	
+	if (result)
+		*result = dev;
+
+	return 0;
+}
+EXPORT_SYMBOL(snd_seq_device_new);
+
+/*
+ * driver registration
+ */
+int __snd_seq_driver_register(struct snd_seq_driver *drv, struct module *mod)
+{
+	if (WARN_ON(!drv->driver.name || !drv->id))
+		return -EINVAL;
+	drv->driver.bus = &snd_seq_bus_type;
+	drv->driver.owner = mod;
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__snd_seq_driver_register);
+
+void snd_seq_driver_unregister(struct snd_seq_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(snd_seq_driver_unregister);
+
+/*
+ * module part
+ */
+
+static int __init seq_dev_proc_init(void)
+{
+#ifdef CONFIG_SND_PROC_FS
+	info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers",
+						  snd_seq_root);
+	if (info_entry == NULL)
+		return -ENOMEM;
+	info_entry->content = SNDRV_INFO_CONTENT_TEXT;
+	info_entry->c.text.read = snd_seq_device_info;
+	if (snd_info_register(info_entry) < 0) {
+		snd_info_free_entry(info_entry);
+		return -ENOMEM;
+	}
+#endif
+	return 0;
+}
+
+static int __init alsa_seq_device_init(void)
+{
+	int err;
+
+	err = bus_register(&snd_seq_bus_type);
+	if (err < 0)
+		return err;
+	err = seq_dev_proc_init();
+	if (err < 0)
+		bus_unregister(&snd_seq_bus_type);
+	return err;
+}
+
+static void __exit alsa_seq_device_exit(void)
+{
+#ifdef CONFIG_MODULES
+	cancel_work_sync(&autoload_work);
+#endif
+#ifdef CONFIG_SND_PROC_FS
+	snd_info_free_entry(info_entry);
+#endif
+	bus_unregister(&snd_seq_bus_type);
+}
+
+subsys_initcall(alsa_seq_device_init)
+module_exit(alsa_seq_device_exit)
diff --git a/sound/core/sound.c b/sound/core/sound.c
new file mode 100644
index 0000000000..df5571d986
--- /dev/null
+++ b/sound/core/sound.c
@@ -0,0 +1,427 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Advanced Linux Sound Architecture
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/info.h>
+#include <sound/control.h>
+#include <sound/initval.h>
+#include <linux/kmod.h>
+#include <linux/mutex.h>
+
+static int major = CONFIG_SND_MAJOR;
+int snd_major;
+EXPORT_SYMBOL(snd_major);
+
+static int cards_limit = 1;
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
+MODULE_LICENSE("GPL");
+module_param(major, int, 0444);
+MODULE_PARM_DESC(major, "Major # for sound driver.");
+module_param(cards_limit, int, 0444);
+MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
+MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
+
+/* this one holds the actual max. card number currently available.
+ * as default, it's identical with cards_limit option.  when more
+ * modules are loaded manually, this limit number increases, too.
+ */
+int snd_ecards_limit;
+EXPORT_SYMBOL(snd_ecards_limit);
+
+#ifdef CONFIG_SND_DEBUG
+struct dentry *sound_debugfs_root;
+EXPORT_SYMBOL_GPL(sound_debugfs_root);
+#endif
+
+static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
+static DEFINE_MUTEX(sound_mutex);
+
+#ifdef CONFIG_MODULES
+
+/**
+ * snd_request_card - try to load the card module
+ * @card: the card number
+ *
+ * Tries to load the module "snd-card-X" for the given card number
+ * via request_module.  Returns immediately if already loaded.
+ */
+void snd_request_card(int card)
+{
+	if (snd_card_locked(card))
+		return;
+	if (card < 0 || card >= cards_limit)
+		return;
+	request_module("snd-card-%i", card);
+}
+EXPORT_SYMBOL(snd_request_card);
+
+static void snd_request_other(int minor)
+{
+	char *str;
+
+	switch (minor) {
+	case SNDRV_MINOR_SEQUENCER:	str = "snd-seq";	break;
+	case SNDRV_MINOR_TIMER:		str = "snd-timer";	break;
+	default:			return;
+	}
+	request_module(str);
+}
+
+#endif	/* modular kernel */
+
+/**
+ * snd_lookup_minor_data - get user data of a registered device
+ * @minor: the minor number
+ * @type: device type (SNDRV_DEVICE_TYPE_XXX)
+ *
+ * Checks that a minor device with the specified type is registered, and returns
+ * its user data pointer.
+ *
+ * This function increments the reference counter of the card instance
+ * if an associated instance with the given minor number and type is found.
+ * The caller must call snd_card_unref() appropriately later.
+ *
+ * Return: The user data pointer if the specified device is found. %NULL
+ * otherwise.
+ */
+void *snd_lookup_minor_data(unsigned int minor, int type)
+{
+	struct snd_minor *mreg;
+	void *private_data;
+
+	if (minor >= ARRAY_SIZE(snd_minors))
+		return NULL;
+	mutex_lock(&sound_mutex);
+	mreg = snd_minors[minor];
+	if (mreg && mreg->type == type) {
+		private_data = mreg->private_data;
+		if (private_data && mreg->card_ptr)
+			get_device(&mreg->card_ptr->card_dev);
+	} else
+		private_data = NULL;
+	mutex_unlock(&sound_mutex);
+	return private_data;
+}
+EXPORT_SYMBOL(snd_lookup_minor_data);
+
+#ifdef CONFIG_MODULES
+static struct snd_minor *autoload_device(unsigned int minor)
+{
+	int dev;
+	mutex_unlock(&sound_mutex); /* release lock temporarily */
+	dev = SNDRV_MINOR_DEVICE(minor);
+	if (dev == SNDRV_MINOR_CONTROL) {
+		/* /dev/aloadC? */
+		int card = SNDRV_MINOR_CARD(minor);
+		struct snd_card *ref = snd_card_ref(card);
+		if (!ref)
+			snd_request_card(card);
+		else
+			snd_card_unref(ref);
+	} else if (dev == SNDRV_MINOR_GLOBAL) {
+		/* /dev/aloadSEQ */
+		snd_request_other(minor);
+	}
+	mutex_lock(&sound_mutex); /* reacuire lock */
+	return snd_minors[minor];
+}
+#else /* !CONFIG_MODULES */
+#define autoload_device(minor)	NULL
+#endif /* CONFIG_MODULES */
+
+static int snd_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	struct snd_minor *mptr = NULL;
+	const struct file_operations *new_fops;
+	int err = 0;
+
+	if (minor >= ARRAY_SIZE(snd_minors))
+		return -ENODEV;
+	mutex_lock(&sound_mutex);
+	mptr = snd_minors[minor];
+	if (mptr == NULL) {
+		mptr = autoload_device(minor);
+		if (!mptr) {
+			mutex_unlock(&sound_mutex);
+			return -ENODEV;
+		}
+	}
+	new_fops = fops_get(mptr->f_ops);
+	mutex_unlock(&sound_mutex);
+	if (!new_fops)
+		return -ENODEV;
+	replace_fops(file, new_fops);
+
+	if (file->f_op->open)
+		err = file->f_op->open(inode, file);
+	return err;
+}
+
+static const struct file_operations snd_fops =
+{
+	.owner =	THIS_MODULE,
+	.open =		snd_open,
+	.llseek =	noop_llseek,
+};
+
+#ifdef CONFIG_SND_DYNAMIC_MINORS
+static int snd_find_free_minor(int type, struct snd_card *card, int dev)
+{
+	int minor;
+
+	/* static minors for module auto loading */
+	if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
+		return SNDRV_MINOR_SEQUENCER;
+	if (type == SNDRV_DEVICE_TYPE_TIMER)
+		return SNDRV_MINOR_TIMER;
+
+	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
+		/* skip static minors still used for module auto loading */
+		if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
+			continue;
+		if (minor == SNDRV_MINOR_SEQUENCER ||
+		    minor == SNDRV_MINOR_TIMER)
+			continue;
+		if (!snd_minors[minor])
+			return minor;
+	}
+	return -EBUSY;
+}
+#else
+static int snd_find_free_minor(int type, struct snd_card *card, int dev)
+{
+	int minor;
+
+	switch (type) {
+	case SNDRV_DEVICE_TYPE_SEQUENCER:
+	case SNDRV_DEVICE_TYPE_TIMER:
+		minor = type;
+		break;
+	case SNDRV_DEVICE_TYPE_CONTROL:
+		if (snd_BUG_ON(!card))
+			return -EINVAL;
+		minor = SNDRV_MINOR(card->number, type);
+		break;
+	case SNDRV_DEVICE_TYPE_HWDEP:
+	case SNDRV_DEVICE_TYPE_RAWMIDI:
+	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
+	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
+	case SNDRV_DEVICE_TYPE_COMPRESS:
+		if (snd_BUG_ON(!card))
+			return -EINVAL;
+		minor = SNDRV_MINOR(card->number, type + dev);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
+		return -EINVAL;
+	if (snd_minors[minor])
+		return -EBUSY;
+	return minor;
+}
+#endif
+
+/**
+ * snd_register_device - Register the ALSA device file for the card
+ * @type: the device type, SNDRV_DEVICE_TYPE_XXX
+ * @card: the card instance
+ * @dev: the device index
+ * @f_ops: the file operations
+ * @private_data: user pointer for f_ops->open()
+ * @device: the device to register
+ *
+ * Registers an ALSA device file for the given card.
+ * The operators have to be set in reg parameter.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_register_device(int type, struct snd_card *card, int dev,
+			const struct file_operations *f_ops,
+			void *private_data, struct device *device)
+{
+	int minor;
+	int err = 0;
+	struct snd_minor *preg;
+
+	if (snd_BUG_ON(!device))
+		return -EINVAL;
+
+	preg = kmalloc(sizeof *preg, GFP_KERNEL);
+	if (preg == NULL)
+		return -ENOMEM;
+	preg->type = type;
+	preg->card = card ? card->number : -1;
+	preg->device = dev;
+	preg->f_ops = f_ops;
+	preg->private_data = private_data;
+	preg->card_ptr = card;
+	mutex_lock(&sound_mutex);
+	minor = snd_find_free_minor(type, card, dev);
+	if (minor < 0) {
+		err = minor;
+		goto error;
+	}
+
+	preg->dev = device;
+	device->devt = MKDEV(major, minor);
+	err = device_add(device);
+	if (err < 0)
+		goto error;
+
+	snd_minors[minor] = preg;
+ error:
+	mutex_unlock(&sound_mutex);
+	if (err < 0)
+		kfree(preg);
+	return err;
+}
+EXPORT_SYMBOL(snd_register_device);
+
+/**
+ * snd_unregister_device - unregister the device on the given card
+ * @dev: the device instance
+ *
+ * Unregisters the device file already registered via
+ * snd_register_device().
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_unregister_device(struct device *dev)
+{
+	int minor;
+	struct snd_minor *preg;
+
+	mutex_lock(&sound_mutex);
+	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
+		preg = snd_minors[minor];
+		if (preg && preg->dev == dev) {
+			snd_minors[minor] = NULL;
+			device_del(dev);
+			kfree(preg);
+			break;
+		}
+	}
+	mutex_unlock(&sound_mutex);
+	if (minor >= ARRAY_SIZE(snd_minors))
+		return -ENOENT;
+	return 0;
+}
+EXPORT_SYMBOL(snd_unregister_device);
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ *  INFO PART
+ */
+static const char *snd_device_type_name(int type)
+{
+	switch (type) {
+	case SNDRV_DEVICE_TYPE_CONTROL:
+		return "control";
+	case SNDRV_DEVICE_TYPE_HWDEP:
+		return "hardware dependent";
+	case SNDRV_DEVICE_TYPE_RAWMIDI:
+		return "raw midi";
+	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
+		return "digital audio playback";
+	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
+		return "digital audio capture";
+	case SNDRV_DEVICE_TYPE_SEQUENCER:
+		return "sequencer";
+	case SNDRV_DEVICE_TYPE_TIMER:
+		return "timer";
+	case SNDRV_DEVICE_TYPE_COMPRESS:
+		return "compress";
+	default:
+		return "?";
+	}
+}
+
+static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
+{
+	int minor;
+	struct snd_minor *mptr;
+
+	mutex_lock(&sound_mutex);
+	for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
+		mptr = snd_minors[minor];
+		if (!mptr)
+			continue;
+		if (mptr->card >= 0) {
+			if (mptr->device >= 0)
+				snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
+					    minor, mptr->card, mptr->device,
+					    snd_device_type_name(mptr->type));
+			else
+				snd_iprintf(buffer, "%3i: [%2i]   : %s\n",
+					    minor, mptr->card,
+					    snd_device_type_name(mptr->type));
+		} else
+			snd_iprintf(buffer, "%3i:        : %s\n", minor,
+				    snd_device_type_name(mptr->type));
+	}
+	mutex_unlock(&sound_mutex);
+}
+
+int __init snd_minor_info_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_minor_info_read;
+	return snd_info_register(entry); /* freed in error path */
+}
+#endif /* CONFIG_SND_PROC_FS */
+
+/*
+ *  INIT PART
+ */
+
+static int __init alsa_sound_init(void)
+{
+	snd_major = major;
+	snd_ecards_limit = cards_limit;
+	if (register_chrdev(major, "alsa", &snd_fops)) {
+		pr_err("ALSA core: unable to register native major device number %d\n", major);
+		return -EIO;
+	}
+	if (snd_info_init() < 0) {
+		unregister_chrdev(major, "alsa");
+		return -ENOMEM;
+	}
+
+#ifdef CONFIG_SND_DEBUG
+	sound_debugfs_root = debugfs_create_dir("sound", NULL);
+#endif
+#ifndef MODULE
+	pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
+#endif
+	return 0;
+}
+
+static void __exit alsa_sound_exit(void)
+{
+#ifdef CONFIG_SND_DEBUG
+	debugfs_remove(sound_debugfs_root);
+#endif
+	snd_info_done();
+	unregister_chrdev(major, "alsa");
+}
+
+subsys_initcall(alsa_sound_init);
+module_exit(alsa_sound_exit);
diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c
new file mode 100644
index 0000000000..2751bf2ff6
--- /dev/null
+++ b/sound/core/sound_oss.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Advanced Linux Sound Architecture
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/info.h>
+#include <linux/sound.h>
+#include <linux/mutex.h>
+
+#define SNDRV_OSS_MINORS 256
+
+static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
+static DEFINE_MUTEX(sound_oss_mutex);
+
+/* NOTE: This function increments the refcount of the associated card like
+ * snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
+ */
+void *snd_lookup_oss_minor_data(unsigned int minor, int type)
+{
+	struct snd_minor *mreg;
+	void *private_data;
+
+	if (minor >= ARRAY_SIZE(snd_oss_minors))
+		return NULL;
+	mutex_lock(&sound_oss_mutex);
+	mreg = snd_oss_minors[minor];
+	if (mreg && mreg->type == type) {
+		private_data = mreg->private_data;
+		if (private_data && mreg->card_ptr)
+			get_device(&mreg->card_ptr->card_dev);
+	} else
+		private_data = NULL;
+	mutex_unlock(&sound_oss_mutex);
+	return private_data;
+}
+EXPORT_SYMBOL(snd_lookup_oss_minor_data);
+
+static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
+{
+	int minor;
+
+	switch (type) {
+	case SNDRV_OSS_DEVICE_TYPE_MIXER:
+		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
+			return -EINVAL;
+		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
+		break;
+	case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
+		minor = SNDRV_MINOR_OSS_SEQUENCER;
+		break;
+	case SNDRV_OSS_DEVICE_TYPE_MUSIC:
+		minor = SNDRV_MINOR_OSS_MUSIC;
+		break;
+	case SNDRV_OSS_DEVICE_TYPE_PCM:
+		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
+			return -EINVAL;
+		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
+		break;
+	case SNDRV_OSS_DEVICE_TYPE_MIDI:
+		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
+			return -EINVAL;
+		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
+		break;
+	case SNDRV_OSS_DEVICE_TYPE_DMFM:
+		minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
+		break;
+	case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
+		minor = SNDRV_MINOR_OSS_SNDSTAT;
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (minor < 0 || minor >= SNDRV_OSS_MINORS)
+		return -EINVAL;
+	return minor;
+}
+
+int snd_register_oss_device(int type, struct snd_card *card, int dev,
+			    const struct file_operations *f_ops, void *private_data)
+{
+	int minor = snd_oss_kernel_minor(type, card, dev);
+	int minor_unit;
+	struct snd_minor *preg;
+	int cidx = SNDRV_MINOR_OSS_CARD(minor);
+	int track2 = -1;
+	int register1 = -1, register2 = -1;
+	struct device *carddev = snd_card_get_device_link(card);
+
+	if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
+		return 0; /* ignore silently */
+	if (minor < 0)
+		return minor;
+	preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
+	if (preg == NULL)
+		return -ENOMEM;
+	preg->type = type;
+	preg->card = card ? card->number : -1;
+	preg->device = dev;
+	preg->f_ops = f_ops;
+	preg->private_data = private_data;
+	preg->card_ptr = card;
+	mutex_lock(&sound_oss_mutex);
+	snd_oss_minors[minor] = preg;
+	minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
+	switch (minor_unit) {
+	case SNDRV_MINOR_OSS_PCM:
+		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
+		break;
+	case SNDRV_MINOR_OSS_MIDI:
+		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
+		break;
+	case SNDRV_MINOR_OSS_MIDI1:
+		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
+		break;
+	}
+	register1 = register_sound_special_device(f_ops, minor, carddev);
+	if (register1 != minor)
+		goto __end;
+	if (track2 >= 0) {
+		register2 = register_sound_special_device(f_ops, track2,
+							  carddev);
+		if (register2 != track2)
+			goto __end;
+		snd_oss_minors[track2] = preg;
+	}
+	mutex_unlock(&sound_oss_mutex);
+	return 0;
+
+      __end:
+      	if (register2 >= 0)
+      		unregister_sound_special(register2);
+      	if (register1 >= 0)
+      		unregister_sound_special(register1);
+	snd_oss_minors[minor] = NULL;
+	mutex_unlock(&sound_oss_mutex);
+	kfree(preg);
+      	return -EBUSY;
+}
+EXPORT_SYMBOL(snd_register_oss_device);
+
+int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
+{
+	int minor = snd_oss_kernel_minor(type, card, dev);
+	int cidx = SNDRV_MINOR_OSS_CARD(minor);
+	int track2 = -1;
+	struct snd_minor *mptr;
+
+	if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
+		return 0;
+	if (minor < 0)
+		return minor;
+	mutex_lock(&sound_oss_mutex);
+	mptr = snd_oss_minors[minor];
+	if (mptr == NULL) {
+		mutex_unlock(&sound_oss_mutex);
+		return -ENOENT;
+	}
+	switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
+	case SNDRV_MINOR_OSS_PCM:
+		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
+		break;
+	case SNDRV_MINOR_OSS_MIDI:
+		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
+		break;
+	case SNDRV_MINOR_OSS_MIDI1:
+		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
+		break;
+	}
+	if (track2 >= 0)
+		snd_oss_minors[track2] = NULL;
+	snd_oss_minors[minor] = NULL;
+	mutex_unlock(&sound_oss_mutex);
+
+	/* call unregister_sound_special() outside sound_oss_mutex;
+	 * otherwise may deadlock, as it can trigger the release of a card
+	 */
+	unregister_sound_special(minor);
+	if (track2 >= 0)
+		unregister_sound_special(track2);
+
+	kfree(mptr);
+	return 0;
+}
+EXPORT_SYMBOL(snd_unregister_oss_device);
+
+/*
+ *  INFO PART
+ */
+
+#ifdef CONFIG_SND_PROC_FS
+static const char *snd_oss_device_type_name(int type)
+{
+	switch (type) {
+	case SNDRV_OSS_DEVICE_TYPE_MIXER:
+		return "mixer";
+	case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
+	case SNDRV_OSS_DEVICE_TYPE_MUSIC:
+		return "sequencer";
+	case SNDRV_OSS_DEVICE_TYPE_PCM:
+		return "digital audio";
+	case SNDRV_OSS_DEVICE_TYPE_MIDI:
+		return "raw midi";
+	case SNDRV_OSS_DEVICE_TYPE_DMFM:
+		return "hardware dependent";
+	default:
+		return "?";
+	}
+}
+
+static void snd_minor_info_oss_read(struct snd_info_entry *entry,
+				    struct snd_info_buffer *buffer)
+{
+	int minor;
+	struct snd_minor *mptr;
+
+	mutex_lock(&sound_oss_mutex);
+	for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
+		mptr = snd_oss_minors[minor];
+		if (!mptr)
+			continue;
+		if (mptr->card >= 0)
+			snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
+				    mptr->card, mptr->device,
+				    snd_oss_device_type_name(mptr->type));
+		else
+			snd_iprintf(buffer, "%3i:       : %s\n", minor,
+				    snd_oss_device_type_name(mptr->type));
+	}
+	mutex_unlock(&sound_oss_mutex);
+}
+
+
+int __init snd_minor_info_oss_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
+	if (!entry)
+		return -ENOMEM;
+	entry->c.text.read = snd_minor_info_oss_read;
+	return snd_info_register(entry); /* freed in error path */
+}
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/timer.c b/sound/core/timer.c
new file mode 100644
index 0000000000..e6e551d4a2
--- /dev/null
+++ b/sound/core/timer.c
@@ -0,0 +1,2358 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Timers abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/sched/signal.h>
+#include <sound/core.h>
+#include <sound/timer.h>
+#include <sound/control.h>
+#include <sound/info.h>
+#include <sound/minors.h>
+#include <sound/initval.h>
+#include <linux/kmod.h>
+
+/* internal flags */
+#define SNDRV_TIMER_IFLG_PAUSED		0x00010000
+#define SNDRV_TIMER_IFLG_DEAD		0x00020000
+
+#if IS_ENABLED(CONFIG_SND_HRTIMER)
+#define DEFAULT_TIMER_LIMIT 4
+#else
+#define DEFAULT_TIMER_LIMIT 1
+#endif
+
+static int timer_limit = DEFAULT_TIMER_LIMIT;
+static int timer_tstamp_monotonic = 1;
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA timer interface");
+MODULE_LICENSE("GPL");
+module_param(timer_limit, int, 0444);
+MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
+module_param(timer_tstamp_monotonic, int, 0444);
+MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
+
+MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
+MODULE_ALIAS("devname:snd/timer");
+
+enum timer_tread_format {
+	TREAD_FORMAT_NONE = 0,
+	TREAD_FORMAT_TIME64,
+	TREAD_FORMAT_TIME32,
+};
+
+struct snd_timer_tread32 {
+	int event;
+	s32 tstamp_sec;
+	s32 tstamp_nsec;
+	unsigned int val;
+};
+
+struct snd_timer_tread64 {
+	int event;
+	u8 pad1[4];
+	s64 tstamp_sec;
+	s64 tstamp_nsec;
+	unsigned int val;
+	u8 pad2[4];
+};
+
+struct snd_timer_user {
+	struct snd_timer_instance *timeri;
+	int tread;		/* enhanced read with timestamps and events */
+	unsigned long ticks;
+	unsigned long overrun;
+	int qhead;
+	int qtail;
+	int qused;
+	int queue_size;
+	bool disconnected;
+	struct snd_timer_read *queue;
+	struct snd_timer_tread64 *tqueue;
+	spinlock_t qlock;
+	unsigned long last_resolution;
+	unsigned int filter;
+	struct timespec64 tstamp;		/* trigger tstamp */
+	wait_queue_head_t qchange_sleep;
+	struct snd_fasync *fasync;
+	struct mutex ioctl_lock;
+};
+
+struct snd_timer_status32 {
+	s32 tstamp_sec;			/* Timestamp - last update */
+	s32 tstamp_nsec;
+	unsigned int resolution;	/* current period resolution in ns */
+	unsigned int lost;		/* counter of master tick lost */
+	unsigned int overrun;		/* count of read queue overruns */
+	unsigned int queue;		/* used queue size */
+	unsigned char reserved[64];	/* reserved */
+};
+
+#define SNDRV_TIMER_IOCTL_STATUS32	_IOR('T', 0x14, struct snd_timer_status32)
+
+struct snd_timer_status64 {
+	s64 tstamp_sec;			/* Timestamp - last update */
+	s64 tstamp_nsec;
+	unsigned int resolution;	/* current period resolution in ns */
+	unsigned int lost;		/* counter of master tick lost */
+	unsigned int overrun;		/* count of read queue overruns */
+	unsigned int queue;		/* used queue size */
+	unsigned char reserved[64];	/* reserved */
+};
+
+#define SNDRV_TIMER_IOCTL_STATUS64	_IOR('T', 0x14, struct snd_timer_status64)
+
+/* list of timers */
+static LIST_HEAD(snd_timer_list);
+
+/* list of slave instances */
+static LIST_HEAD(snd_timer_slave_list);
+
+/* lock for slave active lists */
+static DEFINE_SPINLOCK(slave_active_lock);
+
+#define MAX_SLAVE_INSTANCES	1000
+static int num_slaves;
+
+static DEFINE_MUTEX(register_mutex);
+
+static int snd_timer_free(struct snd_timer *timer);
+static int snd_timer_dev_free(struct snd_device *device);
+static int snd_timer_dev_register(struct snd_device *device);
+static int snd_timer_dev_disconnect(struct snd_device *device);
+
+static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
+
+/*
+ * create a timer instance with the given owner string.
+ */
+struct snd_timer_instance *snd_timer_instance_new(const char *owner)
+{
+	struct snd_timer_instance *timeri;
+
+	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
+	if (timeri == NULL)
+		return NULL;
+	timeri->owner = kstrdup(owner, GFP_KERNEL);
+	if (! timeri->owner) {
+		kfree(timeri);
+		return NULL;
+	}
+	INIT_LIST_HEAD(&timeri->open_list);
+	INIT_LIST_HEAD(&timeri->active_list);
+	INIT_LIST_HEAD(&timeri->ack_list);
+	INIT_LIST_HEAD(&timeri->slave_list_head);
+	INIT_LIST_HEAD(&timeri->slave_active_head);
+
+	return timeri;
+}
+EXPORT_SYMBOL(snd_timer_instance_new);
+
+void snd_timer_instance_free(struct snd_timer_instance *timeri)
+{
+	if (timeri) {
+		if (timeri->private_free)
+			timeri->private_free(timeri);
+		kfree(timeri->owner);
+		kfree(timeri);
+	}
+}
+EXPORT_SYMBOL(snd_timer_instance_free);
+
+/*
+ * find a timer instance from the given timer id
+ */
+static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
+{
+	struct snd_timer *timer;
+
+	list_for_each_entry(timer, &snd_timer_list, device_list) {
+		if (timer->tmr_class != tid->dev_class)
+			continue;
+		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
+		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
+		    (timer->card == NULL ||
+		     timer->card->number != tid->card))
+			continue;
+		if (timer->tmr_device != tid->device)
+			continue;
+		if (timer->tmr_subdevice != tid->subdevice)
+			continue;
+		return timer;
+	}
+	return NULL;
+}
+
+#ifdef CONFIG_MODULES
+
+static void snd_timer_request(struct snd_timer_id *tid)
+{
+	switch (tid->dev_class) {
+	case SNDRV_TIMER_CLASS_GLOBAL:
+		if (tid->device < timer_limit)
+			request_module("snd-timer-%i", tid->device);
+		break;
+	case SNDRV_TIMER_CLASS_CARD:
+	case SNDRV_TIMER_CLASS_PCM:
+		if (tid->card < snd_ecards_limit)
+			request_module("snd-card-%i", tid->card);
+		break;
+	default:
+		break;
+	}
+}
+
+#endif
+
+/* move the slave if it belongs to the master; return 1 if match */
+static int check_matching_master_slave(struct snd_timer_instance *master,
+				       struct snd_timer_instance *slave)
+{
+	if (slave->slave_class != master->slave_class ||
+	    slave->slave_id != master->slave_id)
+		return 0;
+	if (master->timer->num_instances >= master->timer->max_instances)
+		return -EBUSY;
+	list_move_tail(&slave->open_list, &master->slave_list_head);
+	master->timer->num_instances++;
+	spin_lock_irq(&slave_active_lock);
+	spin_lock(&master->timer->lock);
+	slave->master = master;
+	slave->timer = master->timer;
+	if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
+		list_add_tail(&slave->active_list, &master->slave_active_head);
+	spin_unlock(&master->timer->lock);
+	spin_unlock_irq(&slave_active_lock);
+	return 1;
+}
+
+/*
+ * look for a master instance matching with the slave id of the given slave.
+ * when found, relink the open_link of the slave.
+ *
+ * call this with register_mutex down.
+ */
+static int snd_timer_check_slave(struct snd_timer_instance *slave)
+{
+	struct snd_timer *timer;
+	struct snd_timer_instance *master;
+	int err = 0;
+
+	/* FIXME: it's really dumb to look up all entries.. */
+	list_for_each_entry(timer, &snd_timer_list, device_list) {
+		list_for_each_entry(master, &timer->open_list_head, open_list) {
+			err = check_matching_master_slave(master, slave);
+			if (err != 0) /* match found or error */
+				goto out;
+		}
+	}
+ out:
+	return err < 0 ? err : 0;
+}
+
+/*
+ * look for slave instances matching with the slave id of the given master.
+ * when found, relink the open_link of slaves.
+ *
+ * call this with register_mutex down.
+ */
+static int snd_timer_check_master(struct snd_timer_instance *master)
+{
+	struct snd_timer_instance *slave, *tmp;
+	int err = 0;
+
+	/* check all pending slaves */
+	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
+		err = check_matching_master_slave(master, slave);
+		if (err < 0)
+			break;
+	}
+	return err < 0 ? err : 0;
+}
+
+static void snd_timer_close_locked(struct snd_timer_instance *timeri,
+				   struct device **card_devp_to_put);
+
+/*
+ * open a timer instance
+ * when opening a master, the slave id must be here given.
+ */
+int snd_timer_open(struct snd_timer_instance *timeri,
+		   struct snd_timer_id *tid,
+		   unsigned int slave_id)
+{
+	struct snd_timer *timer;
+	struct device *card_dev_to_put = NULL;
+	int err;
+
+	mutex_lock(&register_mutex);
+	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
+		/* open a slave instance */
+		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
+		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
+			pr_debug("ALSA: timer: invalid slave class %i\n",
+				 tid->dev_sclass);
+			err = -EINVAL;
+			goto unlock;
+		}
+		if (num_slaves >= MAX_SLAVE_INSTANCES) {
+			err = -EBUSY;
+			goto unlock;
+		}
+		timeri->slave_class = tid->dev_sclass;
+		timeri->slave_id = tid->device;
+		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
+		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
+		num_slaves++;
+		err = snd_timer_check_slave(timeri);
+		goto list_added;
+	}
+
+	/* open a master instance */
+	timer = snd_timer_find(tid);
+#ifdef CONFIG_MODULES
+	if (!timer) {
+		mutex_unlock(&register_mutex);
+		snd_timer_request(tid);
+		mutex_lock(&register_mutex);
+		timer = snd_timer_find(tid);
+	}
+#endif
+	if (!timer) {
+		err = -ENODEV;
+		goto unlock;
+	}
+	if (!list_empty(&timer->open_list_head)) {
+		struct snd_timer_instance *t =
+			list_entry(timer->open_list_head.next,
+				    struct snd_timer_instance, open_list);
+		if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
+			err = -EBUSY;
+			goto unlock;
+		}
+	}
+	if (timer->num_instances >= timer->max_instances) {
+		err = -EBUSY;
+		goto unlock;
+	}
+	if (!try_module_get(timer->module)) {
+		err = -EBUSY;
+		goto unlock;
+	}
+	/* take a card refcount for safe disconnection */
+	if (timer->card) {
+		get_device(&timer->card->card_dev);
+		card_dev_to_put = &timer->card->card_dev;
+	}
+
+	if (list_empty(&timer->open_list_head) && timer->hw.open) {
+		err = timer->hw.open(timer);
+		if (err) {
+			module_put(timer->module);
+			goto unlock;
+		}
+	}
+
+	timeri->timer = timer;
+	timeri->slave_class = tid->dev_sclass;
+	timeri->slave_id = slave_id;
+
+	list_add_tail(&timeri->open_list, &timer->open_list_head);
+	timer->num_instances++;
+	err = snd_timer_check_master(timeri);
+list_added:
+	if (err < 0)
+		snd_timer_close_locked(timeri, &card_dev_to_put);
+
+ unlock:
+	mutex_unlock(&register_mutex);
+	/* put_device() is called after unlock for avoiding deadlock */
+	if (err < 0 && card_dev_to_put)
+		put_device(card_dev_to_put);
+	return err;
+}
+EXPORT_SYMBOL(snd_timer_open);
+
+/*
+ * close a timer instance
+ * call this with register_mutex down.
+ */
+static void snd_timer_close_locked(struct snd_timer_instance *timeri,
+				   struct device **card_devp_to_put)
+{
+	struct snd_timer *timer = timeri->timer;
+	struct snd_timer_instance *slave, *tmp;
+
+	if (timer) {
+		spin_lock_irq(&timer->lock);
+		timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
+		spin_unlock_irq(&timer->lock);
+	}
+
+	if (!list_empty(&timeri->open_list)) {
+		list_del_init(&timeri->open_list);
+		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+			num_slaves--;
+	}
+
+	/* force to stop the timer */
+	snd_timer_stop(timeri);
+
+	if (timer) {
+		timer->num_instances--;
+		/* wait, until the active callback is finished */
+		spin_lock_irq(&timer->lock);
+		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
+			spin_unlock_irq(&timer->lock);
+			udelay(10);
+			spin_lock_irq(&timer->lock);
+		}
+		spin_unlock_irq(&timer->lock);
+
+		/* remove slave links */
+		spin_lock_irq(&slave_active_lock);
+		spin_lock(&timer->lock);
+		timeri->timer = NULL;
+		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
+					 open_list) {
+			list_move_tail(&slave->open_list, &snd_timer_slave_list);
+			timer->num_instances--;
+			slave->master = NULL;
+			slave->timer = NULL;
+			list_del_init(&slave->ack_list);
+			list_del_init(&slave->active_list);
+		}
+		spin_unlock(&timer->lock);
+		spin_unlock_irq(&slave_active_lock);
+
+		/* slave doesn't need to release timer resources below */
+		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+			timer = NULL;
+	}
+
+	if (timer) {
+		if (list_empty(&timer->open_list_head) && timer->hw.close)
+			timer->hw.close(timer);
+		/* release a card refcount for safe disconnection */
+		if (timer->card)
+			*card_devp_to_put = &timer->card->card_dev;
+		module_put(timer->module);
+	}
+}
+
+/*
+ * close a timer instance
+ */
+void snd_timer_close(struct snd_timer_instance *timeri)
+{
+	struct device *card_dev_to_put = NULL;
+
+	if (snd_BUG_ON(!timeri))
+		return;
+
+	mutex_lock(&register_mutex);
+	snd_timer_close_locked(timeri, &card_dev_to_put);
+	mutex_unlock(&register_mutex);
+	/* put_device() is called after unlock for avoiding deadlock */
+	if (card_dev_to_put)
+		put_device(card_dev_to_put);
+}
+EXPORT_SYMBOL(snd_timer_close);
+
+static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
+{
+	if (timer->hw.c_resolution)
+		return timer->hw.c_resolution(timer);
+	else
+		return timer->hw.resolution;
+}
+
+unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
+{
+	struct snd_timer * timer;
+	unsigned long ret = 0;
+	unsigned long flags;
+
+	if (timeri == NULL)
+		return 0;
+	timer = timeri->timer;
+	if (timer) {
+		spin_lock_irqsave(&timer->lock, flags);
+		ret = snd_timer_hw_resolution(timer);
+		spin_unlock_irqrestore(&timer->lock, flags);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(snd_timer_resolution);
+
+static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
+{
+	struct snd_timer *timer = ti->timer;
+	unsigned long resolution = 0;
+	struct snd_timer_instance *ts;
+	struct timespec64 tstamp;
+
+	if (timer_tstamp_monotonic)
+		ktime_get_ts64(&tstamp);
+	else
+		ktime_get_real_ts64(&tstamp);
+	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
+		       event > SNDRV_TIMER_EVENT_PAUSE))
+		return;
+	if (timer &&
+	    (event == SNDRV_TIMER_EVENT_START ||
+	     event == SNDRV_TIMER_EVENT_CONTINUE))
+		resolution = snd_timer_hw_resolution(timer);
+	if (ti->ccallback)
+		ti->ccallback(ti, event, &tstamp, resolution);
+	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return;
+	if (timer == NULL)
+		return;
+	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
+		return;
+	event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
+	list_for_each_entry(ts, &ti->slave_active_head, active_list)
+		if (ts->ccallback)
+			ts->ccallback(ts, event, &tstamp, resolution);
+}
+
+/* start/continue a master timer */
+static int snd_timer_start1(struct snd_timer_instance *timeri,
+			    bool start, unsigned long ticks)
+{
+	struct snd_timer *timer;
+	int result;
+	unsigned long flags;
+
+	timer = timeri->timer;
+	if (!timer)
+		return -EINVAL;
+
+	spin_lock_irqsave(&timer->lock, flags);
+	if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
+		result = -EINVAL;
+		goto unlock;
+	}
+	if (timer->card && timer->card->shutdown) {
+		result = -ENODEV;
+		goto unlock;
+	}
+	if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
+			     SNDRV_TIMER_IFLG_START)) {
+		result = -EBUSY;
+		goto unlock;
+	}
+
+	if (start)
+		timeri->ticks = timeri->cticks = ticks;
+	else if (!timeri->cticks)
+		timeri->cticks = 1;
+	timeri->pticks = 0;
+
+	list_move_tail(&timeri->active_list, &timer->active_list_head);
+	if (timer->running) {
+		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			goto __start_now;
+		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
+		timeri->flags |= SNDRV_TIMER_IFLG_START;
+		result = 1; /* delayed start */
+	} else {
+		if (start)
+			timer->sticks = ticks;
+		timer->hw.start(timer);
+	      __start_now:
+		timer->running++;
+		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
+		result = 0;
+	}
+	snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
+			  SNDRV_TIMER_EVENT_CONTINUE);
+ unlock:
+	spin_unlock_irqrestore(&timer->lock, flags);
+	return result;
+}
+
+/* start/continue a slave timer */
+static int snd_timer_start_slave(struct snd_timer_instance *timeri,
+				 bool start)
+{
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&slave_active_lock, flags);
+	if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
+		err = -EINVAL;
+		goto unlock;
+	}
+	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
+		err = -EBUSY;
+		goto unlock;
+	}
+	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
+	if (timeri->master && timeri->timer) {
+		spin_lock(&timeri->timer->lock);
+		list_add_tail(&timeri->active_list,
+			      &timeri->master->slave_active_head);
+		snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
+				  SNDRV_TIMER_EVENT_CONTINUE);
+		spin_unlock(&timeri->timer->lock);
+	}
+	err = 1; /* delayed start */
+ unlock:
+	spin_unlock_irqrestore(&slave_active_lock, flags);
+	return err;
+}
+
+/* stop/pause a master timer */
+static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
+{
+	struct snd_timer *timer;
+	int result = 0;
+	unsigned long flags;
+
+	timer = timeri->timer;
+	if (!timer)
+		return -EINVAL;
+	spin_lock_irqsave(&timer->lock, flags);
+	list_del_init(&timeri->ack_list);
+	list_del_init(&timeri->active_list);
+	if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
+			       SNDRV_TIMER_IFLG_START))) {
+		result = -EBUSY;
+		goto unlock;
+	}
+	if (timer->card && timer->card->shutdown)
+		goto unlock;
+	if (stop) {
+		timeri->cticks = timeri->ticks;
+		timeri->pticks = 0;
+	}
+	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
+	    !(--timer->running)) {
+		timer->hw.stop(timer);
+		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
+			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
+			snd_timer_reschedule(timer, 0);
+			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
+				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
+				timer->hw.start(timer);
+			}
+		}
+	}
+	timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
+	if (stop)
+		timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
+	else
+		timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
+	snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
+			  SNDRV_TIMER_EVENT_PAUSE);
+ unlock:
+	spin_unlock_irqrestore(&timer->lock, flags);
+	return result;
+}
+
+/* stop/pause a slave timer */
+static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
+{
+	unsigned long flags;
+	bool running;
+
+	spin_lock_irqsave(&slave_active_lock, flags);
+	running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
+	timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
+	if (timeri->timer) {
+		spin_lock(&timeri->timer->lock);
+		list_del_init(&timeri->ack_list);
+		list_del_init(&timeri->active_list);
+		if (running)
+			snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
+					  SNDRV_TIMER_EVENT_PAUSE);
+		spin_unlock(&timeri->timer->lock);
+	}
+	spin_unlock_irqrestore(&slave_active_lock, flags);
+	return running ? 0 : -EBUSY;
+}
+
+/*
+ *  start the timer instance
+ */
+int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
+{
+	if (timeri == NULL || ticks < 1)
+		return -EINVAL;
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return snd_timer_start_slave(timeri, true);
+	else
+		return snd_timer_start1(timeri, true, ticks);
+}
+EXPORT_SYMBOL(snd_timer_start);
+
+/*
+ * stop the timer instance.
+ *
+ * do not call this from the timer callback!
+ */
+int snd_timer_stop(struct snd_timer_instance *timeri)
+{
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return snd_timer_stop_slave(timeri, true);
+	else
+		return snd_timer_stop1(timeri, true);
+}
+EXPORT_SYMBOL(snd_timer_stop);
+
+/*
+ * start again..  the tick is kept.
+ */
+int snd_timer_continue(struct snd_timer_instance *timeri)
+{
+	/* timer can continue only after pause */
+	if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
+		return -EINVAL;
+
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return snd_timer_start_slave(timeri, false);
+	else
+		return snd_timer_start1(timeri, false, 0);
+}
+EXPORT_SYMBOL(snd_timer_continue);
+
+/*
+ * pause.. remember the ticks left
+ */
+int snd_timer_pause(struct snd_timer_instance * timeri)
+{
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return snd_timer_stop_slave(timeri, false);
+	else
+		return snd_timer_stop1(timeri, false);
+}
+EXPORT_SYMBOL(snd_timer_pause);
+
+/*
+ * reschedule the timer
+ *
+ * start pending instances and check the scheduling ticks.
+ * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
+ */
+static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
+{
+	struct snd_timer_instance *ti;
+	unsigned long ticks = ~0UL;
+
+	list_for_each_entry(ti, &timer->active_list_head, active_list) {
+		if (ti->flags & SNDRV_TIMER_IFLG_START) {
+			ti->flags &= ~SNDRV_TIMER_IFLG_START;
+			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
+			timer->running++;
+		}
+		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
+			if (ticks > ti->cticks)
+				ticks = ti->cticks;
+		}
+	}
+	if (ticks == ~0UL) {
+		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
+		return;
+	}
+	if (ticks > timer->hw.ticks)
+		ticks = timer->hw.ticks;
+	if (ticks_left != ticks)
+		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
+	timer->sticks = ticks;
+}
+
+/* call callbacks in timer ack list */
+static void snd_timer_process_callbacks(struct snd_timer *timer,
+					struct list_head *head)
+{
+	struct snd_timer_instance *ti;
+	unsigned long resolution, ticks;
+
+	while (!list_empty(head)) {
+		ti = list_first_entry(head, struct snd_timer_instance,
+				      ack_list);
+
+		/* remove from ack_list and make empty */
+		list_del_init(&ti->ack_list);
+
+		if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
+			ticks = ti->pticks;
+			ti->pticks = 0;
+			resolution = ti->resolution;
+			ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
+			spin_unlock(&timer->lock);
+			if (ti->callback)
+				ti->callback(ti, resolution, ticks);
+			spin_lock(&timer->lock);
+			ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
+		}
+	}
+}
+
+/* clear pending instances from ack list */
+static void snd_timer_clear_callbacks(struct snd_timer *timer,
+				      struct list_head *head)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&timer->lock, flags);
+	while (!list_empty(head))
+		list_del_init(head->next);
+	spin_unlock_irqrestore(&timer->lock, flags);
+}
+
+/*
+ * timer work
+ *
+ */
+static void snd_timer_work(struct work_struct *work)
+{
+	struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
+	unsigned long flags;
+
+	if (timer->card && timer->card->shutdown) {
+		snd_timer_clear_callbacks(timer, &timer->sack_list_head);
+		return;
+	}
+
+	spin_lock_irqsave(&timer->lock, flags);
+	snd_timer_process_callbacks(timer, &timer->sack_list_head);
+	spin_unlock_irqrestore(&timer->lock, flags);
+}
+
+/*
+ * timer interrupt
+ *
+ * ticks_left is usually equal to timer->sticks.
+ *
+ */
+void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
+{
+	struct snd_timer_instance *ti, *ts, *tmp;
+	unsigned long resolution;
+	struct list_head *ack_list_head;
+	unsigned long flags;
+	bool use_work = false;
+
+	if (timer == NULL)
+		return;
+
+	if (timer->card && timer->card->shutdown) {
+		snd_timer_clear_callbacks(timer, &timer->ack_list_head);
+		return;
+	}
+
+	spin_lock_irqsave(&timer->lock, flags);
+
+	/* remember the current resolution */
+	resolution = snd_timer_hw_resolution(timer);
+
+	/* loop for all active instances
+	 * Here we cannot use list_for_each_entry because the active_list of a
+	 * processed instance is relinked to done_list_head before the callback
+	 * is called.
+	 */
+	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
+				 active_list) {
+		if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
+			continue;
+		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
+			continue;
+		ti->pticks += ticks_left;
+		ti->resolution = resolution;
+		if (ti->cticks < ticks_left)
+			ti->cticks = 0;
+		else
+			ti->cticks -= ticks_left;
+		if (ti->cticks) /* not expired */
+			continue;
+		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
+			ti->cticks = ti->ticks;
+		} else {
+			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
+			--timer->running;
+			list_del_init(&ti->active_list);
+		}
+		if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
+		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
+			ack_list_head = &timer->ack_list_head;
+		else
+			ack_list_head = &timer->sack_list_head;
+		if (list_empty(&ti->ack_list))
+			list_add_tail(&ti->ack_list, ack_list_head);
+		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
+			ts->pticks = ti->pticks;
+			ts->resolution = resolution;
+			if (list_empty(&ts->ack_list))
+				list_add_tail(&ts->ack_list, ack_list_head);
+		}
+	}
+	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
+		snd_timer_reschedule(timer, timer->sticks);
+	if (timer->running) {
+		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
+			timer->hw.stop(timer);
+			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
+		}
+		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
+		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
+			/* restart timer */
+			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
+			timer->hw.start(timer);
+		}
+	} else {
+		timer->hw.stop(timer);
+	}
+
+	/* now process all fast callbacks */
+	snd_timer_process_callbacks(timer, &timer->ack_list_head);
+
+	/* do we have any slow callbacks? */
+	use_work = !list_empty(&timer->sack_list_head);
+	spin_unlock_irqrestore(&timer->lock, flags);
+
+	if (use_work)
+		queue_work(system_highpri_wq, &timer->task_work);
+}
+EXPORT_SYMBOL(snd_timer_interrupt);
+
+/*
+
+ */
+
+int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
+		  struct snd_timer **rtimer)
+{
+	struct snd_timer *timer;
+	int err;
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_timer_dev_free,
+		.dev_register = snd_timer_dev_register,
+		.dev_disconnect = snd_timer_dev_disconnect,
+	};
+
+	if (snd_BUG_ON(!tid))
+		return -EINVAL;
+	if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
+	    tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
+		if (WARN_ON(!card))
+			return -EINVAL;
+	}
+	if (rtimer)
+		*rtimer = NULL;
+	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
+	if (!timer)
+		return -ENOMEM;
+	timer->tmr_class = tid->dev_class;
+	timer->card = card;
+	timer->tmr_device = tid->device;
+	timer->tmr_subdevice = tid->subdevice;
+	if (id)
+		strscpy(timer->id, id, sizeof(timer->id));
+	timer->sticks = 1;
+	INIT_LIST_HEAD(&timer->device_list);
+	INIT_LIST_HEAD(&timer->open_list_head);
+	INIT_LIST_HEAD(&timer->active_list_head);
+	INIT_LIST_HEAD(&timer->ack_list_head);
+	INIT_LIST_HEAD(&timer->sack_list_head);
+	spin_lock_init(&timer->lock);
+	INIT_WORK(&timer->task_work, snd_timer_work);
+	timer->max_instances = 1000; /* default limit per timer */
+	if (card != NULL) {
+		timer->module = card->module;
+		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
+		if (err < 0) {
+			snd_timer_free(timer);
+			return err;
+		}
+	}
+	if (rtimer)
+		*rtimer = timer;
+	return 0;
+}
+EXPORT_SYMBOL(snd_timer_new);
+
+static int snd_timer_free(struct snd_timer *timer)
+{
+	if (!timer)
+		return 0;
+
+	mutex_lock(&register_mutex);
+	if (! list_empty(&timer->open_list_head)) {
+		struct list_head *p, *n;
+		struct snd_timer_instance *ti;
+		pr_warn("ALSA: timer %p is busy?\n", timer);
+		list_for_each_safe(p, n, &timer->open_list_head) {
+			list_del_init(p);
+			ti = list_entry(p, struct snd_timer_instance, open_list);
+			ti->timer = NULL;
+		}
+	}
+	list_del(&timer->device_list);
+	mutex_unlock(&register_mutex);
+
+	if (timer->private_free)
+		timer->private_free(timer);
+	kfree(timer);
+	return 0;
+}
+
+static int snd_timer_dev_free(struct snd_device *device)
+{
+	struct snd_timer *timer = device->device_data;
+	return snd_timer_free(timer);
+}
+
+static int snd_timer_dev_register(struct snd_device *dev)
+{
+	struct snd_timer *timer = dev->device_data;
+	struct snd_timer *timer1;
+
+	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
+		return -ENXIO;
+	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
+	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
+	    	return -EINVAL;
+
+	mutex_lock(&register_mutex);
+	list_for_each_entry(timer1, &snd_timer_list, device_list) {
+		if (timer1->tmr_class > timer->tmr_class)
+			break;
+		if (timer1->tmr_class < timer->tmr_class)
+			continue;
+		if (timer1->card && timer->card) {
+			if (timer1->card->number > timer->card->number)
+				break;
+			if (timer1->card->number < timer->card->number)
+				continue;
+		}
+		if (timer1->tmr_device > timer->tmr_device)
+			break;
+		if (timer1->tmr_device < timer->tmr_device)
+			continue;
+		if (timer1->tmr_subdevice > timer->tmr_subdevice)
+			break;
+		if (timer1->tmr_subdevice < timer->tmr_subdevice)
+			continue;
+		/* conflicts.. */
+		mutex_unlock(&register_mutex);
+		return -EBUSY;
+	}
+	list_add_tail(&timer->device_list, &timer1->device_list);
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+static int snd_timer_dev_disconnect(struct snd_device *device)
+{
+	struct snd_timer *timer = device->device_data;
+	struct snd_timer_instance *ti;
+
+	mutex_lock(&register_mutex);
+	list_del_init(&timer->device_list);
+	/* wake up pending sleepers */
+	list_for_each_entry(ti, &timer->open_list_head, open_list) {
+		if (ti->disconnect)
+			ti->disconnect(ti);
+	}
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+
+void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
+{
+	unsigned long flags;
+	unsigned long resolution = 0;
+	struct snd_timer_instance *ti, *ts;
+
+	if (timer->card && timer->card->shutdown)
+		return;
+	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
+		return;
+	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
+		       event > SNDRV_TIMER_EVENT_MRESUME))
+		return;
+	spin_lock_irqsave(&timer->lock, flags);
+	if (event == SNDRV_TIMER_EVENT_MSTART ||
+	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
+	    event == SNDRV_TIMER_EVENT_MRESUME)
+		resolution = snd_timer_hw_resolution(timer);
+	list_for_each_entry(ti, &timer->active_list_head, active_list) {
+		if (ti->ccallback)
+			ti->ccallback(ti, event, tstamp, resolution);
+		list_for_each_entry(ts, &ti->slave_active_head, active_list)
+			if (ts->ccallback)
+				ts->ccallback(ts, event, tstamp, resolution);
+	}
+	spin_unlock_irqrestore(&timer->lock, flags);
+}
+EXPORT_SYMBOL(snd_timer_notify);
+
+/*
+ * exported functions for global timers
+ */
+int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
+{
+	struct snd_timer_id tid;
+
+	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
+	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	tid.card = -1;
+	tid.device = device;
+	tid.subdevice = 0;
+	return snd_timer_new(NULL, id, &tid, rtimer);
+}
+EXPORT_SYMBOL(snd_timer_global_new);
+
+int snd_timer_global_free(struct snd_timer *timer)
+{
+	return snd_timer_free(timer);
+}
+EXPORT_SYMBOL(snd_timer_global_free);
+
+int snd_timer_global_register(struct snd_timer *timer)
+{
+	struct snd_device dev;
+
+	memset(&dev, 0, sizeof(dev));
+	dev.device_data = timer;
+	return snd_timer_dev_register(&dev);
+}
+EXPORT_SYMBOL(snd_timer_global_register);
+
+/*
+ *  System timer
+ */
+
+struct snd_timer_system_private {
+	struct timer_list tlist;
+	struct snd_timer *snd_timer;
+	unsigned long last_expires;
+	unsigned long last_jiffies;
+	unsigned long correction;
+};
+
+static void snd_timer_s_function(struct timer_list *t)
+{
+	struct snd_timer_system_private *priv = from_timer(priv, t,
+								tlist);
+	struct snd_timer *timer = priv->snd_timer;
+	unsigned long jiff = jiffies;
+	if (time_after(jiff, priv->last_expires))
+		priv->correction += (long)jiff - (long)priv->last_expires;
+	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
+}
+
+static int snd_timer_s_start(struct snd_timer * timer)
+{
+	struct snd_timer_system_private *priv;
+	unsigned long njiff;
+
+	priv = (struct snd_timer_system_private *) timer->private_data;
+	njiff = (priv->last_jiffies = jiffies);
+	if (priv->correction > timer->sticks - 1) {
+		priv->correction -= timer->sticks - 1;
+		njiff++;
+	} else {
+		njiff += timer->sticks - priv->correction;
+		priv->correction = 0;
+	}
+	priv->last_expires = njiff;
+	mod_timer(&priv->tlist, njiff);
+	return 0;
+}
+
+static int snd_timer_s_stop(struct snd_timer * timer)
+{
+	struct snd_timer_system_private *priv;
+	unsigned long jiff;
+
+	priv = (struct snd_timer_system_private *) timer->private_data;
+	del_timer(&priv->tlist);
+	jiff = jiffies;
+	if (time_before(jiff, priv->last_expires))
+		timer->sticks = priv->last_expires - jiff;
+	else
+		timer->sticks = 1;
+	priv->correction = 0;
+	return 0;
+}
+
+static int snd_timer_s_close(struct snd_timer *timer)
+{
+	struct snd_timer_system_private *priv;
+
+	priv = (struct snd_timer_system_private *)timer->private_data;
+	del_timer_sync(&priv->tlist);
+	return 0;
+}
+
+static const struct snd_timer_hardware snd_timer_system =
+{
+	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
+	.resolution =	1000000000L / HZ,
+	.ticks =	10000000L,
+	.close =	snd_timer_s_close,
+	.start =	snd_timer_s_start,
+	.stop =		snd_timer_s_stop
+};
+
+static void snd_timer_free_system(struct snd_timer *timer)
+{
+	kfree(timer->private_data);
+}
+
+static int snd_timer_register_system(void)
+{
+	struct snd_timer *timer;
+	struct snd_timer_system_private *priv;
+	int err;
+
+	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
+	if (err < 0)
+		return err;
+	strcpy(timer->name, "system timer");
+	timer->hw = snd_timer_system;
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (priv == NULL) {
+		snd_timer_free(timer);
+		return -ENOMEM;
+	}
+	priv->snd_timer = timer;
+	timer_setup(&priv->tlist, snd_timer_s_function, 0);
+	timer->private_data = priv;
+	timer->private_free = snd_timer_free_system;
+	return snd_timer_global_register(timer);
+}
+
+#ifdef CONFIG_SND_PROC_FS
+/*
+ *  Info interface
+ */
+
+static void snd_timer_proc_read(struct snd_info_entry *entry,
+				struct snd_info_buffer *buffer)
+{
+	struct snd_timer *timer;
+	struct snd_timer_instance *ti;
+	unsigned long resolution;
+
+	mutex_lock(&register_mutex);
+	list_for_each_entry(timer, &snd_timer_list, device_list) {
+		if (timer->card && timer->card->shutdown)
+			continue;
+		switch (timer->tmr_class) {
+		case SNDRV_TIMER_CLASS_GLOBAL:
+			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
+			break;
+		case SNDRV_TIMER_CLASS_CARD:
+			snd_iprintf(buffer, "C%i-%i: ",
+				    timer->card->number, timer->tmr_device);
+			break;
+		case SNDRV_TIMER_CLASS_PCM:
+			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
+				    timer->tmr_device, timer->tmr_subdevice);
+			break;
+		default:
+			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
+				    timer->card ? timer->card->number : -1,
+				    timer->tmr_device, timer->tmr_subdevice);
+		}
+		snd_iprintf(buffer, "%s :", timer->name);
+		spin_lock_irq(&timer->lock);
+		resolution = snd_timer_hw_resolution(timer);
+		spin_unlock_irq(&timer->lock);
+		if (resolution)
+			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
+				    resolution / 1000,
+				    resolution % 1000,
+				    timer->hw.ticks);
+		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			snd_iprintf(buffer, " SLAVE");
+		snd_iprintf(buffer, "\n");
+		list_for_each_entry(ti, &timer->open_list_head, open_list)
+			snd_iprintf(buffer, "  Client %s : %s\n",
+				    ti->owner ? ti->owner : "unknown",
+				    (ti->flags & (SNDRV_TIMER_IFLG_START |
+						  SNDRV_TIMER_IFLG_RUNNING))
+				    ? "running" : "stopped");
+	}
+	mutex_unlock(&register_mutex);
+}
+
+static struct snd_info_entry *snd_timer_proc_entry;
+
+static void __init snd_timer_proc_init(void)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
+	if (entry != NULL) {
+		entry->c.text.read = snd_timer_proc_read;
+		if (snd_info_register(entry) < 0) {
+			snd_info_free_entry(entry);
+			entry = NULL;
+		}
+	}
+	snd_timer_proc_entry = entry;
+}
+
+static void __exit snd_timer_proc_done(void)
+{
+	snd_info_free_entry(snd_timer_proc_entry);
+}
+#else /* !CONFIG_SND_PROC_FS */
+#define snd_timer_proc_init()
+#define snd_timer_proc_done()
+#endif
+
+/*
+ *  USER SPACE interface
+ */
+
+static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
+				     unsigned long resolution,
+				     unsigned long ticks)
+{
+	struct snd_timer_user *tu = timeri->callback_data;
+	struct snd_timer_read *r;
+	int prev;
+
+	spin_lock(&tu->qlock);
+	if (tu->qused > 0) {
+		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
+		r = &tu->queue[prev];
+		if (r->resolution == resolution) {
+			r->ticks += ticks;
+			goto __wake;
+		}
+	}
+	if (tu->qused >= tu->queue_size) {
+		tu->overrun++;
+	} else {
+		r = &tu->queue[tu->qtail++];
+		tu->qtail %= tu->queue_size;
+		r->resolution = resolution;
+		r->ticks = ticks;
+		tu->qused++;
+	}
+      __wake:
+	spin_unlock(&tu->qlock);
+	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
+	wake_up(&tu->qchange_sleep);
+}
+
+static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
+					    struct snd_timer_tread64 *tread)
+{
+	if (tu->qused >= tu->queue_size) {
+		tu->overrun++;
+	} else {
+		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
+		tu->qtail %= tu->queue_size;
+		tu->qused++;
+	}
+}
+
+static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
+				     int event,
+				     struct timespec64 *tstamp,
+				     unsigned long resolution)
+{
+	struct snd_timer_user *tu = timeri->callback_data;
+	struct snd_timer_tread64 r1;
+	unsigned long flags;
+
+	if (event >= SNDRV_TIMER_EVENT_START &&
+	    event <= SNDRV_TIMER_EVENT_PAUSE)
+		tu->tstamp = *tstamp;
+	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
+		return;
+	memset(&r1, 0, sizeof(r1));
+	r1.event = event;
+	r1.tstamp_sec = tstamp->tv_sec;
+	r1.tstamp_nsec = tstamp->tv_nsec;
+	r1.val = resolution;
+	spin_lock_irqsave(&tu->qlock, flags);
+	snd_timer_user_append_to_tqueue(tu, &r1);
+	spin_unlock_irqrestore(&tu->qlock, flags);
+	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
+	wake_up(&tu->qchange_sleep);
+}
+
+static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
+{
+	struct snd_timer_user *tu = timeri->callback_data;
+
+	tu->disconnected = true;
+	wake_up(&tu->qchange_sleep);
+}
+
+static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
+				      unsigned long resolution,
+				      unsigned long ticks)
+{
+	struct snd_timer_user *tu = timeri->callback_data;
+	struct snd_timer_tread64 *r, r1;
+	struct timespec64 tstamp;
+	int prev, append = 0;
+
+	memset(&r1, 0, sizeof(r1));
+	memset(&tstamp, 0, sizeof(tstamp));
+	spin_lock(&tu->qlock);
+	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
+			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
+		spin_unlock(&tu->qlock);
+		return;
+	}
+	if (tu->last_resolution != resolution || ticks > 0) {
+		if (timer_tstamp_monotonic)
+			ktime_get_ts64(&tstamp);
+		else
+			ktime_get_real_ts64(&tstamp);
+	}
+	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
+	    tu->last_resolution != resolution) {
+		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
+		r1.tstamp_sec = tstamp.tv_sec;
+		r1.tstamp_nsec = tstamp.tv_nsec;
+		r1.val = resolution;
+		snd_timer_user_append_to_tqueue(tu, &r1);
+		tu->last_resolution = resolution;
+		append++;
+	}
+	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
+		goto __wake;
+	if (ticks == 0)
+		goto __wake;
+	if (tu->qused > 0) {
+		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
+		r = &tu->tqueue[prev];
+		if (r->event == SNDRV_TIMER_EVENT_TICK) {
+			r->tstamp_sec = tstamp.tv_sec;
+			r->tstamp_nsec = tstamp.tv_nsec;
+			r->val += ticks;
+			append++;
+			goto __wake;
+		}
+	}
+	r1.event = SNDRV_TIMER_EVENT_TICK;
+	r1.tstamp_sec = tstamp.tv_sec;
+	r1.tstamp_nsec = tstamp.tv_nsec;
+	r1.val = ticks;
+	snd_timer_user_append_to_tqueue(tu, &r1);
+	append++;
+      __wake:
+	spin_unlock(&tu->qlock);
+	if (append == 0)
+		return;
+	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
+	wake_up(&tu->qchange_sleep);
+}
+
+static int realloc_user_queue(struct snd_timer_user *tu, int size)
+{
+	struct snd_timer_read *queue = NULL;
+	struct snd_timer_tread64 *tqueue = NULL;
+
+	if (tu->tread) {
+		tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
+		if (!tqueue)
+			return -ENOMEM;
+	} else {
+		queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
+		if (!queue)
+			return -ENOMEM;
+	}
+
+	spin_lock_irq(&tu->qlock);
+	kfree(tu->queue);
+	kfree(tu->tqueue);
+	tu->queue_size = size;
+	tu->queue = queue;
+	tu->tqueue = tqueue;
+	tu->qhead = tu->qtail = tu->qused = 0;
+	spin_unlock_irq(&tu->qlock);
+
+	return 0;
+}
+
+static int snd_timer_user_open(struct inode *inode, struct file *file)
+{
+	struct snd_timer_user *tu;
+	int err;
+
+	err = stream_open(inode, file);
+	if (err < 0)
+		return err;
+
+	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
+	if (tu == NULL)
+		return -ENOMEM;
+	spin_lock_init(&tu->qlock);
+	init_waitqueue_head(&tu->qchange_sleep);
+	mutex_init(&tu->ioctl_lock);
+	tu->ticks = 1;
+	if (realloc_user_queue(tu, 128) < 0) {
+		kfree(tu);
+		return -ENOMEM;
+	}
+	file->private_data = tu;
+	return 0;
+}
+
+static int snd_timer_user_release(struct inode *inode, struct file *file)
+{
+	struct snd_timer_user *tu;
+
+	if (file->private_data) {
+		tu = file->private_data;
+		file->private_data = NULL;
+		mutex_lock(&tu->ioctl_lock);
+		if (tu->timeri) {
+			snd_timer_close(tu->timeri);
+			snd_timer_instance_free(tu->timeri);
+		}
+		mutex_unlock(&tu->ioctl_lock);
+		snd_fasync_free(tu->fasync);
+		kfree(tu->queue);
+		kfree(tu->tqueue);
+		kfree(tu);
+	}
+	return 0;
+}
+
+static void snd_timer_user_zero_id(struct snd_timer_id *id)
+{
+	id->dev_class = SNDRV_TIMER_CLASS_NONE;
+	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	id->card = -1;
+	id->device = -1;
+	id->subdevice = -1;
+}
+
+static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
+{
+	id->dev_class = timer->tmr_class;
+	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	id->card = timer->card ? timer->card->number : -1;
+	id->device = timer->tmr_device;
+	id->subdevice = timer->tmr_subdevice;
+}
+
+static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
+{
+	struct snd_timer_id id;
+	struct snd_timer *timer;
+	struct list_head *p;
+
+	if (copy_from_user(&id, _tid, sizeof(id)))
+		return -EFAULT;
+	mutex_lock(&register_mutex);
+	if (id.dev_class < 0) {		/* first item */
+		if (list_empty(&snd_timer_list))
+			snd_timer_user_zero_id(&id);
+		else {
+			timer = list_entry(snd_timer_list.next,
+					   struct snd_timer, device_list);
+			snd_timer_user_copy_id(&id, timer);
+		}
+	} else {
+		switch (id.dev_class) {
+		case SNDRV_TIMER_CLASS_GLOBAL:
+			id.device = id.device < 0 ? 0 : id.device + 1;
+			list_for_each(p, &snd_timer_list) {
+				timer = list_entry(p, struct snd_timer, device_list);
+				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_device >= id.device) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+			}
+			if (p == &snd_timer_list)
+				snd_timer_user_zero_id(&id);
+			break;
+		case SNDRV_TIMER_CLASS_CARD:
+		case SNDRV_TIMER_CLASS_PCM:
+			if (id.card < 0) {
+				id.card = 0;
+			} else {
+				if (id.device < 0) {
+					id.device = 0;
+				} else {
+					if (id.subdevice < 0)
+						id.subdevice = 0;
+					else if (id.subdevice < INT_MAX)
+						id.subdevice++;
+				}
+			}
+			list_for_each(p, &snd_timer_list) {
+				timer = list_entry(p, struct snd_timer, device_list);
+				if (timer->tmr_class > id.dev_class) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_class < id.dev_class)
+					continue;
+				if (timer->card->number > id.card) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->card->number < id.card)
+					continue;
+				if (timer->tmr_device > id.device) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_device < id.device)
+					continue;
+				if (timer->tmr_subdevice > id.subdevice) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_subdevice < id.subdevice)
+					continue;
+				snd_timer_user_copy_id(&id, timer);
+				break;
+			}
+			if (p == &snd_timer_list)
+				snd_timer_user_zero_id(&id);
+			break;
+		default:
+			snd_timer_user_zero_id(&id);
+		}
+	}
+	mutex_unlock(&register_mutex);
+	if (copy_to_user(_tid, &id, sizeof(*_tid)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_timer_user_ginfo(struct file *file,
+				struct snd_timer_ginfo __user *_ginfo)
+{
+	struct snd_timer_ginfo *ginfo;
+	struct snd_timer_id tid;
+	struct snd_timer *t;
+	struct list_head *p;
+	int err = 0;
+
+	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
+	if (IS_ERR(ginfo))
+		return PTR_ERR(ginfo);
+
+	tid = ginfo->tid;
+	memset(ginfo, 0, sizeof(*ginfo));
+	ginfo->tid = tid;
+	mutex_lock(&register_mutex);
+	t = snd_timer_find(&tid);
+	if (t != NULL) {
+		ginfo->card = t->card ? t->card->number : -1;
+		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
+		strscpy(ginfo->id, t->id, sizeof(ginfo->id));
+		strscpy(ginfo->name, t->name, sizeof(ginfo->name));
+		spin_lock_irq(&t->lock);
+		ginfo->resolution = snd_timer_hw_resolution(t);
+		spin_unlock_irq(&t->lock);
+		if (t->hw.resolution_min > 0) {
+			ginfo->resolution_min = t->hw.resolution_min;
+			ginfo->resolution_max = t->hw.resolution_max;
+		}
+		list_for_each(p, &t->open_list_head) {
+			ginfo->clients++;
+		}
+	} else {
+		err = -ENODEV;
+	}
+	mutex_unlock(&register_mutex);
+	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
+		err = -EFAULT;
+	kfree(ginfo);
+	return err;
+}
+
+static int timer_set_gparams(struct snd_timer_gparams *gparams)
+{
+	struct snd_timer *t;
+	int err;
+
+	mutex_lock(&register_mutex);
+	t = snd_timer_find(&gparams->tid);
+	if (!t) {
+		err = -ENODEV;
+		goto _error;
+	}
+	if (!list_empty(&t->open_list_head)) {
+		err = -EBUSY;
+		goto _error;
+	}
+	if (!t->hw.set_period) {
+		err = -ENOSYS;
+		goto _error;
+	}
+	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
+_error:
+	mutex_unlock(&register_mutex);
+	return err;
+}
+
+static int snd_timer_user_gparams(struct file *file,
+				  struct snd_timer_gparams __user *_gparams)
+{
+	struct snd_timer_gparams gparams;
+
+	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
+		return -EFAULT;
+	return timer_set_gparams(&gparams);
+}
+
+static int snd_timer_user_gstatus(struct file *file,
+				  struct snd_timer_gstatus __user *_gstatus)
+{
+	struct snd_timer_gstatus gstatus;
+	struct snd_timer_id tid;
+	struct snd_timer *t;
+	int err = 0;
+
+	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
+		return -EFAULT;
+	tid = gstatus.tid;
+	memset(&gstatus, 0, sizeof(gstatus));
+	gstatus.tid = tid;
+	mutex_lock(&register_mutex);
+	t = snd_timer_find(&tid);
+	if (t != NULL) {
+		spin_lock_irq(&t->lock);
+		gstatus.resolution = snd_timer_hw_resolution(t);
+		if (t->hw.precise_resolution) {
+			t->hw.precise_resolution(t, &gstatus.resolution_num,
+						 &gstatus.resolution_den);
+		} else {
+			gstatus.resolution_num = gstatus.resolution;
+			gstatus.resolution_den = 1000000000uL;
+		}
+		spin_unlock_irq(&t->lock);
+	} else {
+		err = -ENODEV;
+	}
+	mutex_unlock(&register_mutex);
+	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
+		err = -EFAULT;
+	return err;
+}
+
+static int snd_timer_user_tselect(struct file *file,
+				  struct snd_timer_select __user *_tselect)
+{
+	struct snd_timer_user *tu;
+	struct snd_timer_select tselect;
+	char str[32];
+	int err = 0;
+
+	tu = file->private_data;
+	if (tu->timeri) {
+		snd_timer_close(tu->timeri);
+		snd_timer_instance_free(tu->timeri);
+		tu->timeri = NULL;
+	}
+	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
+		err = -EFAULT;
+		goto __err;
+	}
+	sprintf(str, "application %i", current->pid);
+	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
+		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
+	tu->timeri = snd_timer_instance_new(str);
+	if (!tu->timeri) {
+		err = -ENOMEM;
+		goto __err;
+	}
+
+	tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
+	tu->timeri->callback = tu->tread
+			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
+	tu->timeri->ccallback = snd_timer_user_ccallback;
+	tu->timeri->callback_data = (void *)tu;
+	tu->timeri->disconnect = snd_timer_user_disconnect;
+
+	err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
+	if (err < 0) {
+		snd_timer_instance_free(tu->timeri);
+		tu->timeri = NULL;
+	}
+
+      __err:
+	return err;
+}
+
+static int snd_timer_user_info(struct file *file,
+			       struct snd_timer_info __user *_info)
+{
+	struct snd_timer_user *tu;
+	struct snd_timer_info *info;
+	struct snd_timer *t;
+	int err = 0;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	t = tu->timeri->timer;
+	if (!t)
+		return -EBADFD;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (! info)
+		return -ENOMEM;
+	info->card = t->card ? t->card->number : -1;
+	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+		info->flags |= SNDRV_TIMER_FLG_SLAVE;
+	strscpy(info->id, t->id, sizeof(info->id));
+	strscpy(info->name, t->name, sizeof(info->name));
+	spin_lock_irq(&t->lock);
+	info->resolution = snd_timer_hw_resolution(t);
+	spin_unlock_irq(&t->lock);
+	if (copy_to_user(_info, info, sizeof(*_info)))
+		err = -EFAULT;
+	kfree(info);
+	return err;
+}
+
+static int snd_timer_user_params(struct file *file,
+				 struct snd_timer_params __user *_params)
+{
+	struct snd_timer_user *tu;
+	struct snd_timer_params params;
+	struct snd_timer *t;
+	int err;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	t = tu->timeri->timer;
+	if (!t)
+		return -EBADFD;
+	if (copy_from_user(&params, _params, sizeof(params)))
+		return -EFAULT;
+	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
+		u64 resolution;
+
+		if (params.ticks < 1) {
+			err = -EINVAL;
+			goto _end;
+		}
+
+		/* Don't allow resolution less than 1ms */
+		resolution = snd_timer_resolution(tu->timeri);
+		resolution *= params.ticks;
+		if (resolution < 1000000) {
+			err = -EINVAL;
+			goto _end;
+		}
+	}
+	if (params.queue_size > 0 &&
+	    (params.queue_size < 32 || params.queue_size > 1024)) {
+		err = -EINVAL;
+		goto _end;
+	}
+	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
+			      (1<<SNDRV_TIMER_EVENT_TICK)|
+			      (1<<SNDRV_TIMER_EVENT_START)|
+			      (1<<SNDRV_TIMER_EVENT_STOP)|
+			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
+			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
+			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
+			      (1<<SNDRV_TIMER_EVENT_RESUME)|
+			      (1<<SNDRV_TIMER_EVENT_MSTART)|
+			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
+			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
+			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
+			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
+			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
+		err = -EINVAL;
+		goto _end;
+	}
+	snd_timer_stop(tu->timeri);
+	spin_lock_irq(&t->lock);
+	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
+			       SNDRV_TIMER_IFLG_EXCLUSIVE|
+			       SNDRV_TIMER_IFLG_EARLY_EVENT);
+	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
+		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
+	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
+		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
+	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
+		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
+	spin_unlock_irq(&t->lock);
+	if (params.queue_size > 0 &&
+	    (unsigned int)tu->queue_size != params.queue_size) {
+		err = realloc_user_queue(tu, params.queue_size);
+		if (err < 0)
+			goto _end;
+	}
+	spin_lock_irq(&tu->qlock);
+	tu->qhead = tu->qtail = tu->qused = 0;
+	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
+		if (tu->tread) {
+			struct snd_timer_tread64 tread;
+			memset(&tread, 0, sizeof(tread));
+			tread.event = SNDRV_TIMER_EVENT_EARLY;
+			tread.tstamp_sec = 0;
+			tread.tstamp_nsec = 0;
+			tread.val = 0;
+			snd_timer_user_append_to_tqueue(tu, &tread);
+		} else {
+			struct snd_timer_read *r = &tu->queue[0];
+			r->resolution = 0;
+			r->ticks = 0;
+			tu->qused++;
+			tu->qtail++;
+		}
+	}
+	tu->filter = params.filter;
+	tu->ticks = params.ticks;
+	spin_unlock_irq(&tu->qlock);
+	err = 0;
+ _end:
+	if (copy_to_user(_params, &params, sizeof(params)))
+		return -EFAULT;
+	return err;
+}
+
+static int snd_timer_user_status32(struct file *file,
+				   struct snd_timer_status32 __user *_status)
+ {
+	struct snd_timer_user *tu;
+	struct snd_timer_status32 status;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	memset(&status, 0, sizeof(status));
+	status.tstamp_sec = tu->tstamp.tv_sec;
+	status.tstamp_nsec = tu->tstamp.tv_nsec;
+	status.resolution = snd_timer_resolution(tu->timeri);
+	status.lost = tu->timeri->lost;
+	status.overrun = tu->overrun;
+	spin_lock_irq(&tu->qlock);
+	status.queue = tu->qused;
+	spin_unlock_irq(&tu->qlock);
+	if (copy_to_user(_status, &status, sizeof(status)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_timer_user_status64(struct file *file,
+				   struct snd_timer_status64 __user *_status)
+{
+	struct snd_timer_user *tu;
+	struct snd_timer_status64 status;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	memset(&status, 0, sizeof(status));
+	status.tstamp_sec = tu->tstamp.tv_sec;
+	status.tstamp_nsec = tu->tstamp.tv_nsec;
+	status.resolution = snd_timer_resolution(tu->timeri);
+	status.lost = tu->timeri->lost;
+	status.overrun = tu->overrun;
+	spin_lock_irq(&tu->qlock);
+	status.queue = tu->qused;
+	spin_unlock_irq(&tu->qlock);
+	if (copy_to_user(_status, &status, sizeof(status)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_timer_user_start(struct file *file)
+{
+	int err;
+	struct snd_timer_user *tu;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	snd_timer_stop(tu->timeri);
+	tu->timeri->lost = 0;
+	tu->last_resolution = 0;
+	err = snd_timer_start(tu->timeri, tu->ticks);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_timer_user_stop(struct file *file)
+{
+	int err;
+	struct snd_timer_user *tu;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	err = snd_timer_stop(tu->timeri);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_timer_user_continue(struct file *file)
+{
+	int err;
+	struct snd_timer_user *tu;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	/* start timer instead of continue if it's not used before */
+	if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
+		return snd_timer_user_start(file);
+	tu->timeri->lost = 0;
+	err = snd_timer_continue(tu->timeri);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_timer_user_pause(struct file *file)
+{
+	int err;
+	struct snd_timer_user *tu;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	err = snd_timer_pause(tu->timeri);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
+				unsigned int cmd, bool compat)
+{
+	int __user *p = argp;
+	int xarg, old_tread;
+
+	if (tu->timeri)	/* too late */
+		return -EBUSY;
+	if (get_user(xarg, p))
+		return -EFAULT;
+
+	old_tread = tu->tread;
+
+	if (!xarg)
+		tu->tread = TREAD_FORMAT_NONE;
+	else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
+		 (IS_ENABLED(CONFIG_64BIT) && !compat))
+		tu->tread = TREAD_FORMAT_TIME64;
+	else
+		tu->tread = TREAD_FORMAT_TIME32;
+
+	if (tu->tread != old_tread &&
+	    realloc_user_queue(tu, tu->queue_size) < 0) {
+		tu->tread = old_tread;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+enum {
+	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
+	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
+	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
+	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
+};
+
+static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
+				 unsigned long arg, bool compat)
+{
+	struct snd_timer_user *tu;
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+
+	tu = file->private_data;
+	switch (cmd) {
+	case SNDRV_TIMER_IOCTL_PVERSION:
+		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
+	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
+		return snd_timer_user_next_device(argp);
+	case SNDRV_TIMER_IOCTL_TREAD_OLD:
+	case SNDRV_TIMER_IOCTL_TREAD64:
+		return snd_timer_user_tread(argp, tu, cmd, compat);
+	case SNDRV_TIMER_IOCTL_GINFO:
+		return snd_timer_user_ginfo(file, argp);
+	case SNDRV_TIMER_IOCTL_GPARAMS:
+		return snd_timer_user_gparams(file, argp);
+	case SNDRV_TIMER_IOCTL_GSTATUS:
+		return snd_timer_user_gstatus(file, argp);
+	case SNDRV_TIMER_IOCTL_SELECT:
+		return snd_timer_user_tselect(file, argp);
+	case SNDRV_TIMER_IOCTL_INFO:
+		return snd_timer_user_info(file, argp);
+	case SNDRV_TIMER_IOCTL_PARAMS:
+		return snd_timer_user_params(file, argp);
+	case SNDRV_TIMER_IOCTL_STATUS32:
+		return snd_timer_user_status32(file, argp);
+	case SNDRV_TIMER_IOCTL_STATUS64:
+		return snd_timer_user_status64(file, argp);
+	case SNDRV_TIMER_IOCTL_START:
+	case SNDRV_TIMER_IOCTL_START_OLD:
+		return snd_timer_user_start(file);
+	case SNDRV_TIMER_IOCTL_STOP:
+	case SNDRV_TIMER_IOCTL_STOP_OLD:
+		return snd_timer_user_stop(file);
+	case SNDRV_TIMER_IOCTL_CONTINUE:
+	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
+		return snd_timer_user_continue(file);
+	case SNDRV_TIMER_IOCTL_PAUSE:
+	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
+		return snd_timer_user_pause(file);
+	}
+	return -ENOTTY;
+}
+
+static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
+				 unsigned long arg)
+{
+	struct snd_timer_user *tu = file->private_data;
+	long ret;
+
+	mutex_lock(&tu->ioctl_lock);
+	ret = __snd_timer_user_ioctl(file, cmd, arg, false);
+	mutex_unlock(&tu->ioctl_lock);
+	return ret;
+}
+
+static int snd_timer_user_fasync(int fd, struct file * file, int on)
+{
+	struct snd_timer_user *tu;
+
+	tu = file->private_data;
+	return snd_fasync_helper(fd, file, on, &tu->fasync);
+}
+
+static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
+				   size_t count, loff_t *offset)
+{
+	struct snd_timer_tread64 *tread;
+	struct snd_timer_tread32 tread32;
+	struct snd_timer_user *tu;
+	long result = 0, unit;
+	int qhead;
+	int err = 0;
+
+	tu = file->private_data;
+	switch (tu->tread) {
+	case TREAD_FORMAT_TIME64:
+		unit = sizeof(struct snd_timer_tread64);
+		break;
+	case TREAD_FORMAT_TIME32:
+		unit = sizeof(struct snd_timer_tread32);
+		break;
+	case TREAD_FORMAT_NONE:
+		unit = sizeof(struct snd_timer_read);
+		break;
+	default:
+		WARN_ONCE(1, "Corrupt snd_timer_user\n");
+		return -ENOTSUPP;
+	}
+
+	mutex_lock(&tu->ioctl_lock);
+	spin_lock_irq(&tu->qlock);
+	while ((long)count - result >= unit) {
+		while (!tu->qused) {
+			wait_queue_entry_t wait;
+
+			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
+				err = -EAGAIN;
+				goto _error;
+			}
+
+			set_current_state(TASK_INTERRUPTIBLE);
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&tu->qchange_sleep, &wait);
+
+			spin_unlock_irq(&tu->qlock);
+			mutex_unlock(&tu->ioctl_lock);
+			schedule();
+			mutex_lock(&tu->ioctl_lock);
+			spin_lock_irq(&tu->qlock);
+
+			remove_wait_queue(&tu->qchange_sleep, &wait);
+
+			if (tu->disconnected) {
+				err = -ENODEV;
+				goto _error;
+			}
+			if (signal_pending(current)) {
+				err = -ERESTARTSYS;
+				goto _error;
+			}
+		}
+
+		qhead = tu->qhead++;
+		tu->qhead %= tu->queue_size;
+		tu->qused--;
+		spin_unlock_irq(&tu->qlock);
+
+		tread = &tu->tqueue[qhead];
+
+		switch (tu->tread) {
+		case TREAD_FORMAT_TIME64:
+			if (copy_to_user(buffer, tread,
+					 sizeof(struct snd_timer_tread64)))
+				err = -EFAULT;
+			break;
+		case TREAD_FORMAT_TIME32:
+			memset(&tread32, 0, sizeof(tread32));
+			tread32 = (struct snd_timer_tread32) {
+				.event = tread->event,
+				.tstamp_sec = tread->tstamp_sec,
+				.tstamp_nsec = tread->tstamp_nsec,
+				.val = tread->val,
+			};
+
+			if (copy_to_user(buffer, &tread32, sizeof(tread32)))
+				err = -EFAULT;
+			break;
+		case TREAD_FORMAT_NONE:
+			if (copy_to_user(buffer, &tu->queue[qhead],
+					 sizeof(struct snd_timer_read)))
+				err = -EFAULT;
+			break;
+		default:
+			err = -ENOTSUPP;
+			break;
+		}
+
+		spin_lock_irq(&tu->qlock);
+		if (err < 0)
+			goto _error;
+		result += unit;
+		buffer += unit;
+	}
+ _error:
+	spin_unlock_irq(&tu->qlock);
+	mutex_unlock(&tu->ioctl_lock);
+	return result > 0 ? result : err;
+}
+
+static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
+{
+        __poll_t mask;
+        struct snd_timer_user *tu;
+
+        tu = file->private_data;
+
+        poll_wait(file, &tu->qchange_sleep, wait);
+
+	mask = 0;
+	spin_lock_irq(&tu->qlock);
+	if (tu->qused)
+		mask |= EPOLLIN | EPOLLRDNORM;
+	if (tu->disconnected)
+		mask |= EPOLLERR;
+	spin_unlock_irq(&tu->qlock);
+
+	return mask;
+}
+
+#ifdef CONFIG_COMPAT
+#include "timer_compat.c"
+#else
+#define snd_timer_user_ioctl_compat	NULL
+#endif
+
+static const struct file_operations snd_timer_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.read =		snd_timer_user_read,
+	.open =		snd_timer_user_open,
+	.release =	snd_timer_user_release,
+	.llseek =	no_llseek,
+	.poll =		snd_timer_user_poll,
+	.unlocked_ioctl =	snd_timer_user_ioctl,
+	.compat_ioctl =	snd_timer_user_ioctl_compat,
+	.fasync = 	snd_timer_user_fasync,
+};
+
+/* unregister the system timer */
+static void snd_timer_free_all(void)
+{
+	struct snd_timer *timer, *n;
+
+	list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
+		snd_timer_free(timer);
+}
+
+static struct device *timer_dev;
+
+/*
+ *  ENTRY functions
+ */
+
+static int __init alsa_timer_init(void)
+{
+	int err;
+
+	err = snd_device_alloc(&timer_dev, NULL);
+	if (err < 0)
+		return err;
+	dev_set_name(timer_dev, "timer");
+
+#ifdef SNDRV_OSS_INFO_DEV_TIMERS
+	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
+			      "system timer");
+#endif
+
+	err = snd_timer_register_system();
+	if (err < 0) {
+		pr_err("ALSA: unable to register system timer (%i)\n", err);
+		goto put_timer;
+	}
+
+	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
+				  &snd_timer_f_ops, NULL, timer_dev);
+	if (err < 0) {
+		pr_err("ALSA: unable to register timer device (%i)\n", err);
+		snd_timer_free_all();
+		goto put_timer;
+	}
+
+	snd_timer_proc_init();
+	return 0;
+
+put_timer:
+	put_device(timer_dev);
+	return err;
+}
+
+static void __exit alsa_timer_exit(void)
+{
+	snd_unregister_device(timer_dev);
+	snd_timer_free_all();
+	put_device(timer_dev);
+	snd_timer_proc_done();
+#ifdef SNDRV_OSS_INFO_DEV_TIMERS
+	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
+#endif
+}
+
+module_init(alsa_timer_init)
+module_exit(alsa_timer_exit)
diff --git a/sound/core/timer_compat.c b/sound/core/timer_compat.c
new file mode 100644
index 0000000000..ee973b7b80
--- /dev/null
+++ b/sound/core/timer_compat.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   32bit -> 64bit ioctl wrapper for timer API
+ *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ */
+
+/* This file included from timer.c */
+
+#include <linux/compat.h>
+
+/*
+ * ILP32/LP64 has different size for 'long' type. Additionally, the size
+ * of storage alignment differs depending on architectures. Here, '__packed'
+ * qualifier is used so that the size of this structure is multiple of 4 and
+ * it fits to any architectures with 32 bit storage alignment.
+ */
+struct snd_timer_gparams32 {
+	struct snd_timer_id tid;
+	u32 period_num;
+	u32 period_den;
+	unsigned char reserved[32];
+} __packed;
+
+struct snd_timer_info32 {
+	u32 flags;
+	s32 card;
+	unsigned char id[64];
+	unsigned char name[80];
+	u32 reserved0;
+	u32 resolution;
+	unsigned char reserved[64];
+};
+
+static int snd_timer_user_gparams_compat(struct file *file,
+					struct snd_timer_gparams32 __user *user)
+{
+	struct snd_timer_gparams gparams;
+
+	if (copy_from_user(&gparams.tid, &user->tid, sizeof(gparams.tid)) ||
+	    get_user(gparams.period_num, &user->period_num) ||
+	    get_user(gparams.period_den, &user->period_den))
+		return -EFAULT;
+
+	return timer_set_gparams(&gparams);
+}
+
+static int snd_timer_user_info_compat(struct file *file,
+				      struct snd_timer_info32 __user *_info)
+{
+	struct snd_timer_user *tu;
+	struct snd_timer_info32 info;
+	struct snd_timer *t;
+
+	tu = file->private_data;
+	if (!tu->timeri)
+		return -EBADFD;
+	t = tu->timeri->timer;
+	if (!t)
+		return -EBADFD;
+	memset(&info, 0, sizeof(info));
+	info.card = t->card ? t->card->number : -1;
+	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+		info.flags |= SNDRV_TIMER_FLG_SLAVE;
+	strscpy(info.id, t->id, sizeof(info.id));
+	strscpy(info.name, t->name, sizeof(info.name));
+	info.resolution = t->hw.resolution;
+	if (copy_to_user(_info, &info, sizeof(*_info)))
+		return -EFAULT;
+	return 0;
+}
+
+enum {
+	SNDRV_TIMER_IOCTL_GPARAMS32 = _IOW('T', 0x04, struct snd_timer_gparams32),
+	SNDRV_TIMER_IOCTL_INFO32 = _IOR('T', 0x11, struct snd_timer_info32),
+	SNDRV_TIMER_IOCTL_STATUS_COMPAT32 = _IOW('T', 0x14, struct snd_timer_status32),
+	SNDRV_TIMER_IOCTL_STATUS_COMPAT64 = _IOW('T', 0x14, struct snd_timer_status64),
+};
+
+static long __snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd,
+					  unsigned long arg)
+{
+	void __user *argp = compat_ptr(arg);
+
+	switch (cmd) {
+	case SNDRV_TIMER_IOCTL_PVERSION:
+	case SNDRV_TIMER_IOCTL_TREAD_OLD:
+	case SNDRV_TIMER_IOCTL_TREAD64:
+	case SNDRV_TIMER_IOCTL_GINFO:
+	case SNDRV_TIMER_IOCTL_GSTATUS:
+	case SNDRV_TIMER_IOCTL_SELECT:
+	case SNDRV_TIMER_IOCTL_PARAMS:
+	case SNDRV_TIMER_IOCTL_START:
+	case SNDRV_TIMER_IOCTL_START_OLD:
+	case SNDRV_TIMER_IOCTL_STOP:
+	case SNDRV_TIMER_IOCTL_STOP_OLD:
+	case SNDRV_TIMER_IOCTL_CONTINUE:
+	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
+	case SNDRV_TIMER_IOCTL_PAUSE:
+	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
+	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
+		return __snd_timer_user_ioctl(file, cmd, (unsigned long)argp, true);
+	case SNDRV_TIMER_IOCTL_GPARAMS32:
+		return snd_timer_user_gparams_compat(file, argp);
+	case SNDRV_TIMER_IOCTL_INFO32:
+		return snd_timer_user_info_compat(file, argp);
+	case SNDRV_TIMER_IOCTL_STATUS_COMPAT32:
+		return snd_timer_user_status32(file, argp);
+	case SNDRV_TIMER_IOCTL_STATUS_COMPAT64:
+		return snd_timer_user_status64(file, argp);
+	}
+	return -ENOIOCTLCMD;
+}
+
+static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd,
+					unsigned long arg)
+{
+	struct snd_timer_user *tu = file->private_data;
+	long ret;
+
+	mutex_lock(&tu->ioctl_lock);
+	ret = __snd_timer_user_ioctl_compat(file, cmd, arg);
+	mutex_unlock(&tu->ioctl_lock);
+	return ret;
+}
diff --git a/sound/core/ump.c b/sound/core/ump.c
new file mode 100644
index 0000000000..3bef1944e9
--- /dev/null
+++ b/sound/core/ump.c
@@ -0,0 +1,1212 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Universal MIDI Packet (UMP) support
+ */
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <sound/core.h>
+#include <sound/rawmidi.h>
+#include <sound/ump.h>
+#include <sound/ump_convert.h>
+
+#define ump_err(ump, fmt, args...)	dev_err((ump)->core.dev, fmt, ##args)
+#define ump_warn(ump, fmt, args...)	dev_warn((ump)->core.dev, fmt, ##args)
+#define ump_info(ump, fmt, args...)	dev_info((ump)->core.dev, fmt, ##args)
+#define ump_dbg(ump, fmt, args...)	dev_dbg((ump)->core.dev, fmt, ##args)
+
+static int snd_ump_dev_register(struct snd_rawmidi *rmidi);
+static int snd_ump_dev_unregister(struct snd_rawmidi *rmidi);
+static long snd_ump_ioctl(struct snd_rawmidi *rmidi, unsigned int cmd,
+			  void __user *argp);
+static void snd_ump_proc_read(struct snd_info_entry *entry,
+			      struct snd_info_buffer *buffer);
+static int snd_ump_rawmidi_open(struct snd_rawmidi_substream *substream);
+static int snd_ump_rawmidi_close(struct snd_rawmidi_substream *substream);
+static void snd_ump_rawmidi_trigger(struct snd_rawmidi_substream *substream,
+				    int up);
+static void snd_ump_rawmidi_drain(struct snd_rawmidi_substream *substream);
+
+static void ump_handle_stream_msg(struct snd_ump_endpoint *ump,
+				  const u32 *buf, int size);
+#if IS_ENABLED(CONFIG_SND_UMP_LEGACY_RAWMIDI)
+static int process_legacy_output(struct snd_ump_endpoint *ump,
+				 u32 *buffer, int count);
+static void process_legacy_input(struct snd_ump_endpoint *ump, const u32 *src,
+				 int words);
+#else
+static inline int process_legacy_output(struct snd_ump_endpoint *ump,
+					u32 *buffer, int count)
+{
+	return 0;
+}
+static inline void process_legacy_input(struct snd_ump_endpoint *ump,
+					const u32 *src, int words)
+{
+}
+#endif
+
+static const struct snd_rawmidi_global_ops snd_ump_rawmidi_ops = {
+	.dev_register = snd_ump_dev_register,
+	.dev_unregister = snd_ump_dev_unregister,
+	.ioctl = snd_ump_ioctl,
+	.proc_read = snd_ump_proc_read,
+};
+
+static const struct snd_rawmidi_ops snd_ump_rawmidi_input_ops = {
+	.open = snd_ump_rawmidi_open,
+	.close = snd_ump_rawmidi_close,
+	.trigger = snd_ump_rawmidi_trigger,
+};
+
+static const struct snd_rawmidi_ops snd_ump_rawmidi_output_ops = {
+	.open = snd_ump_rawmidi_open,
+	.close = snd_ump_rawmidi_close,
+	.trigger = snd_ump_rawmidi_trigger,
+	.drain = snd_ump_rawmidi_drain,
+};
+
+static void snd_ump_endpoint_free(struct snd_rawmidi *rmidi)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(rmidi);
+	struct snd_ump_block *fb;
+
+	while (!list_empty(&ump->block_list)) {
+		fb = list_first_entry(&ump->block_list, struct snd_ump_block,
+				      list);
+		list_del(&fb->list);
+		if (fb->private_free)
+			fb->private_free(fb);
+		kfree(fb);
+	}
+
+	if (ump->private_free)
+		ump->private_free(ump);
+
+#if IS_ENABLED(CONFIG_SND_UMP_LEGACY_RAWMIDI)
+	kfree(ump->out_cvts);
+#endif
+}
+
+/**
+ * snd_ump_endpoint_new - create a UMP Endpoint object
+ * @card: the card instance
+ * @id: the id string for rawmidi
+ * @device: the device index for rawmidi
+ * @output: 1 for enabling output
+ * @input: 1 for enabling input
+ * @ump_ret: the pointer to store the new UMP instance
+ *
+ * Creates a new UMP Endpoint object. A UMP Endpoint is tied with one rawmidi
+ * instance with one input and/or one output rawmidi stream (either uni-
+ * or bi-directional). A UMP Endpoint may contain one or multiple UMP Blocks
+ * that consist of one or multiple UMP Groups.
+ *
+ * Use snd_rawmidi_set_ops() to set the operators to the new instance.
+ * Unlike snd_rawmidi_new(), this function sets up the info_flags by itself
+ * depending on the given @output and @input.
+ *
+ * The device has SNDRV_RAWMIDI_INFO_UMP flag set and a different device
+ * file ("umpCxDx") than a standard MIDI 1.x device ("midiCxDx") is
+ * created.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_ump_endpoint_new(struct snd_card *card, char *id, int device,
+			 int output, int input,
+			 struct snd_ump_endpoint **ump_ret)
+{
+	unsigned int info_flags = SNDRV_RAWMIDI_INFO_UMP;
+	struct snd_ump_endpoint *ump;
+	int err;
+
+	if (input)
+		info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+	if (output)
+		info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+	if (input && output)
+		info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	ump = kzalloc(sizeof(*ump), GFP_KERNEL);
+	if (!ump)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&ump->block_list);
+	mutex_init(&ump->open_mutex);
+	init_waitqueue_head(&ump->stream_wait);
+#if IS_ENABLED(CONFIG_SND_UMP_LEGACY_RAWMIDI)
+	spin_lock_init(&ump->legacy_locks[0]);
+	spin_lock_init(&ump->legacy_locks[1]);
+#endif
+	err = snd_rawmidi_init(&ump->core, card, id, device,
+			       output, input, info_flags);
+	if (err < 0) {
+		snd_rawmidi_free(&ump->core);
+		return err;
+	}
+
+	ump->info.card = card->number;
+	ump->info.device = device;
+
+	ump->core.private_free = snd_ump_endpoint_free;
+	ump->core.ops = &snd_ump_rawmidi_ops;
+	if (input)
+		snd_rawmidi_set_ops(&ump->core, SNDRV_RAWMIDI_STREAM_INPUT,
+				    &snd_ump_rawmidi_input_ops);
+	if (output)
+		snd_rawmidi_set_ops(&ump->core, SNDRV_RAWMIDI_STREAM_OUTPUT,
+				    &snd_ump_rawmidi_output_ops);
+
+	ump_dbg(ump, "Created a UMP EP #%d (%s)\n", device, id);
+	*ump_ret = ump;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ump_endpoint_new);
+
+/*
+ * Device register / unregister hooks;
+ *  do nothing, placeholders for avoiding the default rawmidi handling
+ */
+
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+static void snd_ump_dev_seq_free(struct snd_seq_device *device)
+{
+	struct snd_ump_endpoint *ump = device->private_data;
+
+	ump->seq_dev = NULL;
+}
+#endif
+
+static int snd_ump_dev_register(struct snd_rawmidi *rmidi)
+{
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(rmidi);
+	int err;
+
+	err = snd_seq_device_new(ump->core.card, ump->core.device,
+				 SNDRV_SEQ_DEV_ID_UMP, 0, &ump->seq_dev);
+	if (err < 0)
+		return err;
+	ump->seq_dev->private_data = ump;
+	ump->seq_dev->private_free = snd_ump_dev_seq_free;
+	snd_device_register(ump->core.card, ump->seq_dev);
+#endif
+	return 0;
+}
+
+static int snd_ump_dev_unregister(struct snd_rawmidi *rmidi)
+{
+	return 0;
+}
+
+static struct snd_ump_block *
+snd_ump_get_block(struct snd_ump_endpoint *ump, unsigned char id)
+{
+	struct snd_ump_block *fb;
+
+	list_for_each_entry(fb, &ump->block_list, list) {
+		if (fb->info.block_id == id)
+			return fb;
+	}
+	return NULL;
+}
+
+/*
+ * rawmidi ops for UMP endpoint
+ */
+static int snd_ump_rawmidi_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(substream->rmidi);
+	int dir = substream->stream;
+	int err;
+
+	if (ump->substreams[dir])
+		return -EBUSY;
+	err = ump->ops->open(ump, dir);
+	if (err < 0)
+		return err;
+	ump->substreams[dir] = substream;
+	return 0;
+}
+
+static int snd_ump_rawmidi_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(substream->rmidi);
+	int dir = substream->stream;
+
+	ump->substreams[dir] = NULL;
+	ump->ops->close(ump, dir);
+	return 0;
+}
+
+static void snd_ump_rawmidi_trigger(struct snd_rawmidi_substream *substream,
+				    int up)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(substream->rmidi);
+	int dir = substream->stream;
+
+	ump->ops->trigger(ump, dir, up);
+}
+
+static void snd_ump_rawmidi_drain(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(substream->rmidi);
+
+	if (ump->ops->drain)
+		ump->ops->drain(ump, SNDRV_RAWMIDI_STREAM_OUTPUT);
+}
+
+/* number of 32bit words per message type */
+static unsigned char ump_packet_words[0x10] = {
+	1, 1, 1, 2, 2, 4, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4
+};
+
+/**
+ * snd_ump_receive_ump_val - parse the UMP packet data
+ * @ump: UMP endpoint
+ * @val: UMP packet data
+ *
+ * The data is copied onto ump->input_buf[].
+ * When a full packet is completed, returns the number of words (from 1 to 4).
+ * OTOH, if the packet is incomplete, returns 0.
+ */
+int snd_ump_receive_ump_val(struct snd_ump_endpoint *ump, u32 val)
+{
+	int words;
+
+	if (!ump->input_pending)
+		ump->input_pending = ump_packet_words[ump_message_type(val)];
+
+	ump->input_buf[ump->input_buf_head++] = val;
+	ump->input_pending--;
+	if (!ump->input_pending) {
+		words = ump->input_buf_head;
+		ump->input_buf_head = 0;
+		return words;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ump_receive_ump_val);
+
+/**
+ * snd_ump_receive - transfer UMP packets from the device
+ * @ump: the UMP endpoint
+ * @buffer: the buffer pointer to transfer
+ * @count: byte size to transfer
+ *
+ * Called from the driver to submit the received UMP packets from the device
+ * to user-space.  It's essentially a wrapper of rawmidi_receive().
+ * The data to receive is in CPU-native endianness.
+ */
+int snd_ump_receive(struct snd_ump_endpoint *ump, const u32 *buffer, int count)
+{
+	struct snd_rawmidi_substream *substream;
+	const u32 *p = buffer;
+	int n, words = count >> 2;
+
+	while (words--) {
+		n = snd_ump_receive_ump_val(ump, *p++);
+		if (!n)
+			continue;
+		ump_handle_stream_msg(ump, ump->input_buf, n);
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+		if (ump->seq_ops)
+			ump->seq_ops->input_receive(ump, ump->input_buf, n);
+#endif
+		process_legacy_input(ump, ump->input_buf, n);
+	}
+
+	substream = ump->substreams[SNDRV_RAWMIDI_STREAM_INPUT];
+	if (!substream)
+		return 0;
+	return snd_rawmidi_receive(substream, (const char *)buffer, count);
+}
+EXPORT_SYMBOL_GPL(snd_ump_receive);
+
+/**
+ * snd_ump_transmit - transmit UMP packets
+ * @ump: the UMP endpoint
+ * @buffer: the buffer pointer to transfer
+ * @count: byte size to transfer
+ *
+ * Called from the driver to obtain the UMP packets from user-space to the
+ * device.  It's essentially a wrapper of rawmidi_transmit().
+ * The data to transmit is in CPU-native endianness.
+ */
+int snd_ump_transmit(struct snd_ump_endpoint *ump, u32 *buffer, int count)
+{
+	struct snd_rawmidi_substream *substream =
+		ump->substreams[SNDRV_RAWMIDI_STREAM_OUTPUT];
+	int err;
+
+	if (!substream)
+		return -ENODEV;
+	err = snd_rawmidi_transmit(substream, (char *)buffer, count);
+	/* received either data or an error? */
+	if (err)
+		return err;
+	return process_legacy_output(ump, buffer, count);
+}
+EXPORT_SYMBOL_GPL(snd_ump_transmit);
+
+/**
+ * snd_ump_block_new - Create a UMP block
+ * @ump: UMP object
+ * @blk: block ID number to create
+ * @direction: direction (in/out/bidirection)
+ * @first_group: the first group ID (0-based)
+ * @num_groups: the number of groups in this block
+ * @blk_ret: the pointer to store the resultant block object
+ */
+int snd_ump_block_new(struct snd_ump_endpoint *ump, unsigned int blk,
+		      unsigned int direction, unsigned int first_group,
+		      unsigned int num_groups, struct snd_ump_block **blk_ret)
+{
+	struct snd_ump_block *fb, *p;
+
+	if (blk < 0 || blk >= SNDRV_UMP_MAX_BLOCKS)
+		return -EINVAL;
+
+	if (snd_ump_get_block(ump, blk))
+		return -EBUSY;
+
+	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+	if (!fb)
+		return -ENOMEM;
+
+	fb->ump = ump;
+	fb->info.card = ump->info.card;
+	fb->info.device = ump->info.device;
+	fb->info.block_id = blk;
+	if (blk >= ump->info.num_blocks)
+		ump->info.num_blocks = blk + 1;
+	fb->info.direction = direction;
+	fb->info.active = 1;
+	fb->info.first_group = first_group;
+	fb->info.num_groups = num_groups;
+	/* fill the default name, may be overwritten to a better name */
+	snprintf(fb->info.name, sizeof(fb->info.name), "Group %d-%d",
+		 first_group + 1, first_group + num_groups);
+
+	/* put the entry in the ordered list */
+	list_for_each_entry(p, &ump->block_list, list) {
+		if (p->info.block_id > blk) {
+			list_add_tail(&fb->list, &p->list);
+			goto added;
+		}
+	}
+	list_add_tail(&fb->list, &ump->block_list);
+
+ added:
+	ump_dbg(ump, "Created a UMP Block #%d (%s)\n", blk, fb->info.name);
+	*blk_ret = fb;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ump_block_new);
+
+static int snd_ump_ioctl_block(struct snd_ump_endpoint *ump,
+			       struct snd_ump_block_info __user *argp)
+{
+	struct snd_ump_block *fb;
+	unsigned char id;
+
+	if (get_user(id, &argp->block_id))
+		return -EFAULT;
+	fb = snd_ump_get_block(ump, id);
+	if (!fb)
+		return -ENOENT;
+	if (copy_to_user(argp, &fb->info, sizeof(fb->info)))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * Handle UMP-specific ioctls; called from snd_rawmidi_ioctl()
+ */
+static long snd_ump_ioctl(struct snd_rawmidi *rmidi, unsigned int cmd,
+			  void __user *argp)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(rmidi);
+
+	switch (cmd) {
+	case SNDRV_UMP_IOCTL_ENDPOINT_INFO:
+		if (copy_to_user(argp, &ump->info, sizeof(ump->info)))
+			return -EFAULT;
+		return 0;
+	case SNDRV_UMP_IOCTL_BLOCK_INFO:
+		return snd_ump_ioctl_block(ump, argp);
+	default:
+		ump_dbg(ump, "rawmidi: unknown command = 0x%x\n", cmd);
+		return -ENOTTY;
+	}
+}
+
+static const char *ump_direction_string(int dir)
+{
+	switch (dir) {
+	case SNDRV_UMP_DIR_INPUT:
+		return "input";
+	case SNDRV_UMP_DIR_OUTPUT:
+		return "output";
+	case SNDRV_UMP_DIR_BIDIRECTION:
+		return "bidirection";
+	default:
+		return "unknown";
+	}
+}
+
+static const char *ump_ui_hint_string(int dir)
+{
+	switch (dir) {
+	case  SNDRV_UMP_BLOCK_UI_HINT_RECEIVER:
+		return "receiver";
+	case SNDRV_UMP_BLOCK_UI_HINT_SENDER:
+		return "sender";
+	case SNDRV_UMP_BLOCK_UI_HINT_BOTH:
+		return "both";
+	default:
+		return "unknown";
+	}
+}
+
+/* Additional proc file output */
+static void snd_ump_proc_read(struct snd_info_entry *entry,
+			      struct snd_info_buffer *buffer)
+{
+	struct snd_rawmidi *rmidi = entry->private_data;
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(rmidi);
+	struct snd_ump_block *fb;
+
+	snd_iprintf(buffer, "EP Name: %s\n", ump->info.name);
+	snd_iprintf(buffer, "EP Product ID: %s\n", ump->info.product_id);
+	snd_iprintf(buffer, "UMP Version: 0x%04x\n", ump->info.version);
+	snd_iprintf(buffer, "Protocol Caps: 0x%08x\n", ump->info.protocol_caps);
+	snd_iprintf(buffer, "Protocol: 0x%08x\n", ump->info.protocol);
+	if (ump->info.version) {
+		snd_iprintf(buffer, "Manufacturer ID: 0x%08x\n",
+			    ump->info.manufacturer_id);
+		snd_iprintf(buffer, "Family ID: 0x%04x\n", ump->info.family_id);
+		snd_iprintf(buffer, "Model ID: 0x%04x\n", ump->info.model_id);
+		snd_iprintf(buffer, "SW Revision: 0x%02x%02x%02x%02x\n",
+			    ump->info.sw_revision[0],
+			    ump->info.sw_revision[1],
+			    ump->info.sw_revision[2],
+			    ump->info.sw_revision[3]);
+	}
+	snd_iprintf(buffer, "Static Blocks: %s\n",
+		    (ump->info.flags & SNDRV_UMP_EP_INFO_STATIC_BLOCKS) ? "Yes" : "No");
+	snd_iprintf(buffer, "Num Blocks: %d\n\n", ump->info.num_blocks);
+
+	list_for_each_entry(fb, &ump->block_list, list) {
+		snd_iprintf(buffer, "Block %d (%s)\n", fb->info.block_id,
+			    fb->info.name);
+		snd_iprintf(buffer, "  Direction: %s\n",
+			    ump_direction_string(fb->info.direction));
+		snd_iprintf(buffer, "  Active: %s\n",
+			    fb->info.active ? "Yes" : "No");
+		snd_iprintf(buffer, "  Groups: %d-%d\n",
+			    fb->info.first_group + 1,
+			    fb->info.first_group + fb->info.num_groups);
+		snd_iprintf(buffer, "  Is MIDI1: %s%s\n",
+			    (fb->info.flags & SNDRV_UMP_BLOCK_IS_MIDI1) ? "Yes" : "No",
+			    (fb->info.flags & SNDRV_UMP_BLOCK_IS_LOWSPEED) ? " (Low Speed)" : "");
+		if (ump->info.version) {
+			snd_iprintf(buffer, "  MIDI-CI Version: %d\n",
+				    fb->info.midi_ci_version);
+			snd_iprintf(buffer, "  Sysex8 Streams: %d\n",
+				    fb->info.sysex8_streams);
+			snd_iprintf(buffer, "  UI Hint: %s\n",
+				    ump_ui_hint_string(fb->info.ui_hint));
+		}
+		snd_iprintf(buffer, "\n");
+	}
+}
+
+/*
+ * UMP endpoint and function block handling
+ */
+
+/* open / close UMP streams for the internal stream msg communication */
+static int ump_request_open(struct snd_ump_endpoint *ump)
+{
+	return snd_rawmidi_kernel_open(&ump->core, 0,
+				       SNDRV_RAWMIDI_LFLG_OUTPUT,
+				       &ump->stream_rfile);
+}
+
+static void ump_request_close(struct snd_ump_endpoint *ump)
+{
+	snd_rawmidi_kernel_release(&ump->stream_rfile);
+}
+
+/* request a command and wait for the given response;
+ * @req1 and @req2 are u32 commands
+ * @reply is the expected UMP stream status
+ */
+static int ump_req_msg(struct snd_ump_endpoint *ump, u32 req1, u32 req2,
+		       u32 reply)
+{
+	u32 buf[4];
+
+	ump_dbg(ump, "%s: request %08x %08x, wait-for %08x\n",
+		__func__, req1, req2, reply);
+	memset(buf, 0, sizeof(buf));
+	buf[0] = req1;
+	buf[1] = req2;
+	ump->stream_finished = 0;
+	ump->stream_wait_for = reply;
+	snd_rawmidi_kernel_write(ump->stream_rfile.output,
+				 (unsigned char *)&buf, 16);
+	wait_event_timeout(ump->stream_wait, ump->stream_finished,
+			   msecs_to_jiffies(500));
+	if (!READ_ONCE(ump->stream_finished)) {
+		ump_dbg(ump, "%s: request timed out\n", __func__);
+		return -ETIMEDOUT;
+	}
+	ump->stream_finished = 0;
+	ump_dbg(ump, "%s: reply: %08x %08x %08x %08x\n",
+		__func__, buf[0], buf[1], buf[2], buf[3]);
+	return 0;
+}
+
+/* append the received letters via UMP packet to the given string buffer;
+ * return 1 if the full string is received or 0 to continue
+ */
+static int ump_append_string(struct snd_ump_endpoint *ump, char *dest,
+			     int maxsize, const u32 *buf, int offset)
+{
+	unsigned char format;
+	int c;
+
+	format = ump_stream_message_format(buf[0]);
+	if (format == UMP_STREAM_MSG_FORMAT_SINGLE ||
+	    format == UMP_STREAM_MSG_FORMAT_START) {
+		c = 0;
+	} else {
+		c = strlen(dest);
+		if (c >= maxsize - 1)
+			return 1;
+	}
+
+	for (; offset < 16; offset++) {
+		dest[c] = buf[offset / 4] >> (3 - (offset % 4)) * 8;
+		if (!dest[c])
+			break;
+		if (++c >= maxsize - 1)
+			break;
+	}
+	dest[c] = 0;
+	return (format == UMP_STREAM_MSG_FORMAT_SINGLE ||
+		format == UMP_STREAM_MSG_FORMAT_END);
+}
+
+/* handle EP info stream message; update the UMP attributes */
+static int ump_handle_ep_info_msg(struct snd_ump_endpoint *ump,
+				  const union snd_ump_stream_msg *buf)
+{
+	ump->info.version = (buf->ep_info.ump_version_major << 8) |
+		buf->ep_info.ump_version_minor;
+	ump->info.num_blocks = buf->ep_info.num_function_blocks;
+	if (ump->info.num_blocks > SNDRV_UMP_MAX_BLOCKS) {
+		ump_info(ump, "Invalid function blocks %d, fallback to 1\n",
+			 ump->info.num_blocks);
+		ump->info.num_blocks = 1;
+	}
+
+	if (buf->ep_info.static_function_block)
+		ump->info.flags |= SNDRV_UMP_EP_INFO_STATIC_BLOCKS;
+
+	ump->info.protocol_caps = (buf->ep_info.protocol << 8) |
+		buf->ep_info.jrts;
+
+	ump_dbg(ump, "EP info: version=%x, num_blocks=%x, proto_caps=%x\n",
+		ump->info.version, ump->info.num_blocks, ump->info.protocol_caps);
+	return 1; /* finished */
+}
+
+/* handle EP device info stream message; update the UMP attributes */
+static int ump_handle_device_info_msg(struct snd_ump_endpoint *ump,
+				      const union snd_ump_stream_msg *buf)
+{
+	ump->info.manufacturer_id = buf->device_info.manufacture_id & 0x7f7f7f;
+	ump->info.family_id = (buf->device_info.family_msb << 8) |
+		buf->device_info.family_lsb;
+	ump->info.model_id = (buf->device_info.model_msb << 8) |
+		buf->device_info.model_lsb;
+	ump->info.sw_revision[0] = (buf->device_info.sw_revision >> 24) & 0x7f;
+	ump->info.sw_revision[1] = (buf->device_info.sw_revision >> 16) & 0x7f;
+	ump->info.sw_revision[2] = (buf->device_info.sw_revision >> 8) & 0x7f;
+	ump->info.sw_revision[3] = buf->device_info.sw_revision & 0x7f;
+	ump_dbg(ump, "EP devinfo: manid=%08x, family=%04x, model=%04x, sw=%02x%02x%02x%02x\n",
+		ump->info.manufacturer_id,
+		ump->info.family_id,
+		ump->info.model_id,
+		ump->info.sw_revision[0],
+		ump->info.sw_revision[1],
+		ump->info.sw_revision[2],
+		ump->info.sw_revision[3]);
+	return 1; /* finished */
+}
+
+/* handle EP name stream message; update the UMP name string */
+static int ump_handle_ep_name_msg(struct snd_ump_endpoint *ump,
+				  const union snd_ump_stream_msg *buf)
+{
+	return ump_append_string(ump, ump->info.name, sizeof(ump->info.name),
+				 buf->raw, 2);
+}
+
+/* handle EP product id stream message; update the UMP product_id string */
+static int ump_handle_product_id_msg(struct snd_ump_endpoint *ump,
+				     const union snd_ump_stream_msg *buf)
+{
+	return ump_append_string(ump, ump->info.product_id,
+				 sizeof(ump->info.product_id),
+				 buf->raw, 2);
+}
+
+/* notify the protocol change to sequencer */
+static void seq_notify_protocol(struct snd_ump_endpoint *ump)
+{
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+	if (ump->seq_ops && ump->seq_ops->switch_protocol)
+		ump->seq_ops->switch_protocol(ump);
+#endif /* CONFIG_SND_SEQUENCER */
+}
+
+/**
+ * snd_ump_switch_protocol - switch MIDI protocol
+ * @ump: UMP endpoint
+ * @protocol: protocol to switch to
+ *
+ * Returns 1 if the protocol is actually switched, 0 if unchanged
+ */
+int snd_ump_switch_protocol(struct snd_ump_endpoint *ump, unsigned int protocol)
+{
+	protocol &= ump->info.protocol_caps;
+	if (protocol == ump->info.protocol)
+		return 0;
+
+	ump->info.protocol = protocol;
+	ump_dbg(ump, "New protocol = %x (caps = %x)\n",
+		protocol, ump->info.protocol_caps);
+	seq_notify_protocol(ump);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(snd_ump_switch_protocol);
+
+/* handle EP stream config message; update the UMP protocol */
+static int ump_handle_stream_cfg_msg(struct snd_ump_endpoint *ump,
+				     const union snd_ump_stream_msg *buf)
+{
+	unsigned int protocol =
+		(buf->stream_cfg.protocol << 8) | buf->stream_cfg.jrts;
+
+	snd_ump_switch_protocol(ump, protocol);
+	return 1; /* finished */
+}
+
+/* Extract Function Block info from UMP packet */
+static void fill_fb_info(struct snd_ump_endpoint *ump,
+			 struct snd_ump_block_info *info,
+			 const union snd_ump_stream_msg *buf)
+{
+	info->direction = buf->fb_info.direction;
+	info->ui_hint = buf->fb_info.ui_hint;
+	info->first_group = buf->fb_info.first_group;
+	info->num_groups = buf->fb_info.num_groups;
+	info->flags = buf->fb_info.midi_10;
+	info->active = buf->fb_info.active;
+	info->midi_ci_version = buf->fb_info.midi_ci_version;
+	info->sysex8_streams = buf->fb_info.sysex8_streams;
+
+	ump_dbg(ump, "FB %d: dir=%d, active=%d, first_gp=%d, num_gp=%d, midici=%d, sysex8=%d, flags=0x%x\n",
+		info->block_id, info->direction, info->active,
+		info->first_group, info->num_groups, info->midi_ci_version,
+		info->sysex8_streams, info->flags);
+}
+
+/* check whether the FB info gets updated by the current message */
+static bool is_fb_info_updated(struct snd_ump_endpoint *ump,
+			       struct snd_ump_block *fb,
+			       const union snd_ump_stream_msg *buf)
+{
+	char tmpbuf[offsetof(struct snd_ump_block_info, name)];
+
+	if (ump->info.flags & SNDRV_UMP_EP_INFO_STATIC_BLOCKS) {
+		ump_info(ump, "Skipping static FB info update (blk#%d)\n",
+			 fb->info.block_id);
+		return 0;
+	}
+
+	memcpy(tmpbuf, &fb->info, sizeof(tmpbuf));
+	fill_fb_info(ump, (struct snd_ump_block_info *)tmpbuf, buf);
+	return memcmp(&fb->info, tmpbuf, sizeof(tmpbuf)) != 0;
+}
+
+/* notify the FB info/name change to sequencer */
+static void seq_notify_fb_change(struct snd_ump_endpoint *ump,
+				 struct snd_ump_block *fb)
+{
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+	if (ump->seq_ops && ump->seq_ops->notify_fb_change)
+		ump->seq_ops->notify_fb_change(ump, fb);
+#endif
+}
+
+/* handle FB info message; update FB info if the block is present */
+static int ump_handle_fb_info_msg(struct snd_ump_endpoint *ump,
+				  const union snd_ump_stream_msg *buf)
+{
+	unsigned char blk;
+	struct snd_ump_block *fb;
+
+	blk = buf->fb_info.function_block_id;
+	fb = snd_ump_get_block(ump, blk);
+
+	/* complain only if updated after parsing */
+	if (!fb && ump->parsed) {
+		ump_info(ump, "Function Block Info Update for non-existing block %d\n",
+			 blk);
+		return -ENODEV;
+	}
+
+	/* When updated after the initial parse, check the FB info update */
+	if (ump->parsed && !is_fb_info_updated(ump, fb, buf))
+		return 1; /* no content change */
+
+	if (fb) {
+		fill_fb_info(ump, &fb->info, buf);
+		if (ump->parsed)
+			seq_notify_fb_change(ump, fb);
+	}
+
+	return 1; /* finished */
+}
+
+/* handle FB name message; update the FB name string */
+static int ump_handle_fb_name_msg(struct snd_ump_endpoint *ump,
+				  const union snd_ump_stream_msg *buf)
+{
+	unsigned char blk;
+	struct snd_ump_block *fb;
+	int ret;
+
+	blk = buf->fb_name.function_block_id;
+	fb = snd_ump_get_block(ump, blk);
+	if (!fb)
+		return -ENODEV;
+
+	ret = ump_append_string(ump, fb->info.name, sizeof(fb->info.name),
+				buf->raw, 3);
+	/* notify the FB name update to sequencer, too */
+	if (ret > 0 && ump->parsed)
+		seq_notify_fb_change(ump, fb);
+	return ret;
+}
+
+static int create_block_from_fb_info(struct snd_ump_endpoint *ump, int blk)
+{
+	struct snd_ump_block *fb;
+	unsigned char direction, first_group, num_groups;
+	const union snd_ump_stream_msg *buf =
+		(const union snd_ump_stream_msg *)ump->input_buf;
+	u32 msg;
+	int err;
+
+	/* query the FB info once */
+	msg = ump_stream_compose(UMP_STREAM_MSG_STATUS_FB_DISCOVERY, 0) |
+		(blk << 8) | UMP_STREAM_MSG_REQUEST_FB_INFO;
+	err = ump_req_msg(ump, msg, 0, UMP_STREAM_MSG_STATUS_FB_INFO);
+	if (err < 0) {
+		ump_dbg(ump, "Unable to get FB info for block %d\n", blk);
+		return err;
+	}
+
+	/* the last input must be the FB info */
+	if (buf->fb_info.status != UMP_STREAM_MSG_STATUS_FB_INFO) {
+		ump_dbg(ump, "Inconsistent input: 0x%x\n", *buf->raw);
+		return -EINVAL;
+	}
+
+	direction = buf->fb_info.direction;
+	first_group = buf->fb_info.first_group;
+	num_groups = buf->fb_info.num_groups;
+
+	err = snd_ump_block_new(ump, blk, direction, first_group, num_groups,
+				&fb);
+	if (err < 0)
+		return err;
+
+	fill_fb_info(ump, &fb->info, buf);
+
+	msg = ump_stream_compose(UMP_STREAM_MSG_STATUS_FB_DISCOVERY, 0) |
+		(blk << 8) | UMP_STREAM_MSG_REQUEST_FB_NAME;
+	err = ump_req_msg(ump, msg, 0, UMP_STREAM_MSG_STATUS_FB_NAME);
+	if (err)
+		ump_dbg(ump, "Unable to get UMP FB name string #%d\n", blk);
+
+	return 0;
+}
+
+/* handle stream messages, called from snd_ump_receive() */
+static void ump_handle_stream_msg(struct snd_ump_endpoint *ump,
+				  const u32 *buf, int size)
+{
+	const union snd_ump_stream_msg *msg;
+	unsigned int status;
+	int ret;
+
+	/* UMP stream message suppressed (for gadget UMP)? */
+	if (ump->no_process_stream)
+		return;
+
+	BUILD_BUG_ON(sizeof(*msg) != 16);
+	ump_dbg(ump, "Stream msg: %08x %08x %08x %08x\n",
+		buf[0], buf[1], buf[2], buf[3]);
+
+	if (size != 4 || ump_message_type(*buf) != UMP_MSG_TYPE_STREAM)
+		return;
+
+	msg = (const union snd_ump_stream_msg *)buf;
+	status = ump_stream_message_status(*buf);
+	switch (status) {
+	case UMP_STREAM_MSG_STATUS_EP_INFO:
+		ret = ump_handle_ep_info_msg(ump, msg);
+		break;
+	case UMP_STREAM_MSG_STATUS_DEVICE_INFO:
+		ret = ump_handle_device_info_msg(ump, msg);
+		break;
+	case UMP_STREAM_MSG_STATUS_EP_NAME:
+		ret = ump_handle_ep_name_msg(ump, msg);
+		break;
+	case UMP_STREAM_MSG_STATUS_PRODUCT_ID:
+		ret = ump_handle_product_id_msg(ump, msg);
+		break;
+	case UMP_STREAM_MSG_STATUS_STREAM_CFG:
+		ret = ump_handle_stream_cfg_msg(ump, msg);
+		break;
+	case UMP_STREAM_MSG_STATUS_FB_INFO:
+		ret = ump_handle_fb_info_msg(ump, msg);
+		break;
+	case UMP_STREAM_MSG_STATUS_FB_NAME:
+		ret = ump_handle_fb_name_msg(ump, msg);
+		break;
+	default:
+		return;
+	}
+
+	/* when the message has been processed fully, wake up */
+	if (ret > 0 && ump->stream_wait_for == status) {
+		WRITE_ONCE(ump->stream_finished, 1);
+		wake_up(&ump->stream_wait);
+	}
+}
+
+/**
+ * snd_ump_parse_endpoint - parse endpoint and create function blocks
+ * @ump: UMP object
+ *
+ * Returns 0 for successful parse, -ENODEV if device doesn't respond
+ * (or the query is unsupported), or other error code for serious errors.
+ */
+int snd_ump_parse_endpoint(struct snd_ump_endpoint *ump)
+{
+	int blk, err;
+	u32 msg;
+
+	if (!(ump->core.info_flags & SNDRV_RAWMIDI_INFO_DUPLEX))
+		return -ENODEV;
+
+	err = ump_request_open(ump);
+	if (err < 0) {
+		ump_dbg(ump, "Unable to open rawmidi device: %d\n", err);
+		return err;
+	}
+
+	/* Check Endpoint Information */
+	msg = ump_stream_compose(UMP_STREAM_MSG_STATUS_EP_DISCOVERY, 0) |
+		0x0101; /* UMP version 1.1 */
+	err = ump_req_msg(ump, msg, UMP_STREAM_MSG_REQUEST_EP_INFO,
+			  UMP_STREAM_MSG_STATUS_EP_INFO);
+	if (err < 0) {
+		ump_dbg(ump, "Unable to get UMP EP info\n");
+		goto error;
+	}
+
+	/* Request Endpoint Device Info */
+	err = ump_req_msg(ump, msg, UMP_STREAM_MSG_REQUEST_DEVICE_INFO,
+			  UMP_STREAM_MSG_STATUS_DEVICE_INFO);
+	if (err < 0)
+		ump_dbg(ump, "Unable to get UMP EP device info\n");
+
+	/* Request Endpoint Name */
+	err = ump_req_msg(ump, msg, UMP_STREAM_MSG_REQUEST_EP_NAME,
+			  UMP_STREAM_MSG_STATUS_EP_NAME);
+	if (err < 0)
+		ump_dbg(ump, "Unable to get UMP EP name string\n");
+
+	/* Request Endpoint Product ID */
+	err = ump_req_msg(ump, msg, UMP_STREAM_MSG_REQUEST_PRODUCT_ID,
+			  UMP_STREAM_MSG_STATUS_PRODUCT_ID);
+	if (err < 0)
+		ump_dbg(ump, "Unable to get UMP EP product ID string\n");
+
+	/* Get the current stream configuration */
+	err = ump_req_msg(ump, msg, UMP_STREAM_MSG_REQUEST_STREAM_CFG,
+			  UMP_STREAM_MSG_STATUS_STREAM_CFG);
+	if (err < 0)
+		ump_dbg(ump, "Unable to get UMP EP stream config\n");
+
+	/* Query and create blocks from Function Blocks */
+	for (blk = 0; blk < ump->info.num_blocks; blk++) {
+		err = create_block_from_fb_info(ump, blk);
+		if (err < 0)
+			continue;
+	}
+
+ error:
+	ump->parsed = true;
+	ump_request_close(ump);
+	if (err == -ETIMEDOUT)
+		err = -ENODEV;
+	return err;
+}
+EXPORT_SYMBOL_GPL(snd_ump_parse_endpoint);
+
+#if IS_ENABLED(CONFIG_SND_UMP_LEGACY_RAWMIDI)
+/*
+ * Legacy rawmidi support
+ */
+static int snd_ump_legacy_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = substream->rmidi->private_data;
+	int dir = substream->stream;
+	int group = ump->legacy_mapping[substream->number];
+	int err;
+
+	mutex_lock(&ump->open_mutex);
+	if (ump->legacy_substreams[dir][group]) {
+		err = -EBUSY;
+		goto unlock;
+	}
+	if (dir == SNDRV_RAWMIDI_STREAM_OUTPUT) {
+		if (!ump->legacy_out_opens) {
+			err = snd_rawmidi_kernel_open(&ump->core, 0,
+						      SNDRV_RAWMIDI_LFLG_OUTPUT |
+						      SNDRV_RAWMIDI_LFLG_APPEND,
+						      &ump->legacy_out_rfile);
+			if (err < 0)
+				goto unlock;
+		}
+		ump->legacy_out_opens++;
+		snd_ump_convert_reset(&ump->out_cvts[group]);
+	}
+	spin_lock_irq(&ump->legacy_locks[dir]);
+	ump->legacy_substreams[dir][group] = substream;
+	spin_unlock_irq(&ump->legacy_locks[dir]);
+ unlock:
+	mutex_unlock(&ump->open_mutex);
+	return 0;
+}
+
+static int snd_ump_legacy_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = substream->rmidi->private_data;
+	int dir = substream->stream;
+	int group = ump->legacy_mapping[substream->number];
+
+	mutex_lock(&ump->open_mutex);
+	spin_lock_irq(&ump->legacy_locks[dir]);
+	ump->legacy_substreams[dir][group] = NULL;
+	spin_unlock_irq(&ump->legacy_locks[dir]);
+	if (dir == SNDRV_RAWMIDI_STREAM_OUTPUT) {
+		if (!--ump->legacy_out_opens)
+			snd_rawmidi_kernel_release(&ump->legacy_out_rfile);
+	}
+	mutex_unlock(&ump->open_mutex);
+	return 0;
+}
+
+static void snd_ump_legacy_trigger(struct snd_rawmidi_substream *substream,
+				   int up)
+{
+	struct snd_ump_endpoint *ump = substream->rmidi->private_data;
+	int dir = substream->stream;
+
+	ump->ops->trigger(ump, dir, up);
+}
+
+static void snd_ump_legacy_drain(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = substream->rmidi->private_data;
+
+	if (ump->ops->drain)
+		ump->ops->drain(ump, SNDRV_RAWMIDI_STREAM_OUTPUT);
+}
+
+static int snd_ump_legacy_dev_register(struct snd_rawmidi *rmidi)
+{
+	/* dummy, just for avoiding create superfluous seq clients */
+	return 0;
+}
+
+static const struct snd_rawmidi_ops snd_ump_legacy_input_ops = {
+	.open = snd_ump_legacy_open,
+	.close = snd_ump_legacy_close,
+	.trigger = snd_ump_legacy_trigger,
+};
+
+static const struct snd_rawmidi_ops snd_ump_legacy_output_ops = {
+	.open = snd_ump_legacy_open,
+	.close = snd_ump_legacy_close,
+	.trigger = snd_ump_legacy_trigger,
+	.drain = snd_ump_legacy_drain,
+};
+
+static const struct snd_rawmidi_global_ops snd_ump_legacy_ops = {
+	.dev_register = snd_ump_legacy_dev_register,
+};
+
+static int process_legacy_output(struct snd_ump_endpoint *ump,
+				 u32 *buffer, int count)
+{
+	struct snd_rawmidi_substream *substream;
+	struct ump_cvt_to_ump *ctx;
+	const int dir = SNDRV_RAWMIDI_STREAM_OUTPUT;
+	unsigned char c;
+	int group, size = 0;
+	unsigned long flags;
+
+	if (!ump->out_cvts || !ump->legacy_out_opens)
+		return 0;
+
+	spin_lock_irqsave(&ump->legacy_locks[dir], flags);
+	for (group = 0; group < SNDRV_UMP_MAX_GROUPS; group++) {
+		substream = ump->legacy_substreams[dir][group];
+		if (!substream)
+			continue;
+		ctx = &ump->out_cvts[group];
+		while (!ctx->ump_bytes &&
+		       snd_rawmidi_transmit(substream, &c, 1) > 0)
+			snd_ump_convert_to_ump(ctx, group, ump->info.protocol, c);
+		if (ctx->ump_bytes && ctx->ump_bytes <= count) {
+			size = ctx->ump_bytes;
+			memcpy(buffer, ctx->ump, size);
+			ctx->ump_bytes = 0;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&ump->legacy_locks[dir], flags);
+	return size;
+}
+
+static void process_legacy_input(struct snd_ump_endpoint *ump, const u32 *src,
+				 int words)
+{
+	struct snd_rawmidi_substream *substream;
+	unsigned char buf[16];
+	unsigned char group;
+	unsigned long flags;
+	const int dir = SNDRV_RAWMIDI_STREAM_INPUT;
+	int size;
+
+	size = snd_ump_convert_from_ump(src, buf, &group);
+	if (size <= 0)
+		return;
+	spin_lock_irqsave(&ump->legacy_locks[dir], flags);
+	substream = ump->legacy_substreams[dir][group];
+	if (substream)
+		snd_rawmidi_receive(substream, buf, size);
+	spin_unlock_irqrestore(&ump->legacy_locks[dir], flags);
+}
+
+/* Fill ump->legacy_mapping[] for groups to be used for legacy rawmidi */
+static int fill_legacy_mapping(struct snd_ump_endpoint *ump)
+{
+	struct snd_ump_block *fb;
+	unsigned int group_maps = 0;
+	int i, num;
+
+	if (ump->info.flags & SNDRV_UMP_EP_INFO_STATIC_BLOCKS) {
+		list_for_each_entry(fb, &ump->block_list, list) {
+			for (i = 0; i < fb->info.num_groups; i++)
+				group_maps |= 1U << (fb->info.first_group + i);
+		}
+		if (!group_maps)
+			ump_info(ump, "No UMP Group is found in FB\n");
+	}
+
+	/* use all groups for non-static case */
+	if (!group_maps)
+		group_maps = (1U << SNDRV_UMP_MAX_GROUPS) - 1;
+
+	num = 0;
+	for (i = 0; i < SNDRV_UMP_MAX_GROUPS; i++)
+		if (group_maps & (1U << i))
+			ump->legacy_mapping[num++] = i;
+
+	return num;
+}
+
+static void fill_substream_names(struct snd_ump_endpoint *ump,
+				 struct snd_rawmidi *rmidi, int dir)
+{
+	struct snd_rawmidi_substream *s;
+
+	list_for_each_entry(s, &rmidi->streams[dir].substreams, list)
+		snprintf(s->name, sizeof(s->name), "Group %d (%.16s)",
+			 ump->legacy_mapping[s->number] + 1, ump->info.name);
+}
+
+int snd_ump_attach_legacy_rawmidi(struct snd_ump_endpoint *ump,
+				  char *id, int device)
+{
+	struct snd_rawmidi *rmidi;
+	bool input, output;
+	int err, num;
+
+	ump->out_cvts = kcalloc(SNDRV_UMP_MAX_GROUPS,
+				sizeof(*ump->out_cvts), GFP_KERNEL);
+	if (!ump->out_cvts)
+		return -ENOMEM;
+
+	num = fill_legacy_mapping(ump);
+
+	input = ump->core.info_flags & SNDRV_RAWMIDI_INFO_INPUT;
+	output = ump->core.info_flags & SNDRV_RAWMIDI_INFO_OUTPUT;
+	err = snd_rawmidi_new(ump->core.card, id, device,
+			      output ? num : 0, input ? num : 0,
+			      &rmidi);
+	if (err < 0) {
+		kfree(ump->out_cvts);
+		return err;
+	}
+
+	if (input)
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+				    &snd_ump_legacy_input_ops);
+	if (output)
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+				    &snd_ump_legacy_output_ops);
+	snprintf(rmidi->name, sizeof(rmidi->name), "%.68s (MIDI 1.0)",
+		 ump->info.name);
+	rmidi->info_flags = ump->core.info_flags & ~SNDRV_RAWMIDI_INFO_UMP;
+	rmidi->ops = &snd_ump_legacy_ops;
+	rmidi->private_data = ump;
+	ump->legacy_rmidi = rmidi;
+	if (input)
+		fill_substream_names(ump, rmidi, SNDRV_RAWMIDI_STREAM_INPUT);
+	if (output)
+		fill_substream_names(ump, rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT);
+
+	ump_dbg(ump, "Created a legacy rawmidi #%d (%s)\n", device, id);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ump_attach_legacy_rawmidi);
+#endif /* CONFIG_SND_UMP_LEGACY_RAWMIDI */
+
+MODULE_DESCRIPTION("Universal MIDI Packet (UMP) Core Driver");
+MODULE_LICENSE("GPL");
diff --git a/sound/core/ump_convert.c b/sound/core/ump_convert.c
new file mode 100644
index 0000000000..de04799fdb
--- /dev/null
+++ b/sound/core/ump_convert.c
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Helpers for UMP <-> MIDI 1.0 byte stream conversion
+ */
+
+#include <linux/module.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/asound.h>
+#include <sound/ump.h>
+#include <sound/ump_convert.h>
+
+/*
+ * Upgrade / downgrade value bits
+ */
+static u8 downscale_32_to_7bit(u32 src)
+{
+	return src >> 25;
+}
+
+static u16 downscale_32_to_14bit(u32 src)
+{
+	return src >> 18;
+}
+
+static u8 downscale_16_to_7bit(u16 src)
+{
+	return src >> 9;
+}
+
+static u16 upscale_7_to_16bit(u8 src)
+{
+	u16 val, repeat;
+
+	val = (u16)src << 9;
+	if (src <= 0x40)
+		return val;
+	repeat = src & 0x3f;
+	return val | (repeat << 3) | (repeat >> 3);
+}
+
+static u32 upscale_7_to_32bit(u8 src)
+{
+	u32 val, repeat;
+
+	val = src << 25;
+	if (src <= 0x40)
+		return val;
+	repeat = src & 0x3f;
+	return val | (repeat << 19) | (repeat << 13) |
+		(repeat << 7) | (repeat << 1) | (repeat >> 5);
+}
+
+static u32 upscale_14_to_32bit(u16 src)
+{
+	u32 val, repeat;
+
+	val = src << 18;
+	if (src <= 0x2000)
+		return val;
+	repeat = src & 0x1fff;
+	return val | (repeat << 5) | (repeat >> 8);
+}
+
+/*
+ * UMP -> MIDI 1 byte stream conversion
+ */
+/* convert a UMP System message to MIDI 1.0 byte stream */
+static int cvt_ump_system_to_legacy(u32 data, unsigned char *buf)
+{
+	buf[0] = ump_message_status_channel(data);
+	switch (ump_message_status_code(data)) {
+	case UMP_SYSTEM_STATUS_MIDI_TIME_CODE:
+	case UMP_SYSTEM_STATUS_SONG_SELECT:
+		buf[1] = (data >> 8) & 0x7f;
+		return 2;
+	case UMP_SYSTEM_STATUS_SONG_POSITION:
+		buf[1] = (data >> 8) & 0x7f;
+		buf[2] = data & 0x7f;
+		return 3;
+	default:
+		return 1;
+	}
+}
+
+/* convert a UMP MIDI 1.0 Channel Voice message to MIDI 1.0 byte stream */
+static int cvt_ump_midi1_to_legacy(u32 data, unsigned char *buf)
+{
+	buf[0] = ump_message_status_channel(data);
+	buf[1] = (data >> 8) & 0xff;
+	switch (ump_message_status_code(data)) {
+	case UMP_MSG_STATUS_PROGRAM:
+	case UMP_MSG_STATUS_CHANNEL_PRESSURE:
+		return 2;
+	default:
+		buf[2] = data & 0xff;
+		return 3;
+	}
+}
+
+/* convert a UMP MIDI 2.0 Channel Voice message to MIDI 1.0 byte stream */
+static int cvt_ump_midi2_to_legacy(const union snd_ump_midi2_msg *midi2,
+				   unsigned char *buf)
+{
+	unsigned char status = midi2->note.status;
+	unsigned char channel = midi2->note.channel;
+	u16 v;
+
+	buf[0] = (status << 4) | channel;
+	switch (status) {
+	case UMP_MSG_STATUS_NOTE_OFF:
+	case UMP_MSG_STATUS_NOTE_ON:
+		buf[1] = midi2->note.note;
+		buf[2] = downscale_16_to_7bit(midi2->note.velocity);
+		if (status == UMP_MSG_STATUS_NOTE_ON && !buf[2])
+			buf[2] = 1;
+		return 3;
+	case UMP_MSG_STATUS_POLY_PRESSURE:
+		buf[1] = midi2->paf.note;
+		buf[2] = downscale_32_to_7bit(midi2->paf.data);
+		return 3;
+	case UMP_MSG_STATUS_CC:
+		buf[1] = midi2->cc.index;
+		buf[2] = downscale_32_to_7bit(midi2->cc.data);
+		return 3;
+	case UMP_MSG_STATUS_CHANNEL_PRESSURE:
+		buf[1] = downscale_32_to_7bit(midi2->caf.data);
+		return 2;
+	case UMP_MSG_STATUS_PROGRAM:
+		if (midi2->pg.bank_valid) {
+			buf[0] = channel | (UMP_MSG_STATUS_CC << 4);
+			buf[1] = UMP_CC_BANK_SELECT;
+			buf[2] = midi2->pg.bank_msb;
+			buf[3] = channel | (UMP_MSG_STATUS_CC << 4);
+			buf[4] = UMP_CC_BANK_SELECT_LSB;
+			buf[5] = midi2->pg.bank_lsb;
+			buf[6] = channel | (UMP_MSG_STATUS_PROGRAM << 4);
+			buf[7] = midi2->pg.program;
+			return 8;
+		}
+		buf[1] = midi2->pg.program;
+		return 2;
+	case UMP_MSG_STATUS_PITCH_BEND:
+		v = downscale_32_to_14bit(midi2->pb.data);
+		buf[1] = v & 0x7f;
+		buf[2] = v >> 7;
+		return 3;
+	case UMP_MSG_STATUS_RPN:
+	case UMP_MSG_STATUS_NRPN:
+		buf[0] = channel | (UMP_MSG_STATUS_CC << 4);
+		buf[1] = status == UMP_MSG_STATUS_RPN ? UMP_CC_RPN_MSB : UMP_CC_NRPN_MSB;
+		buf[2] = midi2->rpn.bank;
+		buf[3] = buf[0];
+		buf[4] = status == UMP_MSG_STATUS_RPN ? UMP_CC_RPN_LSB : UMP_CC_NRPN_LSB;
+		buf[5] = midi2->rpn.index;
+		buf[6] = buf[0];
+		buf[7] = UMP_CC_DATA;
+		v = downscale_32_to_14bit(midi2->rpn.data);
+		buf[8] = v >> 7;
+		buf[9] = buf[0];
+		buf[10] = UMP_CC_DATA_LSB;
+		buf[11] = v & 0x7f;
+		return 12;
+	default:
+		return 0;
+	}
+}
+
+/* convert a UMP 7-bit SysEx message to MIDI 1.0 byte stream */
+static int cvt_ump_sysex7_to_legacy(const u32 *data, unsigned char *buf)
+{
+	unsigned char status;
+	unsigned char bytes;
+	int size, offset;
+
+	status = ump_sysex_message_status(*data);
+	if (status > UMP_SYSEX_STATUS_END)
+		return 0; // unsupported, skip
+	bytes = ump_sysex_message_length(*data);
+	if (bytes > 6)
+		return 0; // skip
+
+	size = 0;
+	if (status == UMP_SYSEX_STATUS_SINGLE ||
+	    status == UMP_SYSEX_STATUS_START) {
+		buf[0] = UMP_MIDI1_MSG_SYSEX_START;
+		size = 1;
+	}
+
+	offset = 8;
+	for (; bytes; bytes--, size++) {
+		buf[size] = (*data >> offset) & 0x7f;
+		if (!offset) {
+			offset = 24;
+			data++;
+		} else {
+			offset -= 8;
+		}
+	}
+
+	if (status == UMP_SYSEX_STATUS_SINGLE ||
+	    status == UMP_SYSEX_STATUS_END)
+		buf[size++] = UMP_MIDI1_MSG_SYSEX_END;
+
+	return size;
+}
+
+/**
+ * snd_ump_convert_from_ump - convert from UMP to legacy MIDI
+ * @data: UMP packet
+ * @buf: buffer to store legacy MIDI data
+ * @group_ret: pointer to store the target group
+ *
+ * Convert from a UMP packet @data to MIDI 1.0 bytes at @buf.
+ * The target group is stored at @group_ret.
+ *
+ * The function returns the number of bytes of MIDI 1.0 stream.
+ */
+int snd_ump_convert_from_ump(const u32 *data,
+			     unsigned char *buf,
+			     unsigned char *group_ret)
+{
+	*group_ret = ump_message_group(*data);
+
+	switch (ump_message_type(*data)) {
+	case UMP_MSG_TYPE_SYSTEM:
+		return cvt_ump_system_to_legacy(*data, buf);
+	case UMP_MSG_TYPE_MIDI1_CHANNEL_VOICE:
+		return cvt_ump_midi1_to_legacy(*data, buf);
+	case UMP_MSG_TYPE_MIDI2_CHANNEL_VOICE:
+		return cvt_ump_midi2_to_legacy((const union snd_ump_midi2_msg *)data,
+					       buf);
+	case UMP_MSG_TYPE_DATA:
+		return cvt_ump_sysex7_to_legacy(data, buf);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ump_convert_from_ump);
+
+/*
+ * MIDI 1 byte stream -> UMP conversion
+ */
+/* convert MIDI 1.0 SysEx to a UMP packet */
+static int cvt_legacy_sysex_to_ump(struct ump_cvt_to_ump *cvt,
+				   unsigned char group, u32 *data, bool finish)
+{
+	unsigned char status;
+	bool start = cvt->in_sysex == 1;
+	int i, offset;
+
+	if (start && finish)
+		status = UMP_SYSEX_STATUS_SINGLE;
+	else if (start)
+		status = UMP_SYSEX_STATUS_START;
+	else if (finish)
+		status = UMP_SYSEX_STATUS_END;
+	else
+		status = UMP_SYSEX_STATUS_CONTINUE;
+	*data = ump_compose(UMP_MSG_TYPE_DATA, group, status, cvt->len);
+	offset = 8;
+	for (i = 0; i < cvt->len; i++) {
+		*data |= cvt->buf[i] << offset;
+		if (!offset) {
+			offset = 24;
+			data++;
+		} else
+			offset -= 8;
+	}
+	cvt->len = 0;
+	if (finish)
+		cvt->in_sysex = 0;
+	else
+		cvt->in_sysex++;
+	return 8;
+}
+
+/* convert to a UMP System message */
+static int cvt_legacy_system_to_ump(struct ump_cvt_to_ump *cvt,
+				    unsigned char group, u32 *data)
+{
+	data[0] = ump_compose(UMP_MSG_TYPE_SYSTEM, group, 0, cvt->buf[0]);
+	if (cvt->cmd_bytes > 1)
+		data[0] |= cvt->buf[1] << 8;
+	if (cvt->cmd_bytes > 2)
+		data[0] |= cvt->buf[2];
+	return 4;
+}
+
+static void fill_rpn(struct ump_cvt_to_ump_bank *cc,
+		     union snd_ump_midi2_msg *midi2)
+{
+	if (cc->rpn_set) {
+		midi2->rpn.status = UMP_MSG_STATUS_RPN;
+		midi2->rpn.bank = cc->cc_rpn_msb;
+		midi2->rpn.index = cc->cc_rpn_lsb;
+		cc->rpn_set = 0;
+		cc->cc_rpn_msb = cc->cc_rpn_lsb = 0;
+	} else {
+		midi2->rpn.status = UMP_MSG_STATUS_NRPN;
+		midi2->rpn.bank = cc->cc_nrpn_msb;
+		midi2->rpn.index = cc->cc_nrpn_lsb;
+		cc->nrpn_set = 0;
+		cc->cc_nrpn_msb = cc->cc_nrpn_lsb = 0;
+	}
+	midi2->rpn.data = upscale_14_to_32bit((cc->cc_data_msb << 7) |
+					      cc->cc_data_lsb);
+	cc->cc_data_msb = cc->cc_data_lsb = 0;
+}
+
+/* convert to a MIDI 1.0 Channel Voice message */
+static int cvt_legacy_cmd_to_ump(struct ump_cvt_to_ump *cvt,
+				 unsigned char group,
+				 unsigned int protocol,
+				 u32 *data, unsigned char bytes)
+{
+	const unsigned char *buf = cvt->buf;
+	struct ump_cvt_to_ump_bank *cc;
+	union snd_ump_midi2_msg *midi2 = (union snd_ump_midi2_msg *)data;
+	unsigned char status, channel;
+
+	BUILD_BUG_ON(sizeof(union snd_ump_midi1_msg) != 4);
+	BUILD_BUG_ON(sizeof(union snd_ump_midi2_msg) != 8);
+
+	/* for MIDI 1.0 UMP, it's easy, just pack it into UMP */
+	if (protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI1) {
+		data[0] = ump_compose(UMP_MSG_TYPE_MIDI1_CHANNEL_VOICE,
+				      group, 0, buf[0]);
+		data[0] |= buf[1] << 8;
+		if (bytes > 2)
+			data[0] |= buf[2];
+		return 4;
+	}
+
+	status = *buf >> 4;
+	channel = *buf & 0x0f;
+	cc = &cvt->bank[channel];
+
+	/* special handling: treat note-on with 0 velocity as note-off */
+	if (status == UMP_MSG_STATUS_NOTE_ON && !buf[2])
+		status = UMP_MSG_STATUS_NOTE_OFF;
+
+	/* initialize the packet */
+	data[0] = ump_compose(UMP_MSG_TYPE_MIDI2_CHANNEL_VOICE,
+			      group, status, channel);
+	data[1] = 0;
+
+	switch (status) {
+	case UMP_MSG_STATUS_NOTE_ON:
+	case UMP_MSG_STATUS_NOTE_OFF:
+		midi2->note.note = buf[1];
+		midi2->note.velocity = upscale_7_to_16bit(buf[2]);
+		break;
+	case UMP_MSG_STATUS_POLY_PRESSURE:
+		midi2->paf.note = buf[1];
+		midi2->paf.data = upscale_7_to_32bit(buf[2]);
+		break;
+	case UMP_MSG_STATUS_CC:
+		switch (buf[1]) {
+		case UMP_CC_RPN_MSB:
+			cc->rpn_set = 1;
+			cc->cc_rpn_msb = buf[2];
+			return 0; // skip
+		case UMP_CC_RPN_LSB:
+			cc->rpn_set = 1;
+			cc->cc_rpn_lsb = buf[2];
+			return 0; // skip
+		case UMP_CC_NRPN_MSB:
+			cc->nrpn_set = 1;
+			cc->cc_nrpn_msb = buf[2];
+			return 0; // skip
+		case UMP_CC_NRPN_LSB:
+			cc->nrpn_set = 1;
+			cc->cc_nrpn_lsb = buf[2];
+			return 0; // skip
+		case UMP_CC_DATA:
+			cc->cc_data_msb = buf[2];
+			return 0; // skip
+		case UMP_CC_BANK_SELECT:
+			cc->bank_set = 1;
+			cc->cc_bank_msb = buf[2];
+			return 0; // skip
+		case UMP_CC_BANK_SELECT_LSB:
+			cc->bank_set = 1;
+			cc->cc_bank_lsb = buf[2];
+			return 0; // skip
+		case UMP_CC_DATA_LSB:
+			cc->cc_data_lsb = buf[2];
+			if (cc->rpn_set || cc->nrpn_set)
+				fill_rpn(cc, midi2);
+			else
+				return 0; // skip
+			break;
+		default:
+			midi2->cc.index = buf[1];
+			midi2->cc.data = upscale_7_to_32bit(buf[2]);
+			break;
+		}
+		break;
+	case UMP_MSG_STATUS_PROGRAM:
+		midi2->pg.program = buf[1];
+		if (cc->bank_set) {
+			midi2->pg.bank_valid = 1;
+			midi2->pg.bank_msb = cc->cc_bank_msb;
+			midi2->pg.bank_lsb = cc->cc_bank_lsb;
+			cc->bank_set = 0;
+			cc->cc_bank_msb = cc->cc_bank_lsb = 0;
+		}
+		break;
+	case UMP_MSG_STATUS_CHANNEL_PRESSURE:
+		midi2->caf.data = upscale_7_to_32bit(buf[1]);
+		break;
+	case UMP_MSG_STATUS_PITCH_BEND:
+		midi2->pb.data = upscale_14_to_32bit(buf[1] | (buf[2] << 7));
+		break;
+	default:
+		return 0;
+	}
+
+	return 8;
+}
+
+static int do_convert_to_ump(struct ump_cvt_to_ump *cvt, unsigned char group,
+			     unsigned int protocol, unsigned char c, u32 *data)
+{
+	/* bytes for 0x80-0xf0 */
+	static unsigned char cmd_bytes[8] = {
+		3, 3, 3, 3, 2, 2, 3, 0
+	};
+	/* bytes for 0xf0-0xff */
+	static unsigned char system_bytes[16] = {
+		0, 2, 3, 2, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1
+	};
+	unsigned char bytes;
+
+	if (c == UMP_MIDI1_MSG_SYSEX_START) {
+		cvt->in_sysex = 1;
+		cvt->len = 0;
+		return 0;
+	}
+	if (c == UMP_MIDI1_MSG_SYSEX_END) {
+		if (!cvt->in_sysex)
+			return 0; /* skip */
+		return cvt_legacy_sysex_to_ump(cvt, group, data, true);
+	}
+
+	if ((c & 0xf0) == UMP_MIDI1_MSG_REALTIME) {
+		bytes = system_bytes[c & 0x0f];
+		if (!bytes)
+			return 0; /* skip */
+		if (bytes == 1) {
+			data[0] = ump_compose(UMP_MSG_TYPE_SYSTEM, group, 0, c);
+			return 4;
+		}
+		cvt->buf[0] = c;
+		cvt->len = 1;
+		cvt->cmd_bytes = bytes;
+		cvt->in_sysex = 0; /* abort SysEx */
+		return 0;
+	}
+
+	if (c & 0x80) {
+		bytes = cmd_bytes[(c >> 4) & 7];
+		cvt->buf[0] = c;
+		cvt->len = 1;
+		cvt->cmd_bytes = bytes;
+		cvt->in_sysex = 0; /* abort SysEx */
+		return 0;
+	}
+
+	if (cvt->in_sysex) {
+		cvt->buf[cvt->len++] = c;
+		if (cvt->len == 6)
+			return cvt_legacy_sysex_to_ump(cvt, group, data, false);
+		return 0;
+	}
+
+	if (!cvt->len)
+		return 0;
+
+	cvt->buf[cvt->len++] = c;
+	if (cvt->len < cvt->cmd_bytes)
+		return 0;
+	cvt->len = 1;
+	if ((cvt->buf[0] & 0xf0) == UMP_MIDI1_MSG_REALTIME)
+		return cvt_legacy_system_to_ump(cvt, group, data);
+	return cvt_legacy_cmd_to_ump(cvt, group, protocol, data, cvt->cmd_bytes);
+}
+
+/**
+ * snd_ump_convert_to_ump - convert legacy MIDI byte to UMP packet
+ * @cvt: converter context
+ * @group: target UMP group
+ * @protocol: target UMP protocol
+ * @c: MIDI 1.0 byte data
+ *
+ * Feed a MIDI 1.0 byte @c and convert to a UMP packet if completed.
+ * The result is stored in the buffer in @cvt.
+ */
+void snd_ump_convert_to_ump(struct ump_cvt_to_ump *cvt, unsigned char group,
+			    unsigned int protocol, unsigned char c)
+{
+	cvt->ump_bytes = do_convert_to_ump(cvt, group, protocol, c, cvt->ump);
+}
+EXPORT_SYMBOL_GPL(snd_ump_convert_to_ump);
diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
new file mode 100644
index 0000000000..378d2c7c3d
--- /dev/null
+++ b/sound/core/vmaster.c
@@ -0,0 +1,550 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Virtual master and follower controls
+ *
+ *  Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+
+/*
+ * a subset of information returned via ctl info callback
+ */
+struct link_ctl_info {
+	snd_ctl_elem_type_t type; /* value type */
+	int count;		/* item count */
+	int min_val, max_val;	/* min, max values */
+};
+
+/*
+ * link master - this contains a list of follower controls that are
+ * identical types, i.e. info returns the same value type and value
+ * ranges, but may have different number of counts.
+ *
+ * The master control is so far only mono volume/switch for simplicity.
+ * The same value will be applied to all followers.
+ */
+struct link_master {
+	struct list_head followers;
+	struct link_ctl_info info;
+	int val;		/* the master value */
+	unsigned int tlv[4];
+	void (*hook)(void *private_data, int);
+	void *hook_private_data;
+};
+
+/*
+ * link follower - this contains a follower control element
+ *
+ * It fakes the control callbacks with additional attenuation by the
+ * master control.  A follower may have either one or two channels.
+ */
+
+struct link_follower {
+	struct list_head list;
+	struct link_master *master;
+	struct link_ctl_info info;
+	int vals[2];		/* current values */
+	unsigned int flags;
+	struct snd_kcontrol *kctl; /* original kcontrol pointer */
+	struct snd_kcontrol follower; /* the copy of original control entry */
+};
+
+static int follower_update(struct link_follower *follower)
+{
+	struct snd_ctl_elem_value *uctl;
+	int err, ch;
+
+	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
+	if (!uctl)
+		return -ENOMEM;
+	uctl->id = follower->follower.id;
+	err = follower->follower.get(&follower->follower, uctl);
+	if (err < 0)
+		goto error;
+	for (ch = 0; ch < follower->info.count; ch++)
+		follower->vals[ch] = uctl->value.integer.value[ch];
+ error:
+	kfree(uctl);
+	return err < 0 ? err : 0;
+}
+
+/* get the follower ctl info and save the initial values */
+static int follower_init(struct link_follower *follower)
+{
+	struct snd_ctl_elem_info *uinfo;
+	int err;
+
+	if (follower->info.count) {
+		/* already initialized */
+		if (follower->flags & SND_CTL_FOLLOWER_NEED_UPDATE)
+			return follower_update(follower);
+		return 0;
+	}
+
+	uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
+	if (!uinfo)
+		return -ENOMEM;
+	uinfo->id = follower->follower.id;
+	err = follower->follower.info(&follower->follower, uinfo);
+	if (err < 0) {
+		kfree(uinfo);
+		return err;
+	}
+	follower->info.type = uinfo->type;
+	follower->info.count = uinfo->count;
+	if (follower->info.count > 2  ||
+	    (follower->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
+	     follower->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
+		pr_err("ALSA: vmaster: invalid follower element\n");
+		kfree(uinfo);
+		return -EINVAL;
+	}
+	follower->info.min_val = uinfo->value.integer.min;
+	follower->info.max_val = uinfo->value.integer.max;
+	kfree(uinfo);
+
+	return follower_update(follower);
+}
+
+/* initialize master volume */
+static int master_init(struct link_master *master)
+{
+	struct link_follower *follower;
+
+	if (master->info.count)
+		return 0; /* already initialized */
+
+	list_for_each_entry(follower, &master->followers, list) {
+		int err = follower_init(follower);
+		if (err < 0)
+			return err;
+		master->info = follower->info;
+		master->info.count = 1; /* always mono */
+		/* set full volume as default (= no attenuation) */
+		master->val = master->info.max_val;
+		if (master->hook)
+			master->hook(master->hook_private_data, master->val);
+		return 1;
+	}
+	return -ENOENT;
+}
+
+static int follower_get_val(struct link_follower *follower,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	int err, ch;
+
+	err = follower_init(follower);
+	if (err < 0)
+		return err;
+	for (ch = 0; ch < follower->info.count; ch++)
+		ucontrol->value.integer.value[ch] = follower->vals[ch];
+	return 0;
+}
+
+static int follower_put_val(struct link_follower *follower,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	int err, ch, vol;
+
+	err = master_init(follower->master);
+	if (err < 0)
+		return err;
+
+	switch (follower->info.type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+		for (ch = 0; ch < follower->info.count; ch++)
+			ucontrol->value.integer.value[ch] &=
+				!!follower->master->val;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		for (ch = 0; ch < follower->info.count; ch++) {
+			/* max master volume is supposed to be 0 dB */
+			vol = ucontrol->value.integer.value[ch];
+			vol += follower->master->val - follower->master->info.max_val;
+			if (vol < follower->info.min_val)
+				vol = follower->info.min_val;
+			else if (vol > follower->info.max_val)
+				vol = follower->info.max_val;
+			ucontrol->value.integer.value[ch] = vol;
+		}
+		break;
+	}
+	return follower->follower.put(&follower->follower, ucontrol);
+}
+
+/*
+ * ctl callbacks for followers
+ */
+static int follower_info(struct snd_kcontrol *kcontrol,
+			 struct snd_ctl_elem_info *uinfo)
+{
+	struct link_follower *follower = snd_kcontrol_chip(kcontrol);
+	return follower->follower.info(&follower->follower, uinfo);
+}
+
+static int follower_get(struct snd_kcontrol *kcontrol,
+			struct snd_ctl_elem_value *ucontrol)
+{
+	struct link_follower *follower = snd_kcontrol_chip(kcontrol);
+	return follower_get_val(follower, ucontrol);
+}
+
+static int follower_put(struct snd_kcontrol *kcontrol,
+			struct snd_ctl_elem_value *ucontrol)
+{
+	struct link_follower *follower = snd_kcontrol_chip(kcontrol);
+	int err, ch, changed = 0;
+
+	err = follower_init(follower);
+	if (err < 0)
+		return err;
+	for (ch = 0; ch < follower->info.count; ch++) {
+		if (follower->vals[ch] != ucontrol->value.integer.value[ch]) {
+			changed = 1;
+			follower->vals[ch] = ucontrol->value.integer.value[ch];
+		}
+	}
+	if (!changed)
+		return 0;
+	err = follower_put_val(follower, ucontrol);
+	if (err < 0)
+		return err;
+	return 1;
+}
+
+static int follower_tlv_cmd(struct snd_kcontrol *kcontrol,
+			    int op_flag, unsigned int size,
+			    unsigned int __user *tlv)
+{
+	struct link_follower *follower = snd_kcontrol_chip(kcontrol);
+	/* FIXME: this assumes that the max volume is 0 dB */
+	return follower->follower.tlv.c(&follower->follower, op_flag, size, tlv);
+}
+
+static void follower_free(struct snd_kcontrol *kcontrol)
+{
+	struct link_follower *follower = snd_kcontrol_chip(kcontrol);
+	if (follower->follower.private_free)
+		follower->follower.private_free(&follower->follower);
+	if (follower->master)
+		list_del(&follower->list);
+	kfree(follower);
+}
+
+/*
+ * Add a follower control to the group with the given master control
+ *
+ * All followers must be the same type (returning the same information
+ * via info callback).  The function doesn't check it, so it's your
+ * responsibility.
+ *
+ * Also, some additional limitations:
+ * - at most two channels
+ * - logarithmic volume control (dB level), no linear volume
+ * - master can only attenuate the volume, no gain
+ */
+int _snd_ctl_add_follower(struct snd_kcontrol *master,
+			  struct snd_kcontrol *follower,
+			  unsigned int flags)
+{
+	struct link_master *master_link = snd_kcontrol_chip(master);
+	struct link_follower *srec;
+
+	srec = kzalloc(struct_size(srec, follower.vd, follower->count),
+		       GFP_KERNEL);
+	if (!srec)
+		return -ENOMEM;
+	srec->kctl = follower;
+	srec->follower = *follower;
+	memcpy(srec->follower.vd, follower->vd, follower->count * sizeof(*follower->vd));
+	srec->master = master_link;
+	srec->flags = flags;
+
+	/* override callbacks */
+	follower->info = follower_info;
+	follower->get = follower_get;
+	follower->put = follower_put;
+	if (follower->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
+		follower->tlv.c = follower_tlv_cmd;
+	follower->private_data = srec;
+	follower->private_free = follower_free;
+
+	list_add_tail(&srec->list, &master_link->followers);
+	return 0;
+}
+EXPORT_SYMBOL(_snd_ctl_add_follower);
+
+/**
+ * snd_ctl_add_followers - add multiple followers to vmaster
+ * @card: card instance
+ * @master: the target vmaster kcontrol object
+ * @list: NULL-terminated list of name strings of followers to be added
+ *
+ * Adds the multiple follower kcontrols with the given names.
+ * Returns 0 for success or a negative error code.
+ */
+int snd_ctl_add_followers(struct snd_card *card, struct snd_kcontrol *master,
+			  const char * const *list)
+{
+	struct snd_kcontrol *follower;
+	int err;
+
+	for (; *list; list++) {
+		follower = snd_ctl_find_id_mixer(card, *list);
+		if (follower) {
+			err = snd_ctl_add_follower(master, follower);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_add_followers);
+
+/*
+ * ctl callbacks for master controls
+ */
+static int master_info(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_info *uinfo)
+{
+	struct link_master *master = snd_kcontrol_chip(kcontrol);
+	int ret;
+
+	ret = master_init(master);
+	if (ret < 0)
+		return ret;
+	uinfo->type = master->info.type;
+	uinfo->count = master->info.count;
+	uinfo->value.integer.min = master->info.min_val;
+	uinfo->value.integer.max = master->info.max_val;
+	return 0;
+}
+
+static int master_get(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_value *ucontrol)
+{
+	struct link_master *master = snd_kcontrol_chip(kcontrol);
+	int err = master_init(master);
+	if (err < 0)
+		return err;
+	ucontrol->value.integer.value[0] = master->val;
+	return 0;
+}
+
+static int sync_followers(struct link_master *master, int old_val, int new_val)
+{
+	struct link_follower *follower;
+	struct snd_ctl_elem_value *uval;
+
+	uval = kmalloc(sizeof(*uval), GFP_KERNEL);
+	if (!uval)
+		return -ENOMEM;
+	list_for_each_entry(follower, &master->followers, list) {
+		master->val = old_val;
+		uval->id = follower->follower.id;
+		follower_get_val(follower, uval);
+		master->val = new_val;
+		follower_put_val(follower, uval);
+	}
+	kfree(uval);
+	return 0;
+}
+
+static int master_put(struct snd_kcontrol *kcontrol,
+		      struct snd_ctl_elem_value *ucontrol)
+{
+	struct link_master *master = snd_kcontrol_chip(kcontrol);
+	int err, new_val, old_val;
+	bool first_init;
+
+	err = master_init(master);
+	if (err < 0)
+		return err;
+	first_init = err;
+	old_val = master->val;
+	new_val = ucontrol->value.integer.value[0];
+	if (new_val == old_val)
+		return 0;
+
+	err = sync_followers(master, old_val, new_val);
+	if (err < 0)
+		return err;
+	if (master->hook && !first_init)
+		master->hook(master->hook_private_data, master->val);
+	return 1;
+}
+
+static void master_free(struct snd_kcontrol *kcontrol)
+{
+	struct link_master *master = snd_kcontrol_chip(kcontrol);
+	struct link_follower *follower, *n;
+
+	/* free all follower links and retore the original follower kctls */
+	list_for_each_entry_safe(follower, n, &master->followers, list) {
+		struct snd_kcontrol *sctl = follower->kctl;
+		struct list_head olist = sctl->list;
+		memcpy(sctl, &follower->follower, sizeof(*sctl));
+		memcpy(sctl->vd, follower->follower.vd,
+		       sctl->count * sizeof(*sctl->vd));
+		sctl->list = olist; /* keep the current linked-list */
+		kfree(follower);
+	}
+	kfree(master);
+}
+
+
+/**
+ * snd_ctl_make_virtual_master - Create a virtual master control
+ * @name: name string of the control element to create
+ * @tlv: optional TLV int array for dB information
+ *
+ * Creates a virtual master control with the given name string.
+ *
+ * After creating a vmaster element, you can add the follower controls
+ * via snd_ctl_add_follower() or snd_ctl_add_follower_uncached().
+ *
+ * The optional argument @tlv can be used to specify the TLV information
+ * for dB scale of the master control.  It should be a single element
+ * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
+ * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
+ *
+ * Return: The created control element, or %NULL for errors (ENOMEM).
+ */
+struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
+						 const unsigned int *tlv)
+{
+	struct link_master *master;
+	struct snd_kcontrol *kctl;
+	struct snd_kcontrol_new knew;
+
+	memset(&knew, 0, sizeof(knew));
+	knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+	knew.name = name;
+	knew.info = master_info;
+
+	master = kzalloc(sizeof(*master), GFP_KERNEL);
+	if (!master)
+		return NULL;
+	INIT_LIST_HEAD(&master->followers);
+
+	kctl = snd_ctl_new1(&knew, master);
+	if (!kctl) {
+		kfree(master);
+		return NULL;
+	}
+	/* override some callbacks */
+	kctl->info = master_info;
+	kctl->get = master_get;
+	kctl->put = master_put;
+	kctl->private_free = master_free;
+
+	/* additional (constant) TLV read */
+	if (tlv) {
+		unsigned int type = tlv[SNDRV_CTL_TLVO_TYPE];
+		if (type == SNDRV_CTL_TLVT_DB_SCALE ||
+		    type == SNDRV_CTL_TLVT_DB_MINMAX ||
+		    type == SNDRV_CTL_TLVT_DB_MINMAX_MUTE) {
+			kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
+			memcpy(master->tlv, tlv, sizeof(master->tlv));
+			kctl->tlv.p = master->tlv;
+		}
+	}
+
+	return kctl;
+}
+EXPORT_SYMBOL(snd_ctl_make_virtual_master);
+
+/**
+ * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
+ * @kcontrol: vmaster kctl element
+ * @hook: the hook function
+ * @private_data: the private_data pointer to be saved
+ *
+ * Adds the given hook to the vmaster control element so that it's called
+ * at each time when the value is changed.
+ *
+ * Return: Zero.
+ */
+int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
+			     void (*hook)(void *private_data, int),
+			     void *private_data)
+{
+	struct link_master *master = snd_kcontrol_chip(kcontrol);
+	master->hook = hook;
+	master->hook_private_data = private_data;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);
+
+/**
+ * snd_ctl_sync_vmaster - Sync the vmaster followers and hook
+ * @kcontrol: vmaster kctl element
+ * @hook_only: sync only the hook
+ *
+ * Forcibly call the put callback of each follower and call the hook function
+ * to synchronize with the current value of the given vmaster element.
+ * NOP when NULL is passed to @kcontrol.
+ */
+void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
+{
+	struct link_master *master;
+	bool first_init = false;
+
+	if (!kcontrol)
+		return;
+	master = snd_kcontrol_chip(kcontrol);
+	if (!hook_only) {
+		int err = master_init(master);
+		if (err < 0)
+			return;
+		first_init = err;
+		err = sync_followers(master, master->val, master->val);
+		if (err < 0)
+			return;
+	}
+
+	if (master->hook && !first_init)
+		master->hook(master->hook_private_data, master->val);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);
+
+/**
+ * snd_ctl_apply_vmaster_followers - Apply function to each vmaster follower
+ * @kctl: vmaster kctl element
+ * @func: function to apply
+ * @arg: optional function argument
+ *
+ * Apply the function @func to each follower kctl of the given vmaster kctl.
+ *
+ * Return: 0 if successful, or a negative error code
+ */
+int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
+				    int (*func)(struct snd_kcontrol *vfollower,
+						struct snd_kcontrol *follower,
+						void *arg),
+				    void *arg)
+{
+	struct link_master *master;
+	struct link_follower *follower;
+	int err;
+
+	master = snd_kcontrol_chip(kctl);
+	err = master_init(master);
+	if (err < 0)
+		return err;
+	list_for_each_entry(follower, &master->followers, list) {
+		err = func(follower->kctl, &follower->follower, arg);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_apply_vmaster_followers);