ALSA: usb-audio: refactor code

Clean up the usb audio driver by factoring out a lot of functions to
separate files. Code for procfs, quirks, urbs, format parsers etc all
got a new home now.

Moved almost all special quirk handling to quirks.c and introduced new
generic functions to handle them, so the exceptions do not pollute the
whole driver.

Renamed usbaudio.c to card.c because this is what it actually does now.
Renamed usbmidi.c to midi.c for namespace clarity.
Removed more things from usbaudio.h.

The non-standard drivers were adopted accordingly.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 2069 insertions, 0 deletions

diff --git a/sound/usb/midi.c b/sound/usb/midi.c
new file mode 100644
index 00000000000..c6ee4a18e51
--- /dev/null
+++ b/sound/usb/midi.c
@@ -0,0 +1,2069 @@
+/*
+ * 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 <sound/core.h>
+#include <sound/control.h>
+#include <sound/rawmidi.h>
+#include <sound/asequencer.h>
+#include "usbaudio.h"
+#include "midi.h"
+#include "helper.h"
+
+/*
+ * define this to log all USB packets
+ */
+/* #define DUMP_PACKETS */
+
+/*
+ * how long to wait after some USB errors, so that khubd 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[0];
+} __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;
+	struct usb_protocol_ops* usb_protocol_ops;
+	struct list_head list;
+	struct timer_list error_timer;
+	spinlock_t disc_lock;
+	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;
+	unsigned char disconnected;
+
+	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 tasklet_struct tasklet;
+	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;
+	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)
+		snd_printk(KERN_ERR "usb_submit_urb: %d\n", err);
+	return err;
+}
+
+/*
+ * Error handling for URB completion functions.
+ */
+static int snd_usbmidi_urb_error(int status)
+{
+	switch (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:
+		snd_printk(KERN_ERR "urb status %d\n", 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) {
+		snd_printd("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(" %02x", *data);
+	printk(" ]\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->status);
+		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;
+
+	spin_lock(&ep->buffer_lock);
+	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(&ep->buffer_lock);
+	if (urb->status < 0) {
+		int err = snd_usbmidi_urb_error(urb->status);
+		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_tasklet(unsigned long data)
+{
+	struct snd_usb_midi_out_endpoint* ep = (struct snd_usb_midi_out_endpoint *) data;
+
+	snd_usbmidi_do_output(ep);
+}
+
+/* called after transfers had been interrupted due to some USB error */
+static void snd_usbmidi_error_timer(unsigned long data)
+{
+	struct snd_usb_midi *umidi = (struct snd_usb_midi *)data;
+	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) {
+				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);
+		}
+}
+
+/*
+ * 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 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 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 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 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,
+};
+
+/*
+ * 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 struct usb_protocol_ops snd_usbmidi_novation_ops = {
+	.input = snd_usbmidi_novation_input,
+	.output = snd_usbmidi_novation_output,
+};
+
+/*
+ * "raw" protocol: used by the MOTU FastLane.
+ */
+
+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 struct usb_protocol_ops snd_usbmidi_raw_ops = {
+	.input = snd_usbmidi_raw_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;
+	count = snd_usb_get_speed(ep->umidi->dev) == USB_SPEED_HIGH ? 1 : 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, 9 - count);
+	urb->transfer_buffer_length = count;
+}
+
+static 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 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 void substream_open(struct snd_rawmidi_substream *substream, int open)
+{
+	struct snd_usb_midi* umidi = substream->rmidi->private_data;
+	struct snd_kcontrol *ctl;
+
+	mutex_lock(&umidi->mutex);
+	if (open) {
+		if (umidi->opened++ == 0 && 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);
+		}
+	} else {
+		if (--umidi->opened == 0 && 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);
+}
+
+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) {
+		snd_BUG();
+		return -ENXIO;
+	}
+	substream->runtime->private_data = port;
+	port->state = STATE_UNKNOWN;
+	substream_open(substream, 1);
+	return 0;
+}
+
+static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
+{
+	substream_open(substream, 0);
+	return 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 */
+			while (!snd_rawmidi_transmit_empty(substream))
+				snd_rawmidi_transmit_ack(substream, 1);
+			return;
+		}
+		tasklet_schedule(&port->ep->tasklet);
+	}
+}
+
+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);
+
+	/*
+	 * 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);
+	}
+	spin_unlock_irq(&ep->buffer_lock);
+}
+
+static int snd_usbmidi_input_open(struct snd_rawmidi_substream *substream)
+{
+	substream_open(substream, 1);
+	return 0;
+}
+
+static int snd_usbmidi_input_close(struct snd_rawmidi_substream *substream)
+{
+	substream_open(substream, 0);
+	return 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 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 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_buffer_free(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;
+
+	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]) {
+			snd_usbmidi_in_endpoint_delete(ep);
+			return -ENOMEM;
+		}
+	}
+	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_buffer_alloc(umidi->dev, length, GFP_KERNEL,
+					  &ep->urbs[i]->transfer_dma);
+		if (!buffer) {
+			snd_usbmidi_in_endpoint_delete(ep);
+			return -ENOMEM;
+		}
+		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;
+	}
+
+	rep->in = ep;
+	return 0;
+}
+
+/*
+ * Frees an output endpoint.
+ * May be called when ep hasn't been initialized completely.
+ */
+static void snd_usbmidi_out_endpoint_delete(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);
+	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)
+{
+	struc