Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 2527 insertions, 0 deletions

diff --git a/sound/usb/midi.c b/sound/usb/midi.c
new file mode 100644
index 000000000..b02e1a333
--- /dev/null
+++ b/sound/usb/midi.c
@@ -0,0 +1,2527 @@
+/*
+ * usbmidi.c - ALSA USB MIDI driver
+ *
+ * Copyright (c) 2002-2009 Clemens Ladisch
+ * All rights reserved.
+ *
+ * Based on the OSS usb-midi driver by NAGANO Daisuke,
+ *          NetBSD's umidi driver by Takuya SHIOZAKI,
+ *          the "USB Device Class Definition for MIDI Devices" by Roland
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed and/or modified under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/usb.h>
+#include <linux/wait.h>
+#include <linux/usb/audio.h>
+#include <linux/module.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/rawmidi.h>
+#include <sound/asequencer.h>
+#include "usbaudio.h"
+#include "midi.h"
+#include "power.h"
+#include "helper.h"
+
+/*
+ * define this to log all USB packets
+ */
+/* #define DUMP_PACKETS */
+
+/*
+ * how long to wait after some USB errors, so that hub_wq can disconnect() us
+ * without too many spurious errors
+ */
+#define ERROR_DELAY_JIFFIES (HZ / 10)
+
+#define OUTPUT_URBS 7
+#define INPUT_URBS 7
+
+
+MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
+MODULE_DESCRIPTION("USB Audio/MIDI helper module");
+MODULE_LICENSE("Dual BSD/GPL");
+
+
+struct usb_ms_header_descriptor {
+	__u8  bLength;
+	__u8  bDescriptorType;
+	__u8  bDescriptorSubtype;
+	__u8  bcdMSC[2];
+	__le16 wTotalLength;
+} __attribute__ ((packed));
+
+struct usb_ms_endpoint_descriptor {
+	__u8  bLength;
+	__u8  bDescriptorType;
+	__u8  bDescriptorSubtype;
+	__u8  bNumEmbMIDIJack;
+	__u8  baAssocJackID[];
+} __attribute__ ((packed));
+
+struct snd_usb_midi_in_endpoint;
+struct snd_usb_midi_out_endpoint;
+struct snd_usb_midi_endpoint;
+
+struct usb_protocol_ops {
+	void (*input)(struct snd_usb_midi_in_endpoint*, uint8_t*, int);
+	void (*output)(struct snd_usb_midi_out_endpoint *ep, struct urb *urb);
+	void (*output_packet)(struct urb*, uint8_t, uint8_t, uint8_t, uint8_t);
+	void (*init_out_endpoint)(struct snd_usb_midi_out_endpoint *);
+	void (*finish_out_endpoint)(struct snd_usb_midi_out_endpoint *);
+};
+
+struct snd_usb_midi {
+	struct usb_device *dev;
+	struct snd_card *card;
+	struct usb_interface *iface;
+	const struct snd_usb_audio_quirk *quirk;
+	struct snd_rawmidi *rmidi;
+	const struct usb_protocol_ops *usb_protocol_ops;
+	struct list_head list;
+	struct timer_list error_timer;
+	spinlock_t disc_lock;
+	struct rw_semaphore disc_rwsem;
+	struct mutex mutex;
+	u32 usb_id;
+	int next_midi_device;
+
+	struct snd_usb_midi_endpoint {
+		struct snd_usb_midi_out_endpoint *out;
+		struct snd_usb_midi_in_endpoint *in;
+	} endpoints[MIDI_MAX_ENDPOINTS];
+	unsigned long input_triggered;
+	unsigned int opened[2];
+	unsigned char disconnected;
+	unsigned char input_running;
+
+	struct snd_kcontrol *roland_load_ctl;
+};
+
+struct snd_usb_midi_out_endpoint {
+	struct snd_usb_midi *umidi;
+	struct out_urb_context {
+		struct urb *urb;
+		struct snd_usb_midi_out_endpoint *ep;
+	} urbs[OUTPUT_URBS];
+	unsigned int active_urbs;
+	unsigned int drain_urbs;
+	int max_transfer;		/* size of urb buffer */
+	struct work_struct work;
+	unsigned int next_urb;
+	spinlock_t buffer_lock;
+
+	struct usbmidi_out_port {
+		struct snd_usb_midi_out_endpoint *ep;
+		struct snd_rawmidi_substream *substream;
+		int active;
+		uint8_t cable;		/* cable number << 4 */
+		uint8_t state;
+#define STATE_UNKNOWN	0
+#define STATE_1PARAM	1
+#define STATE_2PARAM_1	2
+#define STATE_2PARAM_2	3
+#define STATE_SYSEX_0	4
+#define STATE_SYSEX_1	5
+#define STATE_SYSEX_2	6
+		uint8_t data[2];
+	} ports[0x10];
+	int current_port;
+
+	wait_queue_head_t drain_wait;
+};
+
+struct snd_usb_midi_in_endpoint {
+	struct snd_usb_midi *umidi;
+	struct urb *urbs[INPUT_URBS];
+	struct usbmidi_in_port {
+		struct snd_rawmidi_substream *substream;
+		u8 running_status_length;
+	} ports[0x10];
+	u8 seen_f5;
+	bool in_sysex;
+	u8 last_cin;
+	u8 error_resubmit;
+	int current_port;
+};
+
+static void snd_usbmidi_do_output(struct snd_usb_midi_out_endpoint *ep);
+
+static const uint8_t snd_usbmidi_cin_length[] = {
+	0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
+};
+
+/*
+ * Submits the URB, with error handling.
+ */
+static int snd_usbmidi_submit_urb(struct urb *urb, gfp_t flags)
+{
+	int err = usb_submit_urb(urb, flags);
+	if (err < 0 && err != -ENODEV)
+		dev_err(&urb->dev->dev, "usb_submit_urb: %d\n", err);
+	return err;
+}
+
+/*
+ * Error handling for URB completion functions.
+ */
+static int snd_usbmidi_urb_error(const struct urb *urb)
+{
+	switch (urb->status) {
+	/* manually unlinked, or device gone */
+	case -ENOENT:
+	case -ECONNRESET:
+	case -ESHUTDOWN:
+	case -ENODEV:
+		return -ENODEV;
+	/* errors that might occur during unplugging */
+	case -EPROTO:
+	case -ETIME:
+	case -EILSEQ:
+		return -EIO;
+	default:
+		dev_err(&urb->dev->dev, "urb status %d\n", urb->status);
+		return 0; /* continue */
+	}
+}
+
+/*
+ * Receives a chunk of MIDI data.
+ */
+static void snd_usbmidi_input_data(struct snd_usb_midi_in_endpoint *ep,
+				   int portidx, uint8_t *data, int length)
+{
+	struct usbmidi_in_port *port = &ep->ports[portidx];
+
+	if (!port->substream) {
+		dev_dbg(&ep->umidi->dev->dev, "unexpected port %d!\n", portidx);
+		return;
+	}
+	if (!test_bit(port->substream->number, &ep->umidi->input_triggered))
+		return;
+	snd_rawmidi_receive(port->substream, data, length);
+}
+
+#ifdef DUMP_PACKETS
+static void dump_urb(const char *type, const u8 *data, int length)
+{
+	snd_printk(KERN_DEBUG "%s packet: [", type);
+	for (; length > 0; ++data, --length)
+		printk(KERN_CONT " %02x", *data);
+	printk(KERN_CONT " ]\n");
+}
+#else
+#define dump_urb(type, data, length) /* nothing */
+#endif
+
+/*
+ * Processes the data read from the device.
+ */
+static void snd_usbmidi_in_urb_complete(struct urb *urb)
+{
+	struct snd_usb_midi_in_endpoint *ep = urb->context;
+
+	if (urb->status == 0) {
+		dump_urb("received", urb->transfer_buffer, urb->actual_length);
+		ep->umidi->usb_protocol_ops->input(ep, urb->transfer_buffer,
+						   urb->actual_length);
+	} else {
+		int err = snd_usbmidi_urb_error(urb);
+		if (err < 0) {
+			if (err != -ENODEV) {
+				ep->error_resubmit = 1;
+				mod_timer(&ep->umidi->error_timer,
+					  jiffies + ERROR_DELAY_JIFFIES);
+			}
+			return;
+		}
+	}
+
+	urb->dev = ep->umidi->dev;
+	snd_usbmidi_submit_urb(urb, GFP_ATOMIC);
+}
+
+static void snd_usbmidi_out_urb_complete(struct urb *urb)
+{
+	struct out_urb_context *context = urb->context;
+	struct snd_usb_midi_out_endpoint *ep = context->ep;
+	unsigned int urb_index;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ep->buffer_lock, flags);
+	urb_index = context - ep->urbs;
+	ep->active_urbs &= ~(1 << urb_index);
+	if (unlikely(ep->drain_urbs)) {
+		ep->drain_urbs &= ~(1 << urb_index);
+		wake_up(&ep->drain_wait);
+	}
+	spin_unlock_irqrestore(&ep->buffer_lock, flags);
+	if (urb->status < 0) {
+		int err = snd_usbmidi_urb_error(urb);
+		if (err < 0) {
+			if (err != -ENODEV)
+				mod_timer(&ep->umidi->error_timer,
+					  jiffies + ERROR_DELAY_JIFFIES);
+			return;
+		}
+	}
+	snd_usbmidi_do_output(ep);
+}
+
+/*
+ * This is called when some data should be transferred to the device
+ * (from one or more substreams).
+ */
+static void snd_usbmidi_do_output(struct snd_usb_midi_out_endpoint *ep)
+{
+	unsigned int urb_index;
+	struct urb *urb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ep->buffer_lock, flags);
+	if (ep->umidi->disconnected) {
+		spin_unlock_irqrestore(&ep->buffer_lock, flags);
+		return;
+	}
+
+	urb_index = ep->next_urb;
+	for (;;) {
+		if (!(ep->active_urbs & (1 << urb_index))) {
+			urb = ep->urbs[urb_index].urb;
+			urb->transfer_buffer_length = 0;
+			ep->umidi->usb_protocol_ops->output(ep, urb);
+			if (urb->transfer_buffer_length == 0)
+				break;
+
+			dump_urb("sending", urb->transfer_buffer,
+				 urb->transfer_buffer_length);
+			urb->dev = ep->umidi->dev;
+			if (snd_usbmidi_submit_urb(urb, GFP_ATOMIC) < 0)
+				break;
+			ep->active_urbs |= 1 << urb_index;
+		}
+		if (++urb_index >= OUTPUT_URBS)
+			urb_index = 0;
+		if (urb_index == ep->next_urb)
+			break;
+	}
+	ep->next_urb = urb_index;
+	spin_unlock_irqrestore(&ep->buffer_lock, flags);
+}
+
+static void snd_usbmidi_out_work(struct work_struct *work)
+{
+	struct snd_usb_midi_out_endpoint *ep =
+		container_of(work, struct snd_usb_midi_out_endpoint, work);
+
+	snd_usbmidi_do_output(ep);
+}
+
+/* called after transfers had been interrupted due to some USB error */
+static void snd_usbmidi_error_timer(struct timer_list *t)
+{
+	struct snd_usb_midi *umidi = from_timer(umidi, t, error_timer);
+	unsigned int i, j;
+
+	spin_lock(&umidi->disc_lock);
+	if (umidi->disconnected) {
+		spin_unlock(&umidi->disc_lock);
+		return;
+	}
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		struct snd_usb_midi_in_endpoint *in = umidi->endpoints[i].in;
+		if (in && in->error_resubmit) {
+			in->error_resubmit = 0;
+			for (j = 0; j < INPUT_URBS; ++j) {
+				if (atomic_read(&in->urbs[j]->use_count))
+					continue;
+				in->urbs[j]->dev = umidi->dev;
+				snd_usbmidi_submit_urb(in->urbs[j], GFP_ATOMIC);
+			}
+		}
+		if (umidi->endpoints[i].out)
+			snd_usbmidi_do_output(umidi->endpoints[i].out);
+	}
+	spin_unlock(&umidi->disc_lock);
+}
+
+/* helper function to send static data that may not DMA-able */
+static int send_bulk_static_data(struct snd_usb_midi_out_endpoint *ep,
+				 const void *data, int len)
+{
+	int err = 0;
+	void *buf = kmemdup(data, len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	dump_urb("sending", buf, len);
+	if (ep->urbs[0].urb)
+		err = usb_bulk_msg(ep->umidi->dev, ep->urbs[0].urb->pipe,
+				   buf, len, NULL, 250);
+	kfree(buf);
+	return err;
+}
+
+/*
+ * Standard USB MIDI protocol: see the spec.
+ * Midiman protocol: like the standard protocol, but the control byte is the
+ * fourth byte in each packet, and uses length instead of CIN.
+ */
+
+static void snd_usbmidi_standard_input(struct snd_usb_midi_in_endpoint *ep,
+				       uint8_t *buffer, int buffer_length)
+{
+	int i;
+
+	for (i = 0; i + 3 < buffer_length; i += 4)
+		if (buffer[i] != 0) {
+			int cable = buffer[i] >> 4;
+			int length = snd_usbmidi_cin_length[buffer[i] & 0x0f];
+			snd_usbmidi_input_data(ep, cable, &buffer[i + 1],
+					       length);
+		}
+}
+
+static void snd_usbmidi_midiman_input(struct snd_usb_midi_in_endpoint *ep,
+				      uint8_t *buffer, int buffer_length)
+{
+	int i;
+
+	for (i = 0; i + 3 < buffer_length; i += 4)
+		if (buffer[i + 3] != 0) {
+			int port = buffer[i + 3] >> 4;
+			int length = buffer[i + 3] & 3;
+			snd_usbmidi_input_data(ep, port, &buffer[i], length);
+		}
+}
+
+/*
+ * Buggy M-Audio device: running status on input results in a packet that has
+ * the data bytes but not the status byte and that is marked with CIN 4.
+ */
+static void snd_usbmidi_maudio_broken_running_status_input(
+					struct snd_usb_midi_in_endpoint *ep,
+					uint8_t *buffer, int buffer_length)
+{
+	int i;
+
+	for (i = 0; i + 3 < buffer_length; i += 4)
+		if (buffer[i] != 0) {
+			int cable = buffer[i] >> 4;
+			u8 cin = buffer[i] & 0x0f;
+			struct usbmidi_in_port *port = &ep->ports[cable];
+			int length;
+
+			length = snd_usbmidi_cin_length[cin];
+			if (cin == 0xf && buffer[i + 1] >= 0xf8)
+				; /* realtime msg: no running status change */
+			else if (cin >= 0x8 && cin <= 0xe)
+				/* channel msg */
+				port->running_status_length = length - 1;
+			else if (cin == 0x4 &&
+				 port->running_status_length != 0 &&
+				 buffer[i + 1] < 0x80)
+				/* CIN 4 that is not a SysEx */
+				length = port->running_status_length;
+			else
+				/*
+				 * All other msgs cannot begin running status.
+				 * (A channel msg sent as two or three CIN 0xF
+				 * packets could in theory, but this device
+				 * doesn't use this format.)
+				 */
+				port->running_status_length = 0;
+			snd_usbmidi_input_data(ep, cable, &buffer[i + 1],
+					       length);
+		}
+}
+
+/*
+ * QinHeng CH345 is buggy: every second packet inside a SysEx has not CIN 4
+ * but the previously seen CIN, but still with three data bytes.
+ */
+static void ch345_broken_sysex_input(struct snd_usb_midi_in_endpoint *ep,
+				     uint8_t *buffer, int buffer_length)
+{
+	unsigned int i, cin, length;
+
+	for (i = 0; i + 3 < buffer_length; i += 4) {
+		if (buffer[i] == 0 && i > 0)
+			break;
+		cin = buffer[i] & 0x0f;
+		if (ep->in_sysex &&
+		    cin == ep->last_cin &&
+		    (buffer[i + 1 + (cin == 0x6)] & 0x80) == 0)
+			cin = 0x4;
+#if 0
+		if (buffer[i + 1] == 0x90) {
+			/*
+			 * Either a corrupted running status or a real note-on
+			 * message; impossible to detect reliably.
+			 */
+		}
+#endif
+		length = snd_usbmidi_cin_length[cin];
+		snd_usbmidi_input_data(ep, 0, &buffer[i + 1], length);
+		ep->in_sysex = cin == 0x4;
+		if (!ep->in_sysex)
+			ep->last_cin = cin;
+	}
+}
+
+/*
+ * CME protocol: like the standard protocol, but SysEx commands are sent as a
+ * single USB packet preceded by a 0x0F byte.
+ */
+static void snd_usbmidi_cme_input(struct snd_usb_midi_in_endpoint *ep,
+				  uint8_t *buffer, int buffer_length)
+{
+	if (buffer_length < 2 || (buffer[0] & 0x0f) != 0x0f)
+		snd_usbmidi_standard_input(ep, buffer, buffer_length);
+	else
+		snd_usbmidi_input_data(ep, buffer[0] >> 4,
+				       &buffer[1], buffer_length - 1);
+}
+
+/*
+ * Adds one USB MIDI packet to the output buffer.
+ */
+static void snd_usbmidi_output_standard_packet(struct urb *urb, uint8_t p0,
+					       uint8_t p1, uint8_t p2,
+					       uint8_t p3)
+{
+
+	uint8_t *buf =
+		(uint8_t *)urb->transfer_buffer + urb->transfer_buffer_length;
+	buf[0] = p0;
+	buf[1] = p1;
+	buf[2] = p2;
+	buf[3] = p3;
+	urb->transfer_buffer_length += 4;
+}
+
+/*
+ * Adds one Midiman packet to the output buffer.
+ */
+static void snd_usbmidi_output_midiman_packet(struct urb *urb, uint8_t p0,
+					      uint8_t p1, uint8_t p2,
+					      uint8_t p3)
+{
+
+	uint8_t *buf =
+		(uint8_t *)urb->transfer_buffer + urb->transfer_buffer_length;
+	buf[0] = p1;
+	buf[1] = p2;
+	buf[2] = p3;
+	buf[3] = (p0 & 0xf0) | snd_usbmidi_cin_length[p0 & 0x0f];
+	urb->transfer_buffer_length += 4;
+}
+
+/*
+ * Converts MIDI commands to USB MIDI packets.
+ */
+static void snd_usbmidi_transmit_byte(struct usbmidi_out_port *port,
+				      uint8_t b, struct urb *urb)
+{
+	uint8_t p0 = port->cable;
+	void (*output_packet)(struct urb*, uint8_t, uint8_t, uint8_t, uint8_t) =
+		port->ep->umidi->usb_protocol_ops->output_packet;
+
+	if (b >= 0xf8) {
+		output_packet(urb, p0 | 0x0f, b, 0, 0);
+	} else if (b >= 0xf0) {
+		switch (b) {
+		case 0xf0:
+			port->data[0] = b;
+			port->state = STATE_SYSEX_1;
+			break;
+		case 0xf1:
+		case 0xf3:
+			port->data[0] = b;
+			port->state = STATE_1PARAM;
+			break;
+		case 0xf2:
+			port->data[0] = b;
+			port->state = STATE_2PARAM_1;
+			break;
+		case 0xf4:
+		case 0xf5:
+			port->state = STATE_UNKNOWN;
+			break;
+		case 0xf6:
+			output_packet(urb, p0 | 0x05, 0xf6, 0, 0);
+			port->state = STATE_UNKNOWN;
+			break;
+		case 0xf7:
+			switch (port->state) {
+			case STATE_SYSEX_0:
+				output_packet(urb, p0 | 0x05, 0xf7, 0, 0);
+				break;
+			case STATE_SYSEX_1:
+				output_packet(urb, p0 | 0x06, port->data[0],
+					      0xf7, 0);
+				break;
+			case STATE_SYSEX_2:
+				output_packet(urb, p0 | 0x07, port->data[0],
+					      port->data[1], 0xf7);
+				break;
+			}
+			port->state = STATE_UNKNOWN;
+			break;
+		}
+	} else if (b >= 0x80) {
+		port->data[0] = b;
+		if (b >= 0xc0 && b <= 0xdf)
+			port->state = STATE_1PARAM;
+		else
+			port->state = STATE_2PARAM_1;
+	} else { /* b < 0x80 */
+		switch (port->state) {
+		case STATE_1PARAM:
+			if (port->data[0] < 0xf0) {
+				p0 |= port->data[0] >> 4;
+			} else {
+				p0 |= 0x02;
+				port->state = STATE_UNKNOWN;
+			}
+			output_packet(urb, p0, port->data[0], b, 0);
+			break;
+		case STATE_2PARAM_1:
+			port->data[1] = b;
+			port->state = STATE_2PARAM_2;
+			break;
+		case STATE_2PARAM_2:
+			if (port->data[0] < 0xf0) {
+				p0 |= port->data[0] >> 4;
+				port->state = STATE_2PARAM_1;
+			} else {
+				p0 |= 0x03;
+				port->state = STATE_UNKNOWN;
+			}
+			output_packet(urb, p0, port->data[0], port->data[1], b);
+			break;
+		case STATE_SYSEX_0:
+			port->data[0] = b;
+			port->state = STATE_SYSEX_1;
+			break;
+		case STATE_SYSEX_1:
+			port->data[1] = b;
+			port->state = STATE_SYSEX_2;
+			break;
+		case STATE_SYSEX_2:
+			output_packet(urb, p0 | 0x04, port->data[0],
+				      port->data[1], b);
+			port->state = STATE_SYSEX_0;
+			break;
+		}
+	}
+}
+
+static void snd_usbmidi_standard_output(struct snd_usb_midi_out_endpoint *ep,
+					struct urb *urb)
+{
+	int p;
+
+	/* FIXME: lower-numbered ports can starve higher-numbered ports */
+	for (p = 0; p < 0x10; ++p) {
+		struct usbmidi_out_port *port = &ep->ports[p];
+		if (!port->active)
+			continue;
+		while (urb->transfer_buffer_length + 3 < ep->max_transfer) {
+			uint8_t b;
+			if (snd_rawmidi_transmit(port->substream, &b, 1) != 1) {
+				port->active = 0;
+				break;
+			}
+			snd_usbmidi_transmit_byte(port, b, urb);
+		}
+	}
+}
+
+static const struct usb_protocol_ops snd_usbmidi_standard_ops = {
+	.input = snd_usbmidi_standard_input,
+	.output = snd_usbmidi_standard_output,
+	.output_packet = snd_usbmidi_output_standard_packet,
+};
+
+static const struct usb_protocol_ops snd_usbmidi_midiman_ops = {
+	.input = snd_usbmidi_midiman_input,
+	.output = snd_usbmidi_standard_output,
+	.output_packet = snd_usbmidi_output_midiman_packet,
+};
+
+static const
+struct usb_protocol_ops snd_usbmidi_maudio_broken_running_status_ops = {
+	.input = snd_usbmidi_maudio_broken_running_status_input,
+	.output = snd_usbmidi_standard_output,
+	.output_packet = snd_usbmidi_output_standard_packet,
+};
+
+static const struct usb_protocol_ops snd_usbmidi_cme_ops = {
+	.input = snd_usbmidi_cme_input,
+	.output = snd_usbmidi_standard_output,
+	.output_packet = snd_usbmidi_output_standard_packet,
+};
+
+static const struct usb_protocol_ops snd_usbmidi_ch345_broken_sysex_ops = {
+	.input = ch345_broken_sysex_input,
+	.output = snd_usbmidi_standard_output,
+	.output_packet = snd_usbmidi_output_standard_packet,
+};
+
+/*
+ * AKAI MPD16 protocol:
+ *
+ * For control port (endpoint 1):
+ * ==============================
+ * One or more chunks consisting of first byte of (0x10 | msg_len) and then a
+ * SysEx message (msg_len=9 bytes long).
+ *
+ * For data port (endpoint 2):
+ * ===========================
+ * One or more chunks consisting of first byte of (0x20 | msg_len) and then a
+ * MIDI message (msg_len bytes long)
+ *
+ * Messages sent: Active Sense, Note On, Poly Pressure, Control Change.
+ */
+static void snd_usbmidi_akai_input(struct snd_usb_midi_in_endpoint *ep,
+				   uint8_t *buffer, int buffer_length)
+{
+	unsigned int pos = 0;
+	unsigned int len = (unsigned int)buffer_length;
+	while (pos < len) {
+		unsigned int port = (buffer[pos] >> 4) - 1;
+		unsigned int msg_len = buffer[pos] & 0x0f;
+		pos++;
+		if (pos + msg_len <= len && port < 2)
+			snd_usbmidi_input_data(ep, 0, &buffer[pos], msg_len);
+		pos += msg_len;
+	}
+}
+
+#define MAX_AKAI_SYSEX_LEN 9
+
+static void snd_usbmidi_akai_output(struct snd_usb_midi_out_endpoint *ep,
+				    struct urb *urb)
+{
+	uint8_t *msg;
+	int pos, end, count, buf_end;
+	uint8_t tmp[MAX_AKAI_SYSEX_LEN];
+	struct snd_rawmidi_substream *substream = ep->ports[0].substream;
+
+	if (!ep->ports[0].active)
+		return;
+
+	msg = urb->transfer_buffer + urb->transfer_buffer_length;
+	buf_end = ep->max_transfer - MAX_AKAI_SYSEX_LEN - 1;
+
+	/* only try adding more data when there's space for at least 1 SysEx */
+	while (urb->transfer_buffer_length < buf_end) {
+		count = snd_rawmidi_transmit_peek(substream,
+						  tmp, MAX_AKAI_SYSEX_LEN);
+		if (!count) {
+			ep->ports[0].active = 0;
+			return;
+		}
+		/* try to skip non-SysEx data */
+		for (pos = 0; pos < count && tmp[pos] != 0xF0; pos++)
+			;
+
+		if (pos > 0) {
+			snd_rawmidi_transmit_ack(substream, pos);
+			continue;
+		}
+
+		/* look for the start or end marker */
+		for (end = 1; end < count && tmp[end] < 0xF0; end++)
+			;
+
+		/* next SysEx started before the end of current one */
+		if (end < count && tmp[end] == 0xF0) {
+			/* it's incomplete - drop it */
+			snd_rawmidi_transmit_ack(substream, end);
+			continue;
+		}
+		/* SysEx complete */
+		if (end < count && tmp[end] == 0xF7) {
+			/* queue it, ack it, and get the next one */
+			count = end + 1;
+			msg[0] = 0x10 | count;
+			memcpy(&msg[1], tmp, count);
+			snd_rawmidi_transmit_ack(substream, count);
+			urb->transfer_buffer_length += count + 1;
+			msg += count + 1;
+			continue;
+		}
+		/* less than 9 bytes and no end byte - wait for more */
+		if (count < MAX_AKAI_SYSEX_LEN) {
+			ep->ports[0].active = 0;
+			return;
+		}
+		/* 9 bytes and no end marker in sight - malformed, skip it */
+		snd_rawmidi_transmit_ack(substream, count);
+	}
+}
+
+static const struct usb_protocol_ops snd_usbmidi_akai_ops = {
+	.input = snd_usbmidi_akai_input,
+	.output = snd_usbmidi_akai_output,
+};
+
+/*
+ * Novation USB MIDI protocol: number of data bytes is in the first byte
+ * (when receiving) (+1!) or in the second byte (when sending); data begins
+ * at the third byte.
+ */
+
+static void snd_usbmidi_novation_input(struct snd_usb_midi_in_endpoint *ep,
+				       uint8_t *buffer, int buffer_length)
+{
+	if (buffer_length < 2 || !buffer[0] || buffer_length < buffer[0] + 1)
+		return;
+	snd_usbmidi_input_data(ep, 0, &buffer[2], buffer[0] - 1);
+}
+
+static void snd_usbmidi_novation_output(struct snd_usb_midi_out_endpoint *ep,
+					struct urb *urb)
+{
+	uint8_t *transfer_buffer;
+	int count;
+
+	if (!ep->ports[0].active)
+		return;
+	transfer_buffer = urb->transfer_buffer;
+	count = snd_rawmidi_transmit(ep->ports[0].substream,
+				     &transfer_buffer[2],
+				     ep->max_transfer - 2);
+	if (count < 1) {
+		ep->ports[0].active = 0;
+		return;
+	}
+	transfer_buffer[0] = 0;
+	transfer_buffer[1] = count;
+	urb->transfer_buffer_length = 2 + count;
+}
+
+static const struct usb_protocol_ops snd_usbmidi_novation_ops = {
+	.input = snd_usbmidi_novation_input,
+	.output = snd_usbmidi_novation_output,
+};
+
+/*
+ * "raw" protocol: just move raw MIDI bytes from/to the endpoint
+ */
+
+static void snd_usbmidi_raw_input(struct snd_usb_midi_in_endpoint *ep,
+				  uint8_t *buffer, int buffer_length)
+{
+	snd_usbmidi_input_data(ep, 0, buffer, buffer_length);
+}
+
+static void snd_usbmidi_raw_output(struct snd_usb_midi_out_endpoint *ep,
+				   struct urb *urb)
+{
+	int count;
+
+	if (!ep->ports[0].active)
+		return;
+	count = snd_rawmidi_transmit(ep->ports[0].substream,
+				     urb->transfer_buffer,
+				     ep->max_transfer);
+	if (count < 1) {
+		ep->ports[0].active = 0;
+		return;
+	}
+	urb->transfer_buffer_length = count;
+}
+
+static const struct usb_protocol_ops snd_usbmidi_raw_ops = {
+	.input = snd_usbmidi_raw_input,
+	.output = snd_usbmidi_raw_output,
+};
+
+/*
+ * FTDI protocol: raw MIDI bytes, but input packets have two modem status bytes.
+ */
+
+static void snd_usbmidi_ftdi_input(struct snd_usb_midi_in_endpoint *ep,
+				   uint8_t *buffer, int buffer_length)
+{
+	if (buffer_length > 2)
+		snd_usbmidi_input_data(ep, 0, buffer + 2, buffer_length - 2);
+}
+
+static const struct usb_protocol_ops snd_usbmidi_ftdi_ops = {
+	.input = snd_usbmidi_ftdi_input,
+	.output = snd_usbmidi_raw_output,
+};
+
+static void snd_usbmidi_us122l_input(struct snd_usb_midi_in_endpoint *ep,
+				     uint8_t *buffer, int buffer_length)
+{
+	if (buffer_length != 9)
+		return;
+	buffer_length = 8;
+	while (buffer_length && buffer[buffer_length - 1] == 0xFD)
+		buffer_length--;
+	if (buffer_length)
+		snd_usbmidi_input_data(ep, 0, buffer, buffer_length);
+}
+
+static void snd_usbmidi_us122l_output(struct snd_usb_midi_out_endpoint *ep,
+				      struct urb *urb)
+{
+	int count;
+
+	if (!ep->ports[0].active)
+		return;
+	switch (snd_usb_get_speed(ep->umidi->dev)) {
+	case USB_SPEED_HIGH:
+	case USB_SPEED_SUPER:
+	case USB_SPEED_SUPER_PLUS:
+		count = 1;
+		break;
+	default:
+		count = 2;
+	}
+	count = snd_rawmidi_transmit(ep->ports[0].substream,
+				     urb->transfer_buffer,
+				     count);
+	if (count < 1) {
+		ep->ports[0].active = 0;
+		return;
+	}
+
+	memset(urb->transfer_buffer + count, 0xFD, ep->max_transfer - count);
+	urb->transfer_buffer_length = ep->max_transfer;
+}
+
+static const struct usb_protocol_ops snd_usbmidi_122l_ops = {
+	.input = snd_usbmidi_us122l_input,
+	.output = snd_usbmidi_us122l_output,
+};
+
+/*
+ * Emagic USB MIDI protocol: raw MIDI with "F5 xx" port switching.
+ */
+
+static void snd_usbmidi_emagic_init_out(struct snd_usb_midi_out_endpoint *ep)
+{
+	static const u8 init_data[] = {
+		/* initialization magic: "get version" */
+		0xf0,
+		0x00, 0x20, 0x31,	/* Emagic */
+		0x64,			/* Unitor8 */
+		0x0b,			/* version number request */
+		0x00,			/* command version */
+		0x00,			/* EEPROM, box 0 */
+		0xf7
+	};
+	send_bulk_static_data(ep, init_data, sizeof(init_data));
+	/* while we're at it, pour on more magic */
+	send_bulk_static_data(ep, init_data, sizeof(init_data));
+}
+
+static void snd_usbmidi_emagic_finish_out(struct snd_usb_midi_out_endpoint *ep)
+{
+	static const u8 finish_data[] = {
+		/* switch to patch mode with last preset */
+		0xf0,
+		0x00, 0x20, 0x31,	/* Emagic */
+		0x64,			/* Unitor8 */
+		0x10,			/* patch switch command */
+		0x00,			/* command version */
+		0x7f,			/* to all boxes */
+		0x40,			/* last preset in EEPROM */
+		0xf7
+	};
+	send_bulk_static_data(ep, finish_data, sizeof(finish_data));
+}
+
+static void snd_usbmidi_emagic_input(struct snd_usb_midi_in_endpoint *ep,
+				     uint8_t *buffer, int buffer_length)
+{
+	int i;
+
+	/* FF indicates end of valid data */
+	for (i = 0; i < buffer_length; ++i)
+		if (buffer[i] == 0xff) {
+			buffer_length = i;
+			break;
+		}
+
+	/* handle F5 at end of last buffer */
+	if (ep->seen_f5)
+		goto switch_port;
+
+	while (buffer_length > 0) {
+		/* determine size of data until next F5 */
+		for (i = 0; i < buffer_length; ++i)
+			if (buffer[i] == 0xf5)
+				break;
+		snd_usbmidi_input_data(ep, ep->current_port, buffer, i);
+		buffer += i;
+		buffer_length -= i;
+
+		if (buffer_length <= 0)
+			break;
+		/* assert(buffer[0] == 0xf5); */
+		ep->seen_f5 = 1;
+		++buffer;
+		--buffer_length;
+
+	switch_port:
+		if (buffer_length <= 0)
+			break;
+		if (buffer[0] < 0x80) {
+			ep->current_port = (buffer[0] - 1) & 15;
+			++buffer;
+			--buffer_length;
+		}
+		ep->seen_f5 = 0;
+	}
+}
+
+static void snd_usbmidi_emagic_output(struct snd_usb_midi_out_endpoint *ep,
+				      struct urb *urb)
+{
+	int port0 = ep->current_port;
+	uint8_t *buf = urb->transfer_buffer;
+	int buf_free = ep->max_transfer;
+	int length, i;
+
+	for (i = 0; i < 0x10; ++i) {
+		/* round-robin, starting at the last current port */
+		int portnum = (port0 + i) & 15;
+		struct usbmidi_out_port *port = &ep->ports[portnum];
+
+		if (!port->active)
+			continue;
+		if (snd_rawmidi_transmit_peek(port->substream, buf, 1) != 1) {
+			port->active = 0;
+			continue;
+		}
+
+		if (portnum != ep->current_port) {
+			if (buf_free < 2)
+				break;
+			ep->current_port = portnum;
+			buf[0] = 0xf5;
+			buf[1] = (portnum + 1) & 15;
+			buf += 2;
+			buf_free -= 2;
+		}
+
+		if (buf_free < 1)
+			break;
+		length = snd_rawmidi_transmit(port->substream, buf, buf_free);
+		if (length > 0) {
+			buf += length;
+			buf_free -= length;
+			if (buf_free < 1)
+				break;
+		}
+	}
+	if (buf_free < ep->max_transfer && buf_free > 0) {
+		*buf = 0xff;
+		--buf_free;
+	}
+	urb->transfer_buffer_length = ep->max_transfer - buf_free;
+}
+
+static const struct usb_protocol_ops snd_usbmidi_emagic_ops = {
+	.input = snd_usbmidi_emagic_input,
+	.output = snd_usbmidi_emagic_output,
+	.init_out_endpoint = snd_usbmidi_emagic_init_out,
+	.finish_out_endpoint = snd_usbmidi_emagic_finish_out,
+};
+
+
+static void update_roland_altsetting(struct snd_usb_midi *umidi)
+{
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	struct usb_interface_descriptor *intfd;
+	int is_light_load;
+
+	intf = umidi->iface;
+	is_light_load = intf->cur_altsetting != intf->altsetting;
+	if (umidi->roland_load_ctl->private_value == is_light_load)
+		return;
+	hostif = &intf->altsetting[umidi->roland_load_ctl->private_value];
+	intfd = get_iface_desc(hostif);
+	snd_usbmidi_input_stop(&umidi->list);
+	usb_set_interface(umidi->dev, intfd->bInterfaceNumber,
+			  intfd->bAlternateSetting);
+	snd_usbmidi_input_start(&umidi->list);
+}
+
+static int substream_open(struct snd_rawmidi_substream *substream, int dir,
+			  int open)
+{
+	struct snd_usb_midi *umidi = substream->rmidi->private_data;
+	struct snd_kcontrol *ctl;
+
+	down_read(&umidi->disc_rwsem);
+	if (umidi->disconnected) {
+		up_read(&umidi->disc_rwsem);
+		return open ? -ENODEV : 0;
+	}
+
+	mutex_lock(&umidi->mutex);
+	if (open) {
+		if (!umidi->opened[0] && !umidi->opened[1]) {
+			if (umidi->roland_load_ctl) {
+				ctl = umidi->roland_load_ctl;
+				ctl->vd[0].access |=
+					SNDRV_CTL_ELEM_ACCESS_INACTIVE;
+				snd_ctl_notify(umidi->card,
+				       SNDRV_CTL_EVENT_MASK_INFO, &ctl->id);
+				update_roland_altsetting(umidi);
+			}
+		}
+		umidi->opened[dir]++;
+		if (umidi->opened[1])
+			snd_usbmidi_input_start(&umidi->list);
+	} else {
+		umidi->opened[dir]--;
+		if (!umidi->opened[1])
+			snd_usbmidi_input_stop(&umidi->list);
+		if (!umidi->opened[0] && !umidi->opened[1]) {
+			if (umidi->roland_load_ctl) {
+				ctl = umidi->roland_load_ctl;
+				ctl->vd[0].access &=
+					~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
+				snd_ctl_notify(umidi->card,
+				       SNDRV_CTL_EVENT_MASK_INFO, &ctl->id);
+			}
+		}
+	}
+	mutex_unlock(&umidi->mutex);
+	up_read(&umidi->disc_rwsem);
+	return 0;
+}
+
+static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_usb_midi *umidi = substream->rmidi->private_data;
+	struct usbmidi_out_port *port = NULL;
+	int i, j;
+
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i)
+		if (umidi->endpoints[i].out)
+			for (j = 0; j < 0x10; ++j)
+				if (umidi->endpoints[i].out->ports[j].substream == substream) {
+					port = &umidi->endpoints[i].out->ports[j];
+					break;
+				}
+	if (!port)
+		return -ENXIO;
+
+	substream->runtime->private_data = port;
+	port->state = STATE_UNKNOWN;
+	return substream_open(substream, 0, 1);
+}
+
+static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
+{
+	struct usbmidi_out_port *port = substream->runtime->private_data;
+
+	cancel_work_sync(&port->ep->work);
+	return substream_open(substream, 0, 0);
+}
+
+static void snd_usbmidi_output_trigger(struct snd_rawmidi_substream *substream,
+				       int up)
+{
+	struct usbmidi_out_port *port =
+		(struct usbmidi_out_port *)substream->runtime->private_data;
+
+	port->active = up;
+	if (up) {
+		if (port->ep->umidi->disconnected) {
+			/* gobble up remaining bytes to prevent wait in
+			 * snd_rawmidi_drain_output */
+			snd_rawmidi_proceed(substream);
+			return;
+		}
+		queue_work(system_highpri_wq, &port->ep->work);
+	}
+}
+
+static void snd_usbmidi_output_drain(struct snd_rawmidi_substream *substream)
+{
+	struct usbmidi_out_port *port = substream->runtime->private_data;
+	struct snd_usb_midi_out_endpoint *ep = port->ep;
+	unsigned int drain_urbs;
+	DEFINE_WAIT(wait);
+	long timeout = msecs_to_jiffies(50);
+
+	if (ep->umidi->disconnected)
+		return;
+	/*
+	 * The substream buffer is empty, but some data might still be in the
+	 * currently active URBs, so we have to wait for those to complete.
+	 */
+	spin_lock_irq(&ep->buffer_lock);
+	drain_urbs = ep->active_urbs;
+	if (drain_urbs) {
+		ep->drain_urbs |= drain_urbs;
+		do {
+			prepare_to_wait(&ep->drain_wait, &wait,
+					TASK_UNINTERRUPTIBLE);
+			spin_unlock_irq(&ep->buffer_lock);
+			timeout = schedule_timeout(timeout);
+			spin_lock_irq(&ep->buffer_lock);
+			drain_urbs &= ep->drain_urbs;
+		} while (drain_urbs && timeout);
+		finish_wait(&ep->drain_wait, &wait);
+	}
+	port->active = 0;
+	spin_unlock_irq(&ep->buffer_lock);
+}
+
+static int snd_usbmidi_input_open(struct snd_rawmidi_substream *substream)
+{
+	return substream_open(substream, 1, 1);
+}
+
+static int snd_usbmidi_input_close(struct snd_rawmidi_substream *substream)
+{
+	return substream_open(substream, 1, 0);
+}
+
+static void snd_usbmidi_input_trigger(struct snd_rawmidi_substream *substream,
+				      int up)
+{
+	struct snd_usb_midi *umidi = substream->rmidi->private_data;
+
+	if (up)
+		set_bit(substream->number, &umidi->input_triggered);
+	else
+		clear_bit(substream->number, &umidi->input_triggered);
+}
+
+static const struct snd_rawmidi_ops snd_usbmidi_output_ops = {
+	.open = snd_usbmidi_output_open,
+	.close = snd_usbmidi_output_close,
+	.trigger = snd_usbmidi_output_trigger,
+	.drain = snd_usbmidi_output_drain,
+};
+
+static const struct snd_rawmidi_ops snd_usbmidi_input_ops = {
+	.open = snd_usbmidi_input_open,
+	.close = snd_usbmidi_input_close,
+	.trigger = snd_usbmidi_input_trigger
+};
+
+static void free_urb_and_buffer(struct snd_usb_midi *umidi, struct urb *urb,
+				unsigned int buffer_length)
+{
+	usb_free_coherent(umidi->dev, buffer_length,
+			  urb->transfer_buffer, urb->transfer_dma);
+	usb_free_urb(urb);
+}
+
+/*
+ * Frees an input endpoint.
+ * May be called when ep hasn't been initialized completely.
+ */
+static void snd_usbmidi_in_endpoint_delete(struct snd_usb_midi_in_endpoint *ep)
+{
+	unsigned int i;
+
+	for (i = 0; i < INPUT_URBS; ++i)
+		if (ep->urbs[i])
+			free_urb_and_buffer(ep->umidi, ep->urbs[i],
+					    ep->urbs[i]->transfer_buffer_length);
+	kfree(ep);
+}
+
+/*
+ * Creates an input endpoint.
+ */
+static int snd_usbmidi_in_endpoint_create(struct snd_usb_midi *umidi,
+					  struct snd_usb_midi_endpoint_info *ep_info,
+					  struct snd_usb_midi_endpoint *rep)
+{
+	struct snd_usb_midi_in_endpoint *ep;
+	void *buffer;
+	unsigned int pipe;
+	int length;
+	unsigned int i;
+	int err;
+
+	rep->in = NULL;
+	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+	ep->umidi = umidi;
+
+	for (i = 0; i < INPUT_URBS; ++i) {
+		ep->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
+		if (!ep->urbs[i]) {
+			err = -ENOMEM;
+			goto error;
+		}
+	}
+	if (ep_info->in_interval)
+		pipe = usb_rcvintpipe(umidi->dev, ep_info->in_ep);
+	else
+		pipe = usb_rcvbulkpipe(umidi->dev, ep_info->in_ep);
+	length = usb_maxpacket(umidi->dev, pipe, 0);
+	for (i = 0; i < INPUT_URBS; ++i) {
+		buffer = usb_alloc_coherent(umidi->dev, length, GFP_KERNEL,
+					    &ep->urbs[i]->transfer_dma);
+		if (!buffer) {
+			err = -ENOMEM;
+			goto error;
+		}
+		if (ep_info->in_interval)
+			usb_fill_int_urb(ep->urbs[i], umidi->dev,
+					 pipe, buffer, length,
+					 snd_usbmidi_in_urb_complete,
+					 ep, ep_info->in_interval);
+		else
+			usb_fill_bulk_urb(ep->urbs[i], umidi->dev,
+					  pipe, buffer, length,
+					  snd_usbmidi_in_urb_complete, ep);
+		ep->urbs[i]->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		err = usb_urb_ep_type_check(ep->urbs[i]);
+		if (err < 0) {
+			dev_err(&umidi->dev->dev, "invalid MIDI in EP %x\n",
+				ep_info->in_ep);
+			goto error;
+		}
+	}
+
+	rep->in = ep;
+	return 0;
+
+ error:
+	snd_usbmidi_in_endpoint_delete(ep);
+	return err;
+}
+
+/*
+ * Frees an output endpoint.
+ * May be called when ep hasn't been initialized completely.
+ */
+static void snd_usbmidi_out_endpoint_clear(struct snd_usb_midi_out_endpoint *ep)
+{
+	unsigned int i;
+
+	for (i = 0; i < OUTPUT_URBS; ++i)
+		if (ep->urbs[i].urb) {
+			free_urb_and_buffer(ep->umidi, ep->urbs[i].urb,
+					    ep->max_transfer);
+			ep->urbs[i].urb = NULL;
+		}
+}
+
+static void snd_usbmidi_out_endpoint_delete(struct snd_usb_midi_out_endpoint *ep)
+{
+	snd_usbmidi_out_endpoint_clear(ep);
+	kfree(ep);
+}
+
+/*
+ * Creates an output endpoint, and initializes output ports.
+ */
+static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi *umidi,
+					   struct snd_usb_midi_endpoint_info *ep_info,
+					   struct snd_usb_midi_endpoint *rep)
+{
+	struct snd_usb_midi_out_endpoint *ep;
+	unsigned int i;
+	unsigned int pipe;
+	void *buffer;
+	int err;
+
+	rep->out = NULL;
+	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+	ep->umidi = umidi;
+
+	for (i = 0; i < OUTPUT_URBS; ++i) {
+		ep->urbs[i].urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!ep->urbs[i].urb) {
+			err = -ENOMEM;
+			goto error;
+		}
+		ep->urbs[i].ep = ep;
+	}
+	if (ep_info->out_interval)
+		pipe = usb_sndintpipe(umidi->dev, ep_info->out_ep);
+	else
+		pipe = usb_sndbulkpipe(umidi->dev, ep_info->out_ep);
+	switch (umidi->usb_id) {
+	default:
+		ep->max_transfer = usb_maxpacket(umidi->dev, pipe, 1);
+		break;
+		/*
+		 * Various chips declare a packet size larger than 4 bytes, but
+		 * do not actually work with larger packets:
+		 */
+	case USB_ID(0x0a67, 0x5011): /* Medeli DD305 */
+	case USB_ID(0x0a92, 0x1020): /* ESI M4U */
+	case USB_ID(0x1430, 0x474b): /* RedOctane GH MIDI INTERFACE */
+	case USB_ID(0x15ca, 0x0101): /* Textech USB Midi Cable */
+	case USB_ID(0x15ca, 0x1806): /* Textech USB Midi Cable */
+	case USB_ID(0x1a86, 0x752d): /* QinHeng CH345 "USB2.0-MIDI" */
+	case USB_ID(0xfc08, 0x0101): /* Unknown vendor Cable */
+		ep->max_transfer = 4;
+		break;
+		/*
+		 * Some devices only work with 9 bytes packet size:
+		 */
+	case USB_ID(0x0644, 0x800e): /* Tascam US-122L */
+	case USB_ID(0x0644, 0x800f): /* Tascam US-144 */
+		ep->max_transfer = 9;
+		break;
+	}
+	for (i = 0; i < OUTPUT_URBS; ++i) {
+		buffer = usb_alloc_coherent(umidi->dev,
+					    ep->max_transfer, GFP_KERNEL,
+					    &ep->urbs[i].urb->transfer_dma);
+		if (!buffer) {
+			err = -ENOMEM;
+			goto error;
+		}
+		if (ep_info->out_interval)
+			usb_fill_int_urb(ep->urbs[i].urb, umidi->dev,
+					 pipe, buffer, ep->max_transfer,
+					 snd_usbmidi_out_urb_complete,
+					 &ep->urbs[i], ep_info->out_interval);
+		else
+			usb_fill_bulk_urb(ep->urbs[i].urb, umidi->dev,
+					  pipe, buffer, ep->max_transfer,
+					  snd_usbmidi_out_urb_complete,
+					  &ep->urbs[i]);
+		err = usb_urb_ep_type_check(ep->urbs[i].urb);
+		if (err < 0) {
+			dev_err(&umidi->dev->dev, "invalid MIDI out EP %x\n",
+				ep_info->out_ep);
+			goto error;
+		}
+		ep->urbs[i].urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+	}
+
+	spin_lock_init(&ep->buffer_lock);
+	INIT_WORK(&ep->work, snd_usbmidi_out_work);
+	init_waitqueue_head(&ep->drain_wait);
+
+	for (i = 0; i < 0x10; ++i)
+		if (ep_info->out_cables & (1 << i)) {
+			ep->ports[i].ep = ep;
+			ep->ports[i].cable = i << 4;
+		}
+
+	if (umidi->usb_protocol_ops->init_out_endpoint)
+		umidi->usb_protocol_ops->init_out_endpoint(ep);
+
+	rep->out = ep;
+	return 0;
+
+ error:
+	snd_usbmidi_out_endpoint_delete(ep);
+	return err;
+}
+
+/*
+ * Frees everything.
+ */
+static void snd_usbmidi_free(struct snd_usb_midi *umidi)
+{
+	int i;
+
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
+		if (ep->out)
+			snd_usbmidi_out_endpoint_delete(ep->out);
+		if (ep->in)
+			snd_usbmidi_in_endpoint_delete(ep->in);
+	}
+	mutex_destroy(&umidi->mutex);
+	kfree(umidi);
+}
+
+/*
+ * Unlinks all URBs (must be done before the usb_device is deleted).
+ */
+void snd_usbmidi_disconnect(struct list_head *p)
+{
+	struct snd_usb_midi *umidi;
+	unsigned int i, j;
+
+	umidi = list_entry(p, struct snd_usb_midi, list);
+	/*
+	 * an URB's completion handler may start the timer and
+	 * a timer may submit an URB. To reliably break the cycle
+	 * a flag under lock must be used
+	 */
+	down_write(&umidi->disc_rwsem);
+	spin_lock_irq(&umidi->disc_lock);
+	umidi->disconnected = 1;
+	spin_unlock_irq(&umidi->disc_lock);
+	up_write(&umidi->disc_rwsem);
+
+	del_timer_sync(&umidi->error_timer);
+
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
+		if (ep->out)
+			cancel_work_sync(&ep->out->work);
+		if (ep->out) {
+			for (j = 0; j < OUTPUT_URBS; ++j)
+				usb_kill_urb(ep->out->urbs[j].urb);
+			if (umidi->usb_protocol_ops->finish_out_endpoint)
+				umidi->usb_protocol_ops->finish_out_endpoint(ep->out);
+			ep->out->active_urbs = 0;
+			if (ep->out->drain_urbs) {
+				ep->out->drain_urbs = 0;
+				wake_up(&ep->out->drain_wait);
+			}
+		}
+		if (ep->in)
+			for (j = 0; j < INPUT_URBS; ++j)
+				usb_kill_urb(ep->in->urbs[j]);
+		/* free endpoints here; later call can result in Oops */
+		if (ep->out)
+			snd_usbmidi_out_endpoint_clear(ep->out);
+		if (ep->in) {
+			snd_usbmidi_in_endpoint_delete(ep->in);
+			ep->in = NULL;
+		}
+	}
+}
+EXPORT_SYMBOL(snd_usbmidi_disconnect);
+
+static void snd_usbmidi_rawmidi_free(struct snd_rawmidi *rmidi)
+{
+	struct snd_usb_midi *umidi = rmidi->private_data;
+	snd_usbmidi_free(umidi);
+}
+
+static struct snd_rawmidi_substream *snd_usbmidi_find_substream(struct snd_usb_midi *umidi,
+								int stream,
+								int number)
+{
+	struct snd_rawmidi_substream *substream;
+
+	list_for_each_entry(substream, &umidi->rmidi->streams[stream].substreams,
+			    list) {
+		if (substream->number == number)
+			return substream;
+	}
+	return NULL;
+}
+
+/*
+ * This list specifies names for ports that do not fit into the standard
+ * "(product) MIDI (n)" schema because they aren't external MIDI ports,
+ * such as internal control or synthesizer ports.
+ */
+static struct port_info {
+	u32 id;
+	short int port;
+	short int voices;
+	const char *name;
+	unsigned int seq_flags;
+} snd_usbmidi_port_info[] = {
+#define PORT_INFO(vendor, product, num, name_, voices_, flags) \
+	{ .id = USB_ID(vendor, product), \
+	  .port = num, .voices = voices_, \
+	  .name = name_, .seq_flags = flags }
+#define EXTERNAL_PORT(vendor, product, num, name) \
+	PORT_INFO(vendor, product, num, name, 0, \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
+		  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
+		  SNDRV_SEQ_PORT_TYPE_PORT)
+#define CONTROL_PORT(vendor, product, num, name) \
+	PORT_INFO(vendor, product, num, name, 0, \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
+		  SNDRV_SEQ_PORT_TYPE_HARDWARE)
+#define GM_SYNTH_PORT(vendor, product, num, name, voices) \
+	PORT_INFO(vendor, product, num, name, voices, \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GM | \
+		  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
+		  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)
+#define ROLAND_SYNTH_PORT(vendor, product, num, name, voices) \
+	PORT_INFO(vendor, product, num, name, voices, \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GM | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GM2 | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GS | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_XG | \
+		  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
+		  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)
+#define SOUNDCANVAS_PORT(vendor, product, num, name, voices) \
+	PORT_INFO(vendor, product, num, name, voices, \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GM | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GM2 | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_GS | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_XG | \
+		  SNDRV_SEQ_PORT_TYPE_MIDI_MT32 | \
+		  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
+		  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)
+	/* Yamaha MOTIF XF */
+	GM_SYNTH_PORT(0x0499, 0x105c, 0, "%s Tone Generator", 128),
+	CONTROL_PORT(0x0499, 0x105c, 1, "%s Remote Control"),
+	EXTERNAL_PORT(0x0499, 0x105c, 2, "%s Thru"),
+	CONTROL_PORT(0x0499, 0x105c, 3, "%s Editor"),
+	/* Roland UA-100 */
+	CONTROL_PORT(0x0582, 0x0000, 2, "%s Control"),
+	/* Roland SC-8850 */
+	SOUNDCANVAS_PORT(0x0582, 0x0003, 0, "%s Part A", 128),
+	SOUNDCANVAS_PORT(0x0582, 0x0003, 1, "%s Part B", 128),
+	SOUNDCANVAS_PORT(0x0582, 0x0003, 2, "%s Part C", 128),
+	SOUNDCANVAS_PORT(0x0582, 0x0003, 3, "%s Part D", 128),
+	EXTERNAL_PORT(0x0582, 0x0003, 4, "%s MIDI 1"),
+	EXTERNAL_PORT(0x0582, 0x0003, 5, "%s MIDI 2"),
+	/* Roland U-8 */
+	EXTERNAL_PORT(0x0582, 0x0004, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x0004, 1, "%s Control"),
+	/* Roland SC-8820 */
+	SOUNDCANVAS_PORT(0x0582, 0x0007, 0, "%s Part A", 64),
+	SOUNDCANVAS_PORT(0x0582, 0x0007, 1, "%s Part B", 64),
+	EXTERNAL_PORT(0x0582, 0x0007, 2, "%s MIDI"),
+	/* Roland SK-500 */
+	SOUNDCANVAS_PORT(0x0582, 0x000b, 0, "%s Part A", 64),
+	SOUNDCANVAS_PORT(0x0582, 0x000b, 1, "%s Part B", 64),
+	EXTERNAL_PORT(0x0582, 0x000b, 2, "%s MIDI"),
+	/* Roland SC-D70 */
+	SOUNDCANVAS_PORT(0x0582, 0x000c, 0, "%s Part A", 64),
+	SOUNDCANVAS_PORT(0x0582, 0x000c, 1, "%s Part B", 64),
+	EXTERNAL_PORT(0x0582, 0x000c, 2, "%s MIDI"),
+	/* Edirol UM-880 */
+	CONTROL_PORT(0x0582, 0x0014, 8, "%s Control"),
+	/* Edirol SD-90 */
+	ROLAND_SYNTH_PORT(0x0582, 0x0016, 0, "%s Part A", 128),
+	ROLAND_SYNTH_PORT(0x0582, 0x0016, 1, "%s Part B", 128),
+	EXTERNAL_PORT(0x0582, 0x0016, 2, "%s MIDI 1"),
+	EXTERNAL_PORT(0x0582, 0x0016, 3, "%s MIDI 2"),
+	/* Edirol UM-550 */
+	CONTROL_PORT(0x0582, 0x0023, 5, "%s Control"),
+	/* Edirol SD-20 */
+	ROLAND_SYNTH_PORT(0x0582, 0x0027, 0, "%s Part A", 64),
+	ROLAND_SYNTH_PORT(0x0582, 0x0027, 1, "%s Part B", 64),
+	EXTERNAL_PORT(0x0582, 0x0027, 2, "%s MIDI"),
+	/* Edirol SD-80 */
+	ROLAND_SYNTH_PORT(0x0582, 0x0029, 0, "%s Part A", 128),
+	ROLAND_SYNTH_PORT(0x0582, 0x0029, 1, "%s Part B", 128),
+	EXTERNAL_PORT(0x0582, 0x0029, 2, "%s MIDI 1"),
+	EXTERNAL_PORT(0x0582, 0x0029, 3, "%s MIDI 2"),
+	/* Edirol UA-700 */
+	EXTERNAL_PORT(0x0582, 0x002b, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x002b, 1, "%s Control"),
+	/* Roland VariOS */
+	EXTERNAL_PORT(0x0582, 0x002f, 0, "%s MIDI"),
+	EXTERNAL_PORT(0x0582, 0x002f, 1, "%s External MIDI"),
+	EXTERNAL_PORT(0x0582, 0x002f, 2, "%s Sync"),
+	/* Edirol PCR */
+	EXTERNAL_PORT(0x0582, 0x0033, 0, "%s MIDI"),
+	EXTERNAL_PORT(0x0582, 0x0033, 1, "%s 1"),
+	EXTERNAL_PORT(0x0582, 0x0033, 2, "%s 2"),
+	/* BOSS GS-10 */
+	EXTERNAL_PORT(0x0582, 0x003b, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x003b, 1, "%s Control"),
+	/* Edirol UA-1000 */
+	EXTERNAL_PORT(0x0582, 0x0044, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x0044, 1, "%s Control"),
+	/* Edirol UR-80 */
+	EXTERNAL_PORT(0x0582, 0x0048, 0, "%s MIDI"),
+	EXTERNAL_PORT(0x0582, 0x0048, 1, "%s 1"),
+	EXTERNAL_PORT(0x0582, 0x0048, 2, "%s 2"),
+	/* Edirol PCR-A */
+	EXTERNAL_PORT(0x0582, 0x004d, 0, "%s MIDI"),
+	EXTERNAL_PORT(0x0582, 0x004d, 1, "%s 1"),
+	EXTERNAL_PORT(0x0582, 0x004d, 2, "%s 2"),
+	/* BOSS GT-PRO */
+	CONTROL_PORT(0x0582, 0x0089, 0, "%s Control"),
+	/* Edirol UM-3EX */
+	CONTROL_PORT(0x0582, 0x009a, 3, "%s Control"),
+	/* Roland VG-99 */
+	CONTROL_PORT(0x0582, 0x00b2, 0, "%s Control"),
+	EXTERNAL_PORT(0x0582, 0x00b2, 1, "%s MIDI"),
+	/* Cakewalk Sonar V-Studio 100 */
+	EXTERNAL_PORT(0x0582, 0x00eb, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x00eb, 1, "%s Control"),
+	/* Roland VB-99 */
+	CONTROL_PORT(0x0582, 0x0102, 0, "%s Control"),
+	EXTERNAL_PORT(0x0582, 0x0102, 1, "%s MIDI"),
+	/* Roland A-PRO */
+	EXTERNAL_PORT(0x0582, 0x010f, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x010f, 1, "%s 1"),
+	CONTROL_PORT(0x0582, 0x010f, 2, "%s 2"),
+	/* Roland SD-50 */
+	ROLAND_SYNTH_PORT(0x0582, 0x0114, 0, "%s Synth", 128),
+	EXTERNAL_PORT(0x0582, 0x0114, 1, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x0114, 2, "%s Control"),
+	/* Roland OCTA-CAPTURE */
+	EXTERNAL_PORT(0x0582, 0x0120, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x0120, 1, "%s Control"),
+	EXTERNAL_PORT(0x0582, 0x0121, 0, "%s MIDI"),
+	CONTROL_PORT(0x0582, 0x0121, 1, "%s Control"),
+	/* Roland SPD-SX */
+	CONTROL_PORT(0x0582, 0x0145, 0, "%s Control"),
+	EXTERNAL_PORT(0x0582, 0x0145, 1, "%s MIDI"),
+	/* Roland A-Series */
+	CONTROL_PORT(0x0582, 0x0156, 0, "%s Keyboard"),
+	EXTERNAL_PORT(0x0582, 0x0156, 1, "%s MIDI"),
+	/* Roland INTEGRA-7 */
+	ROLAND_SYNTH_PORT(0x0582, 0x015b, 0, "%s Synth", 128),
+	CONTROL_PORT(0x0582, 0x015b, 1, "%s Control"),
+	/* M-Audio MidiSport 8x8 */
+	CONTROL_PORT(0x0763, 0x1031, 8, "%s Control"),
+	CONTROL_PORT(0x0763, 0x1033, 8, "%s Control"),
+	/* MOTU Fastlane */
+	EXTERNAL_PORT(0x07fd, 0x0001, 0, "%s MIDI A"),
+	EXTERNAL_PORT(0x07fd, 0x0001, 1, "%s MIDI B"),
+	/* Emagic Unitor8/AMT8/MT4 */
+	EXTERNAL_PORT(0x086a, 0x0001, 8, "%s Broadcast"),
+	EXTERNAL_PORT(0x086a, 0x0002, 8, "%s Broadcast"),
+	EXTERNAL_PORT(0x086a, 0x0003, 4, "%s Broadcast"),
+	/* Akai MPD16 */
+	CONTROL_PORT(0x09e8, 0x0062, 0, "%s Control"),
+	PORT_INFO(0x09e8, 0x0062, 1, "%s MIDI", 0,
+		SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+		SNDRV_SEQ_PORT_TYPE_HARDWARE),
+	/* Access Music Virus TI */
+	EXTERNAL_PORT(0x133e, 0x0815, 0, "%s MIDI"),
+	PORT_INFO(0x133e, 0x0815, 1, "%s Synth", 0,
+		SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+		SNDRV_SEQ_PORT_TYPE_HARDWARE |
+		SNDRV_SEQ_PORT_TYPE_SYNTHESIZER),
+};
+
+static struct port_info *find_port_info(struct snd_usb_midi *umidi, int number)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(snd_usbmidi_port_info); ++i) {
+		if (snd_usbmidi_port_info[i].id == umidi->usb_id &&
+		    snd_usbmidi_port_info[i].port == number)
+			return &snd_usbmidi_port_info[i];
+	}
+	return NULL;
+}
+
+static void snd_usbmidi_get_port_info(struct snd_rawmidi *rmidi, int number,
+				      struct snd_seq_port_info *seq_port_info)
+{
+	struct snd_usb_midi *umidi = rmidi->private_data;
+	struct port_info *port_info;
+
+	/* TODO: read port flags from descriptors */
+	port_info = find_port_info(umidi, number);
+	if (port_info) {
+		seq_port_info->type = port_info->seq_flags;
+		seq_port_info->midi_voices = port_info->voices;
+	}
+}
+
+static void snd_usbmidi_init_substream(struct snd_usb_midi *umidi,
+				       int stream, int number,
+				       struct snd_rawmidi_substream **rsubstream)
+{
+	struct port_info *port_info;
+	const char *name_format;
+
+	struct snd_rawmidi_substream *substream =
+		snd_usbmidi_find_substream(umidi, stream, number);
+	if (!substream) {
+		dev_err(&umidi->dev->dev, "substream %d:%d not found\n", stream,
+			number);
+		return;
+	}
+
+	/* TODO: read port name from jack descriptor */
+	port_info = find_port_info(umidi, number);
+	name_format = port_info ? port_info->name : "%s MIDI %d";
+	snprintf(substream->name, sizeof(substream->name),
+		 name_format, umidi->card->shortname, number + 1);
+
+	*rsubstream = substream;
+}
+
+/*
+ * Creates the endpoints and their ports.
+ */
+static int snd_usbmidi_create_endpoints(struct snd_usb_midi *umidi,
+					struct snd_usb_midi_endpoint_info *endpoints)
+{
+	int i, j, err;
+	int out_ports = 0, in_ports = 0;
+
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		if (endpoints[i].out_cables) {
+			err = snd_usbmidi_out_endpoint_create(umidi,
+							      &endpoints[i],
+							      &umidi->endpoints[i]);
+			if (err < 0)
+				return err;
+		}
+		if (endpoints[i].in_cables) {
+			err = snd_usbmidi_in_endpoint_create(umidi,
+							     &endpoints[i],
+							     &umidi->endpoints[i]);
+			if (err < 0)
+				return err;
+		}
+
+		for (j = 0; j < 0x10; ++j) {
+			if (endpoints[i].out_cables & (1 << j)) {
+				snd_usbmidi_init_substream(umidi,
+							   SNDRV_RAWMIDI_STREAM_OUTPUT,
+							   out_ports,
+							   &umidi->endpoints[i].out->ports[j].substream);
+				++out_ports;
+			}
+			if (endpoints[i].in_cables & (1 << j)) {
+				snd_usbmidi_init_substream(umidi,
+							   SNDRV_RAWMIDI_STREAM_INPUT,
+							   in_ports,
+							   &umidi->endpoints[i].in->ports[j].substream);
+				++in_ports;
+			}
+		}
+	}
+	dev_dbg(&umidi->dev->dev, "created %d output and %d input ports\n",
+		    out_ports, in_ports);
+	return 0;
+}
+
+static struct usb_ms_endpoint_descriptor *find_usb_ms_endpoint_descriptor(
+					struct usb_host_endpoint *hostep)
+{
+	unsigned char *extra = hostep->extra;
+	int extralen = hostep->extralen;
+
+	while (extralen > 3) {
+		struct usb_ms_endpoint_descriptor *ms_ep =
+				(struct usb_ms_endpoint_descriptor *)extra;
+
+		if (ms_ep->bLength > 3 &&
+		    ms_ep->bDescriptorType == USB_DT_CS_ENDPOINT &&
+		    ms_ep->bDescriptorSubtype == UAC_MS_GENERAL)
+			return ms_ep;
+		if (!extra[0])
+			break;
+		extralen -= extra[0];
+		extra += extra[0];
+	}
+	return NULL;
+}
+
+/*
+ * Returns MIDIStreaming device capabilities.
+ */
+static int snd_usbmidi_get_ms_info(struct snd_usb_midi *umidi,
+				   struct snd_usb_midi_endpoint_info *endpoints)
+{
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	struct usb_interface_descriptor *intfd;
+	struct usb_ms_header_descriptor *ms_header;
+	struct usb_host_endpoint *hostep;
+	struct usb_endpoint_descriptor *ep;
+	struct usb_ms_endpoint_descriptor *ms_ep;
+	int i, epidx;
+
+	intf = umidi->iface;
+	if (!intf)
+		return -ENXIO;
+	hostif = &intf->altsetting[0];
+	intfd = get_iface_desc(hostif);
+	ms_header = (struct usb_ms_header_descriptor *)hostif->extra;
+	if (hostif->extralen >= 7 &&
+	    ms_header->bLength >= 7 &&
+	    ms_header->bDescriptorType == USB_DT_CS_INTERFACE &&
+	    ms_header->bDescriptorSubtype == UAC_HEADER)
+		dev_dbg(&umidi->dev->dev, "MIDIStreaming version %02x.%02x\n",
+			    ms_header->bcdMSC[1], ms_header->bcdMSC[0]);
+	else
+		dev_warn(&umidi->dev->dev,
+			 "MIDIStreaming interface descriptor not found\n");
+
+	epidx = 0;
+	for (i = 0; i < intfd->bNumEndpoints; ++i) {
+		hostep = &hostif->endpoint[i];
+		ep = get_ep_desc(hostep);
+		if (!usb_endpoint_xfer_bulk(ep) && !usb_endpoint_xfer_int(ep))
+			continue;
+		ms_ep = find_usb_ms_endpoint_descriptor(hostep);
+		if (!ms_ep)
+			continue;
+		if (ms_ep->bLength <= sizeof(*ms_ep))
+			continue;
+		if (ms_ep->bNumEmbMIDIJack > 0x10)
+			continue;
+		if (ms_ep->bLength < sizeof(*ms_ep) + ms_ep->bNumEmbMIDIJack)
+			continue;
+		if (usb_endpoint_dir_out(ep)) {
+			if (endpoints[epidx].out_ep) {
+				if (++epidx >= MIDI_MAX_ENDPOINTS) {
+					dev_warn(&umidi->dev->dev,
+						 "too many endpoints\n");
+					break;
+				}
+			}
+			endpoints[epidx].out_ep = usb_endpoint_num(ep);
+			if (usb_endpoint_xfer_int(ep))
+				endpoints[epidx].out_interval = ep->bInterval;
+			else if (snd_usb_get_speed(umidi->dev) == USB_SPEED_LOW)
+				/*
+				 * Low speed bulk transfers don't exist, so
+				 * force interrupt transfers for devices like
+				 * ESI MIDI Mate that try to use them anyway.
+				 */
+				endpoints[epidx].out_interval = 1;
+			endpoints[epidx].out_cables =
+				(1 << ms_ep->bNumEmbMIDIJack) - 1;
+			dev_dbg(&umidi->dev->dev, "EP %02X: %d jack(s)\n",
+				ep->bEndpointAddress, ms_ep->bNumEmbMIDIJack);
+		} else {
+			if (endpoints[epidx].in_ep) {
+				if (++epidx >= MIDI_MAX_ENDPOINTS) {
+					dev_warn(&umidi->dev->dev,
+						 "too many endpoints\n");
+					break;
+				}
+			}
+			endpoints[epidx].in_ep = usb_endpoint_num(ep);
+			if (usb_endpoint_xfer_int(ep))
+				endpoints[epidx].in_interval = ep->bInterval;
+			else if (snd_usb_get_speed(umidi->dev) == USB_SPEED_LOW)
+				endpoints[epidx].in_interval = 1;
+			endpoints[epidx].in_cables =
+				(1 << ms_ep->bNumEmbMIDIJack) - 1;
+			dev_dbg(&umidi->dev->dev, "EP %02X: %d jack(s)\n",
+				ep->bEndpointAddress, ms_ep->bNumEmbMIDIJack);
+		}
+	}
+	return 0;
+}
+
+static int roland_load_info(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_info *info)
+{
+	static const char *const names[] = { "High Load", "Light Load" };
+
+	return snd_ctl_enum_info(info, 1, 2, names);
+}
+
+static int roland_load_get(struct snd_kcontrol *kcontrol,
+			   struct snd_ctl_elem_value *value)
+{
+	value->value.enumerated.item[0] = kcontrol->private_value;
+	return 0;
+}
+
+static int roland_load_put(struct snd_kcontrol *kcontrol,
+			   struct snd_ctl_elem_value *value)
+{
+	struct snd_usb_midi *umidi = kcontrol->private_data;
+	int changed;
+
+	if (value->value.enumerated.item[0] > 1)
+		return -EINVAL;
+	mutex_lock(&umidi->mutex);
+	changed = value->value.enumerated.item[0] != kcontrol->private_value;
+	if (changed)
+		kcontrol->private_value = value->value.enumerated.item[0];
+	mutex_unlock(&umidi->mutex);
+	return changed;
+}
+
+static const struct snd_kcontrol_new roland_load_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "MIDI Input Mode",
+	.info = roland_load_info,
+	.get = roland_load_get,
+	.put = roland_load_put,
+	.private_value = 1,
+};
+
+/*
+ * On Roland devices, use the second alternate setting to be able to use
+ * the interrupt input endpoint.
+ */
+static void snd_usbmidi_switch_roland_altsetting(struct snd_usb_midi *umidi)
+{
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	struct usb_interface_descriptor *intfd;
+
+	intf = umidi->iface;
+	if (!intf || intf->num_altsetting != 2)
+		return;
+
+	hostif = &intf->altsetting[1];
+	intfd = get_iface_desc(hostif);
+       /* If either or both of the endpoints support interrupt transfer,
+        * then use the alternate setting
+        */
+	if (intfd->bNumEndpoints != 2 ||
+	    !((get_endpoint(hostif, 0)->bmAttributes &
+	       USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT ||
+	      (get_endpoint(hostif, 1)->bmAttributes &
+	       USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT))
+		return;
+
+	dev_dbg(&umidi->dev->dev, "switching to altsetting %d with int ep\n",
+		    intfd->bAlternateSetting);
+	usb_set_interface(umidi->dev, intfd->bInterfaceNumber,
+			  intfd->bAlternateSetting);
+
+	umidi->roland_load_ctl = snd_ctl_new1(&roland_load_ctl, umidi);
+	if (snd_ctl_add(umidi->card, umidi->roland_load_ctl) < 0)
+		umidi->roland_load_ctl = NULL;
+}
+
+/*
+ * Try to find any usable endpoints in the interface.
+ */
+static int snd_usbmidi_detect_endpoints(struct snd_usb_midi *umidi,
+					struct snd_usb_midi_endpoint_info *endpoint,
+					int max_endpoints)
+{
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	struct usb_interface_descriptor *intfd;
+	struct usb_endpoint_descriptor *epd;
+	int i, out_eps = 0, in_eps = 0;
+
+	if (USB_ID_VENDOR(umidi->usb_id) == 0x0582)
+		snd_usbmidi_switch_roland_altsetting(umidi);
+
+	if (endpoint[0].out_ep || endpoint[0].in_ep)
+		return 0;
+
+	intf = umidi->iface;
+	if (!intf || intf->num_altsetting < 1)
+		return -ENOENT;
+	hostif = intf->cur_altsetting;
+	intfd = get_iface_desc(hostif);
+
+	for (i = 0; i < intfd->bNumEndpoints; ++i) {
+		epd = get_endpoint(hostif, i);
+		if (!usb_endpoint_xfer_bulk(epd) &&
+		    !usb_endpoint_xfer_int(epd))
+			continue;
+		if (out_eps < max_endpoints &&
+		    usb_endpoint_dir_out(epd)) {
+			endpoint[out_eps].out_ep = usb_endpoint_num(epd);
+			if (usb_endpoint_xfer_int(epd))
+				endpoint[out_eps].out_interval = epd->bInterval;
+			++out_eps;
+		}
+		if (in_eps < max_endpoints &&
+		    usb_endpoint_dir_in(epd)) {
+			endpoint[in_eps].in_ep = usb_endpoint_num(epd);
+			if (usb_endpoint_xfer_int(epd))
+				endpoint[in_eps].in_interval = epd->bInterval;
+			++in_eps;
+		}
+	}
+	return (out_eps || in_eps) ? 0 : -ENOENT;
+}
+
+/*
+ * Detects the endpoints for one-port-per-endpoint protocols.
+ */
+static int snd_usbmidi_detect_per_port_endpoints(struct snd_usb_midi *umidi,
+						 struct snd_usb_midi_endpoint_info *endpoints)
+{
+	int err, i;
+
+	err = snd_usbmidi_detect_endpoints(umidi, endpoints, MIDI_MAX_ENDPOINTS);
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		if (endpoints[i].out_ep)
+			endpoints[i].out_cables = 0x0001;
+		if (endpoints[i].in_ep)
+			endpoints[i].in_cables = 0x0001;
+	}
+	return err;
+}
+
+/*
+ * Detects the endpoints and ports of Yamaha devices.
+ */
+static int snd_usbmidi_detect_yamaha(struct snd_usb_midi *umidi,
+				     struct snd_usb_midi_endpoint_info *endpoint)
+{
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	struct usb_interface_descriptor *intfd;
+	uint8_t *cs_desc;
+
+	intf = umidi->iface;
+	if (!intf)
+		return -ENOENT;
+	hostif = intf->altsetting;
+	intfd = get_iface_desc(hostif);
+	if (intfd->bNumEndpoints < 1)
+		return -ENOENT;
+
+	/*
+	 * For each port there is one MIDI_IN/OUT_JACK descriptor, not
+	 * necessarily with any useful contents.  So simply count 'em.
+	 */
+	for (cs_desc = hostif->extra;
+	     cs_desc < hostif->extra + hostif->extralen && cs_desc[0] >= 2;
+	     cs_desc += cs_desc[0]) {
+		if (cs_desc[1] == USB_DT_CS_INTERFACE) {
+			if (cs_desc[2] == UAC_MIDI_IN_JACK)
+				endpoint->in_cables =
+					(endpoint->in_cables << 1) | 1;
+			else if (cs_desc[2] == UAC_MIDI_OUT_JACK)
+				endpoint->out_cables =
+					(endpoint->out_cables << 1) | 1;
+		}
+	}
+	if (!endpoint->in_cables && !endpoint->out_cables)
+		return -ENOENT;
+
+	return snd_usbmidi_detect_endpoints(umidi, endpoint, 1);
+}
+
+/*
+ * Detects the endpoints and ports of Roland devices.
+ */
+static int snd_usbmidi_detect_roland(struct snd_usb_midi *umidi,
+				     struct snd_usb_midi_endpoint_info *endpoint)
+{
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	u8 *cs_desc;
+
+	intf = umidi->iface;
+	if (!intf)
+		return -ENOENT;
+	hostif = intf->altsetting;
+	/*
+	 * Some devices have a descriptor <06 24 F1 02 <inputs> <outputs>>,
+	 * some have standard class descriptors, or both kinds, or neither.
+	 */
+	for (cs_desc = hostif->extra;
+	     cs_desc < hostif->extra + hostif->extralen && cs_desc[0] >= 2;
+	     cs_desc += cs_desc[0]) {
+		if (cs_desc[0] >= 6 &&
+		    cs_desc[1] == USB_DT_CS_INTERFACE &&
+		    cs_desc[2] == 0xf1 &&
+		    cs_desc[3] == 0x02) {
+			if (cs_desc[4] > 0x10 || cs_desc[5] > 0x10)
+				continue;
+			endpoint->in_cables  = (1 << cs_desc[4]) - 1;
+			endpoint->out_cables = (1 << cs_desc[5]) - 1;
+			return snd_usbmidi_detect_endpoints(umidi, endpoint, 1);
+		} else if (cs_desc[0] >= 7 &&
+			   cs_desc[1] == USB_DT_CS_INTERFACE &&
+			   cs_desc[2] == UAC_HEADER) {
+			return snd_usbmidi_get_ms_info(umidi, endpoint);
+		}
+	}
+
+	return -ENODEV;
+}
+
+/*
+ * Creates the endpoints and their ports for Midiman devices.
+ */
+static int snd_usbmidi_create_endpoints_midiman(struct snd_usb_midi *umidi,
+						struct snd_usb_midi_endpoint_info *endpoint)
+{
+	struct snd_usb_midi_endpoint_info ep_info;
+	struct usb_interface *intf;
+	struct usb_host_interface *hostif;
+	struct usb_interface_descriptor *intfd;
+	struct usb_endpoint_descriptor *epd;
+	int cable, err;
+
+	intf = umidi->iface;
+	if (!intf)
+		return -ENOENT;
+	hostif = intf->altsetting;
+	intfd = get_iface_desc(hostif);
+	/*
+	 * The various MidiSport devices have more or less random endpoint
+	 * numbers, so we have to identify the endpoints by their index in
+	 * the descriptor array, like the driver for that other OS does.
+	 *
+	 * There is one interrupt input endpoint for all input ports, one
+	 * bulk output endpoint for even-numbered ports, and one for odd-
+	 * numbered ports.  Both bulk output endpoints have corresponding
+	 * input bulk endpoints (at indices 1 and 3) which aren't used.
+	 */
+	if (intfd->bNumEndpoints < (endpoint->out_cables > 0x0001 ? 5 : 3)) {
+		dev_dbg(&umidi->dev->dev, "not enough endpoints\n");
+		return -ENOENT;
+	}
+
+	epd = get_endpoint(hostif, 0);
+	if (!usb_endpoint_dir_in(epd) || !usb_endpoint_xfer_int(epd)) {
+		dev_dbg(&umidi->dev->dev, "endpoint[0] isn't interrupt\n");
+		return -ENXIO;
+	}
+	epd = get_endpoint(hostif, 2);
+	if (!usb_endpoint_dir_out(epd) || !usb_endpoint_xfer_bulk(epd)) {
+		dev_dbg(&umidi->dev->dev, "endpoint[2] isn't bulk output\n");
+		return -ENXIO;
+	}
+	if (endpoint->out_cables > 0x0001) {
+		epd = get_endpoint(hostif, 4);
+		if (!usb_endpoint_dir_out(epd) ||
+		    !usb_endpoint_xfer_bulk(epd)) {
+			dev_dbg(&umidi->dev->dev,
+				"endpoint[4] isn't bulk output\n");
+			return -ENXIO;
+		}
+	}
+
+	ep_info.out_ep = get_endpoint(hostif, 2)->bEndpointAddress &
+		USB_ENDPOINT_NUMBER_MASK;
+	ep_info.out_interval = 0;
+	ep_info.out_cables = endpoint->out_cables & 0x5555;
+	err = snd_usbmidi_out_endpoint_create(umidi, &ep_info,
+					      &umidi->endpoints[0]);
+	if (err < 0)
+		return err;
+
+	ep_info.in_ep = get_endpoint(hostif, 0)->bEndpointAddress &
+		USB_ENDPOINT_NUMBER_MASK;
+	ep_info.in_interval = get_endpoint(hostif, 0)->bInterval;
+	ep_info.in_cables = endpoint->in_cables;
+	err = snd_usbmidi_in_endpoint_create(umidi, &ep_info,
+					     &umidi->endpoints[0]);
+	if (err < 0)
+		return err;
+
+	if (endpoint->out_cables > 0x0001) {
+		ep_info.out_ep = get_endpoint(hostif, 4)->bEndpointAddress &
+			USB_ENDPOINT_NUMBER_MASK;
+		ep_info.out_cables = endpoint->out_cables & 0xaaaa;
+		err = snd_usbmidi_out_endpoint_create(umidi, &ep_info,
+						      &umidi->endpoints[1]);
+		if (err < 0)
+			return err;
+	}
+
+	for (cable = 0; cable < 0x10; ++cable) {
+		if (endpoint->out_cables & (1 << cable))
+			snd_usbmidi_init_substream(umidi,
+						   SNDRV_RAWMIDI_STREAM_OUTPUT,
+						   cable,
+						   &umidi->endpoints[cable & 1].out->ports[cable].substream);
+		if (endpoint->in_cables & (1 << cable))
+			snd_usbmidi_init_substream(umidi,
+						   SNDRV_RAWMIDI_STREAM_INPUT,
+						   cable,
+						   &umidi->endpoints[0].in->ports[cable].substream);
+	}
+	return 0;
+}
+
+static const struct snd_rawmidi_global_ops snd_usbmidi_ops = {
+	.get_port_info = snd_usbmidi_get_port_info,
+};
+
+static int snd_usbmidi_create_rawmidi(struct snd_usb_midi *umidi,
+				      int out_ports, int in_ports)
+{
+	struct snd_rawmidi *rmidi;
+	int err;
+
+	err = snd_rawmidi_new(umidi->card, "USB MIDI",
+			      umidi->next_midi_device++,
+			      out_ports, in_ports, &rmidi);
+	if (err < 0)
+		return err;
+	strcpy(rmidi->name, umidi->card->shortname);
+	rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
+			    SNDRV_RAWMIDI_INFO_INPUT |
+			    SNDRV_RAWMIDI_INFO_DUPLEX;
+	rmidi->ops = &snd_usbmidi_ops;
+	rmidi->private_data = umidi;
+	rmidi->private_free = snd_usbmidi_rawmidi_free;
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+			    &snd_usbmidi_output_ops);
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+			    &snd_usbmidi_input_ops);
+
+	umidi->rmidi = rmidi;
+	return 0;
+}
+
+/*
+ * Temporarily stop input.
+ */
+void snd_usbmidi_input_stop(struct list_head *p)
+{
+	struct snd_usb_midi *umidi;
+	unsigned int i, j;
+
+	umidi = list_entry(p, struct snd_usb_midi, list);
+	if (!umidi->input_running)
+		return;
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
+		if (ep->in)
+			for (j = 0; j < INPUT_URBS; ++j)
+				usb_kill_urb(ep->in->urbs[j]);
+	}
+	umidi->input_running = 0;
+}
+EXPORT_SYMBOL(snd_usbmidi_input_stop);
+
+static void snd_usbmidi_input_start_ep(struct snd_usb_midi *umidi,
+				       struct snd_usb_midi_in_endpoint *ep)
+{
+	unsigned int i;
+	unsigned long flags;
+
+	if (!ep)
+		return;
+	for (i = 0; i < INPUT_URBS; ++i) {
+		struct urb *urb = ep->urbs[i];
+		spin_lock_irqsave(&umidi->disc_lock, flags);
+		if (!atomic_read(&urb->use_count)) {
+			urb->dev = ep->umidi->dev;
+			snd_usbmidi_submit_urb(urb, GFP_ATOMIC);
+		}
+		spin_unlock_irqrestore(&umidi->disc_lock, flags);
+	}
+}
+
+/*
+ * Resume input after a call to snd_usbmidi_input_stop().
+ */
+void snd_usbmidi_input_start(struct list_head *p)
+{
+	struct snd_usb_midi *umidi;
+	int i;
+
+	umidi = list_entry(p, struct snd_usb_midi, list);
+	if (umidi->input_running || !umidi->opened[1])
+		return;
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i)
+		snd_usbmidi_input_start_ep(umidi, umidi->endpoints[i].in);
+	umidi->input_running = 1;
+}
+EXPORT_SYMBOL(snd_usbmidi_input_start);
+
+/*
+ * Prepare for suspend. Typically called from the USB suspend callback.
+ */
+void snd_usbmidi_suspend(struct list_head *p)
+{
+	struct snd_usb_midi *umidi;
+
+	umidi = list_entry(p, struct snd_usb_midi, list);
+	mutex_lock(&umidi->mutex);
+	snd_usbmidi_input_stop(p);
+	mutex_unlock(&umidi->mutex);
+}
+EXPORT_SYMBOL(snd_usbmidi_suspend);
+
+/*
+ * Resume. Typically called from the USB resume callback.
+ */
+void snd_usbmidi_resume(struct list_head *p)
+{
+	struct snd_usb_midi *umidi;
+
+	umidi = list_entry(p, struct snd_usb_midi, list);
+	mutex_lock(&umidi->mutex);
+	snd_usbmidi_input_start(p);
+	mutex_unlock(&umidi->mutex);
+}
+EXPORT_SYMBOL(snd_usbmidi_resume);
+
+/*
+ * Creates and registers everything needed for a MIDI streaming interface.
+ */
+int __snd_usbmidi_create(struct snd_card *card,
+			 struct usb_interface *iface,
+			 struct list_head *midi_list,
+			 const struct snd_usb_audio_quirk *quirk,
+			 unsigned int usb_id)
+{
+	struct snd_usb_midi *umidi;
+	struct snd_usb_midi_endpoint_info endpoints[MIDI_MAX_ENDPOINTS];
+	int out_ports, in_ports;
+	int i, err;
+
+	umidi = kzalloc(sizeof(*umidi), GFP_KERNEL);
+	if (!umidi)
+		return -ENOMEM;
+	umidi->dev = interface_to_usbdev(iface);
+	umidi->card = card;
+	umidi->iface = iface;
+	umidi->quirk = quirk;
+	umidi->usb_protocol_ops = &snd_usbmidi_standard_ops;
+	spin_lock_init(&umidi->disc_lock);
+	init_rwsem(&umidi->disc_rwsem);
+	mutex_init(&umidi->mutex);
+	if (!usb_id)
+		usb_id = USB_ID(le16_to_cpu(umidi->dev->descriptor.idVendor),
+			       le16_to_cpu(umidi->dev->descriptor.idProduct));
+	umidi->usb_id = usb_id;
+	timer_setup(&umidi->error_timer, snd_usbmidi_error_timer, 0);
+
+	/* detect the endpoint(s) to use */
+	memset(endpoints, 0, sizeof(endpoints));
+	switch (quirk ? quirk->type : QUIRK_MIDI_STANDARD_INTERFACE) {
+	case QUIRK_MIDI_STANDARD_INTERFACE:
+		err = snd_usbmidi_get_ms_info(umidi, endpoints);
+		if (umidi->usb_id == USB_ID(0x0763, 0x0150)) /* M-Audio Uno */
+			umidi->usb_protocol_ops =
+				&snd_usbmidi_maudio_broken_running_status_ops;
+		break;
+	case QUIRK_MIDI_US122L:
+		umidi->usb_protocol_ops = &snd_usbmidi_122l_ops;
+		fallthrough;
+	case QUIRK_MIDI_FIXED_ENDPOINT:
+		memcpy(&endpoints[0], quirk->data,
+		       sizeof(struct snd_usb_midi_endpoint_info));
+		err = snd_usbmidi_detect_endpoints(umidi, &endpoints[0], 1);
+		break;
+	case QUIRK_MIDI_YAMAHA:
+		err = snd_usbmidi_detect_yamaha(umidi, &endpoints[0]);
+		break;
+	case QUIRK_MIDI_ROLAND:
+		err = snd_usbmidi_detect_roland(umidi, &endpoints[0]);
+		break;
+	case QUIRK_MIDI_MIDIMAN:
+		umidi->usb_protocol_ops = &snd_usbmidi_midiman_ops;
+		memcpy(&endpoints[0], quirk->data,
+		       sizeof(struct snd_usb_midi_endpoint_info));
+		err = 0;
+		break;
+	case QUIRK_MIDI_NOVATION:
+		umidi->usb_protocol_ops = &snd_usbmidi_novation_ops;
+		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+		break;
+	case QUIRK_MIDI_RAW_BYTES:
+		umidi->usb_protocol_ops = &snd_usbmidi_raw_ops;
+		/*
+		 * Interface 1 contains isochronous endpoints, but with the same
+		 * numbers as in interface 0.  Since it is interface 1 that the
+		 * USB core has most recently seen, these descriptors are now
+		 * associated with the endpoint numbers.  This will foul up our
+		 * attempts to submit bulk/interrupt URBs to the endpoints in
+		 * interface 0, so we have to make sure that the USB core looks
+		 * again at interface 0 by calling usb_set_interface() on it.
+		 */
+		if (umidi->usb_id == USB_ID(0x07fd, 0x0001)) /* MOTU Fastlane */
+			usb_set_interface(umidi->dev, 0, 0);
+		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+		break;
+	case QUIRK_MIDI_EMAGIC:
+		umidi->usb_protocol_ops = &snd_usbmidi_emagic_ops;
+		memcpy(&endpoints[0], quirk->data,
+		       sizeof(struct snd_usb_midi_endpoint_info));
+		err = snd_usbmidi_detect_endpoints(umidi, &endpoints[0], 1);
+		break;
+	case QUIRK_MIDI_CME:
+		umidi->usb_protocol_ops = &snd_usbmidi_cme_ops;
+		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+		break;
+	case QUIRK_MIDI_AKAI:
+		umidi->usb_protocol_ops = &snd_usbmidi_akai_ops;
+		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+		/* endpoint 1 is input-only */
+		endpoints[1].out_cables = 0;
+		break;
+	case QUIRK_MIDI_FTDI:
+		umidi->usb_protocol_ops = &snd_usbmidi_ftdi_ops;
+
+		/* set baud rate to 31250 (48 MHz / 16 / 96) */
+		err = usb_control_msg(umidi->dev, usb_sndctrlpipe(umidi->dev, 0),
+				      3, 0x40, 0x60, 0, NULL, 0, 1000);
+		if (err < 0)
+			break;
+
+		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+		break;
+	case QUIRK_MIDI_CH345:
+		umidi->usb_protocol_ops = &snd_usbmidi_ch345_broken_sysex_ops;
+		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+		break;
+	default:
+		dev_err(&umidi->dev->dev, "invalid quirk type %d\n",
+			quirk->type);
+		err = -ENXIO;
+		break;
+	}
+	if (err < 0)
+		goto free_midi;
+
+	/* create rawmidi device */
+	out_ports = 0;
+	in_ports = 0;
+	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
+		out_ports += hweight16(endpoints[i].out_cables);
+		in_ports += hweight16(endpoints[i].in_cables);
+	}
+	err = snd_usbmidi_create_rawmidi(umidi, out_ports, in_ports);
+	if (err < 0)
+		goto free_midi;
+
+	/* create endpoint/port structures */
+	if (quirk && quirk->type == QUIRK_MIDI_MIDIMAN)
+		err = snd_usbmidi_create_endpoints_midiman(umidi, &endpoints[0]);
+	else
+		err = snd_usbmidi_create_endpoints(umidi, endpoints);
+	if (err < 0)
+		goto exit;
+
+	usb_autopm_get_interface_no_resume(umidi->iface);
+
+	list_add_tail(&umidi->list, midi_list);
+	return 0;
+
+free_midi:
+	kfree(umidi);
+exit:
+	return err;
+}
+EXPORT_SYMBOL(__snd_usbmidi_create);