ALSA: rawmidi: UMP support

This patch adds the support helpers for UMP (Universal MIDI Packet) in
ALSA core.

The basic design is that a rawmidi instance is assigned to each UMP
Endpoint.  A UMP Endpoint provides a UMP stream, typically
bidirectional (but can be also uni-directional, too), which may hold
up to 16 UMP Groups, where each UMP (input/output) Group corresponds
to the traditional MIDI I/O Endpoint.

Additionally, the ALSA UMP abstraction provides the multiple UMP
Blocks that can be assigned to each UMP Endpoint.  A UMP Block is a
metadata to hold the UMP Group clusters, and can represent the
functions assigned to each UMP Group.  A typical implementation of UMP
Block is the Group Terminal Blocks of USB MIDI 2.0 specification.

For distinguishing from the legacy byte-stream MIDI device, a new
device "umpC*D*" will be created, instead of the standard (MIDI 1.0)
devices "midiC*D*".  The UMP instance can be identified by the new
rawmidi info bit SNDRV_RAWMIDI_INFO_UMP, too.

A UMP rawmidi device reads/writes only in 4-bytes words alignment,
stored in CPU native endianness.

The transmit and receive functions take care of the input/out data
alignment, and may return zero or aligned size, and the params ioctl
may return -EINVAL when the given input/output buffer size isn't
aligned.

A few new UMP-specific ioctls are added for obtaining the new UMP
endpoint and block information.

As of this commit, no ALSA sequencer instance is attached to UMP
devices yet.  They will be supported by later patches.

Along with those changes, the protocol version for rawmidi is bumped
to 2.0.3.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

5 files changed, 339 insertions, 40 deletions

diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index 12990d9a4dffe..eb1c6c930de93 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -26,6 +26,10 @@ config SND_RAWMIDI
 	tristate
 	select SND_SEQ_DEVICE if SND_SEQUENCER != n
 
+config SND_UMP
+	tristate
+	select SND_RAWMIDI
+
 config SND_COMPRESS_OFFLOAD
 	tristate
 
diff --git a/sound/core/Makefile b/sound/core/Makefile
index 2762f03d9b7bc..562a05edbc50a 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile
@@ -28,6 +28,7 @@ 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-timer-objs    := timer.o
 snd-hrtimer-objs  := hrtimer.o
 snd-rtctimer-objs := rtctimer.o
@@ -45,6 +46,7 @@ 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/
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index ab28cfc1fac85..6360e2239a63f 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -21,6 +21,7 @@
 #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.");
@@ -35,7 +36,6 @@ 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_free(struct snd_rawmidi *rmidi);
 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);
@@ -73,6 +73,9 @@ struct snd_rawmidi_status64 {
 
 #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;
@@ -181,9 +184,23 @@ static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
 	}
 	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;
@@ -721,6 +738,8 @@ static int resize_runtime_buffer(struct snd_rawmidi_substream *substream,
 		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)
@@ -1046,12 +1065,13 @@ static int receive_with_tstamp_framing(struct snd_rawmidi_substream *substream,
 	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 > 0) {
+	while (src_count > align) {
 		if ((int)(runtime->buffer_size - runtime->avail) < frame_size) {
 			runtime->xruns += src_count;
 			break;
@@ -1059,7 +1079,9 @@ static int receive_with_tstamp_framing(struct snd_rawmidi_substream *substream,
 		if (src_count >= SNDRV_RAWMIDI_FRAMING_DATA_LENGTH)
 			frame.length = SNDRV_RAWMIDI_FRAMING_DATA_LENGTH;
 		else {
-			frame.length = src_count;
+			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);
@@ -1123,6 +1145,10 @@ int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
 		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 */
@@ -1142,6 +1168,9 @@ int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
 			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;
@@ -1342,12 +1371,18 @@ static int __snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
 			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;
 		}
@@ -1404,6 +1439,7 @@ static int __snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream,
 		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;
@@ -1690,6 +1726,9 @@ static void snd_rawmidi_proc_info_read(struct snd_info_entry *entry,
 
 	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");
 	mutex_lock(&rmidi->open_mutex);
 	if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT) {
 		list_for_each_entry(substream,
@@ -1800,25 +1839,12 @@ static void release_rawmidi_device(struct device *dev)
 	kfree(container_of(dev, struct snd_rawmidi, dev));
 }
 
-/**
- * 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)
+/* 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)
 {
-	struct snd_rawmidi *rmidi;
 	int err;
 	static const struct snd_device_ops ops = {
 		.dev_free = snd_rawmidi_dev_free,
@@ -1826,50 +1852,78 @@ int snd_rawmidi_new(struct snd_card *card, char *id, int device,
 		.dev_disconnect = snd_rawmidi_dev_disconnect,
 	};
 
-	if (snd_BUG_ON(!card))
-		return -ENXIO;
-	if (rrawmidi)
-		*rrawmidi = NULL;
-	rmidi = kzalloc(sizeof(*rmidi), GFP_KERNEL);
-	if (!rmidi)
-		return -ENOMEM;
 	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));
 
 	snd_device_initialize(&rmidi->dev, card);
 	rmidi->dev.release = release_rawmidi_device;
-	dev_set_name(&rmidi->dev, "midiC%iD%i", card->number, device);
+	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)
-		goto error;
+		return err;
 	err = snd_rawmidi_alloc_substreams(rmidi,
 					   &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT],
 					   SNDRV_RAWMIDI_STREAM_OUTPUT,
 					   output_count);
 	if (err < 0)
-		goto error;
+		return err;
 	err = snd_device_new(card, SNDRV_DEV_RAWMIDI, rmidi, &ops);
 	if (err < 0)
-		goto error;
+		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;
-
- error:
-	snd_rawmidi_free(rmidi);
-	return err;
 }
 EXPORT_SYMBOL(snd_rawmidi_new);
 
@@ -1884,7 +1938,8 @@ static void snd_rawmidi_free_substreams(struct snd_rawmidi_str *stream)
 	}
 }
 
-static int snd_rawmidi_free(struct snd_rawmidi *rmidi)
+/* called from ump.c, too */
+int snd_rawmidi_free(struct snd_rawmidi *rmidi)
 {
 	if (!rmidi)
 		return 0;
@@ -1901,6 +1956,7 @@ static int snd_rawmidi_free(struct snd_rawmidi *rmidi)
 	put_device(&rmidi->dev);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(snd_rawmidi_free);
 
 static int snd_rawmidi_dev_free(struct snd_device *device)
 {
@@ -1951,7 +2007,8 @@ static int snd_rawmidi_dev_register(struct snd_device *device)
 	}
 #ifdef CONFIG_SND_OSSEMUL
 	rmidi->ossreg = 0;
-	if ((int)rmidi->device == midi_map[rmidi->card->number]) {
+	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) {
@@ -1965,7 +2022,8 @@ static int snd_rawmidi_dev_register(struct snd_device *device)
 #endif
 		}
 	}
-	if ((int)rmidi->device == amidi_map[rmidi->card->number]) {
+	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) {
@@ -1989,7 +2047,8 @@ static int snd_rawmidi_dev_register(struct snd_device *device)
 	}
 	rmidi->proc_entry = entry;
 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
-	if (!rmidi->ops || !rmidi->ops->dev_register) { /* own registration mechanism */
+	/* 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;
diff --git a/sound/core/rawmidi_compat.c b/sound/core/rawmidi_compat.c
index 68a93443583c2..b81b30d82f882 100644
--- a/sound/core/rawmidi_compat.c
+++ b/sound/core/rawmidi_compat.c
@@ -111,6 +111,10 @@ static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsign
 	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);
diff --git a/sound/core/ump.c b/sound/core/ump.c
new file mode 100644
index 0000000000000..ee57ba1ee9892
--- /dev/null
+++ b/sound/core/ump.c
@@ -0,0 +1,230 @@
+// 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>
+
+#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 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,
+};
+
+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);
+}
+
+/**
+ * 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);
+	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;
+
+	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
+ */
+static int snd_ump_dev_register(struct snd_rawmidi *rmidi)
+{
+	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;
+}
+
+/**
+ * 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;
+	}
+}
+
+MODULE_DESCRIPTION("Universal MIDI Packet (UMP) Core Driver");
+MODULE_LICENSE("GPL");