[PATCH] MIDI driver for Behringer BCD2000 USB device

[Mario Kicherer <dev@kicherer.org>]

This patch adds initial support for the Behringer BCD2000 USB DJ controller.
At the moment, only the MIDI part of the device is working, i.e. knobs,
buttons and LEDs.

I also plan to add support for the audio part, but I assume that this will
require more effort than the rather simple MIDI interface. Progress can be
tracked at https://github.com/anyc/snd-usb-bcd2000.

Signed-off-by: Mario Kicherer <dev@kicherer.org>
---
 sound/usb/Kconfig           |  14 +
 sound/usb/Makefile          |   2 +-
 sound/usb/bcd2000/Makefile  |   3 +
 sound/usb/bcd2000/bcd2000.c | 629 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 647 insertions(+), 1 deletion(-)
 create mode 100644 sound/usb/bcd2000/Makefile
 create mode 100644 sound/usb/bcd2000/bcd2000.c

diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index de9408b..50af405 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -146,5 +146,19 @@ config SND_USB_HIFACE
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-usb-hiface.
 
+config SND_USB_BCD2000
+	tristate "Behringer BCD2000 MIDI driver"
+	select SND_HWDEP
+	select SND_RAWMIDI
+	help
+	  Say Y here to include MIDI support for the Behringer BCD2000 DJ
+	  controller.
+	  
+	  Audio support is still work-in-progress at
+	  https://github.com/anyc/snd-usb-bcd2000
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-usb-bcd2000.
+
 endif	# SND_USB
 
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index abe668f..2b92f0d 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -23,4 +23,4 @@ obj-$(CONFIG_SND_USB_UA101) += snd-usbmidi-lib.o
 obj-$(CONFIG_SND_USB_USX2Y) += snd-usbmidi-lib.o
 obj-$(CONFIG_SND_USB_US122L) += snd-usbmidi-lib.o
 
-obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/
+obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/ bcd2000/
diff --git a/sound/usb/bcd2000/Makefile b/sound/usb/bcd2000/Makefile
new file mode 100644
index 0000000..6540136
--- /dev/null
+++ b/sound/usb/bcd2000/Makefile
@@ -0,0 +1,3 @@
+snd-usb-bcd2000-y := bcd2000.o
+
+obj-$(CONFIG_SND_USB_BCD2000) += snd-usb-bcd2000.o
\ No newline at end of file
diff --git a/sound/usb/bcd2000/bcd2000.c b/sound/usb/bcd2000/bcd2000.c
new file mode 100644
index 0000000..100c39f
--- /dev/null
+++ b/sound/usb/bcd2000/bcd2000.c
@@ -0,0 +1,629 @@
+/*
+ * Behringer BCD2000 driver
+ *
+ *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it 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 program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#ifdef CONFIG_USB_DEBUG
+#define DEBUG	1
+#else
+#define DEBUG	0
+#endif
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/rawmidi.h>
+#include "../usbaudio.h"
+#include "../midi.h"
+
+#define DEVICE_NAME "Behringer BCD2000"
+#define DEVICE_SHORTNAME "bcd2000"
+
+#define PREFIX DEVICE_SHORTNAME ": "
+#define BUFSIZE 64
+
+static struct usb_device_id id_table [] = {
+	{ USB_DEVICE(0x1397, 0x00bd) },
+	{ },
+};
+MODULE_DEVICE_TABLE (usb, id_table);
+MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
+MODULE_DESCRIPTION("Behringer BCD2000 driver");
+MODULE_LICENSE("GPL");
+
+static int debug = 0;
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "enable debug output (default: 0)");
+
+static unsigned char set_led_prefix[] = {0x03, 0x00};
+
+static unsigned char bcd2000_init_sequence[] = {
+	0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
+	0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
+	0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
+	0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+	0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
+	0x18, 0xfa, 0x11, 0xff};
+
+struct bcd2000 {
+	struct usb_device *dev;
+	struct snd_card *card;
+	struct usb_interface *intf;
+	int card_index;
+	struct snd_pcm *pcm;
+	struct list_head midi_list;
+	spinlock_t lock;
+	struct mutex mutex;
+	
+	int midi_out_active;
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_substream *midi_receive_substream;
+	struct snd_rawmidi_substream *midi_out_substream;
+	
+	unsigned char midi_in_buf[BUFSIZE];
+	unsigned char midi_out_buf[BUFSIZE];
+	
+	unsigned char midi_cmd_buf[3];
+	unsigned char midi_cmd_offset;
+	
+	struct urb * midi_out_urb;
+	struct urb * midi_in_urb;
+};
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
+static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
+
+static DEFINE_MUTEX(devices_mutex);
+static unsigned int devices_used;
+static struct usb_driver bcd2000_driver;
+
+
+
+
+
+
+static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	struct bcd2000 *bcd2k = substream->rmidi->private_data;
+	
+	if (!bcd2k)
+		return;
+	
+	bcd2k->midi_receive_substream = up ? substream : NULL;
+}
+
+static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
+					const unsigned char *buf, int len)
+{
+	unsigned char length, cmd, buf_offset, tocopy;
+	int ret;
+	
+	if (!bcd2k->midi_receive_substream)
+		return;
+	
+	if (DEBUG || debug) {
+		printk(KERN_DEBUG PREFIX "received (%d bytes): ", len);
+		for (ret=0; ret < len; ret++) {
+			printk("%x ", buf[ret]);
+		}
+		printk("\n");
+	}
+	
+	if (len < 2)
+		return;
+	
+	/*
+	 * The BCD2000 sends MIDI commands with 2 or 3 bytes length. In case of
+	 * 2 bytes, the command is the same as before.
+	 *
+	 * Packet structure: mm nn oo (pp)
+	 *	mm: payload length
+	 *	nn: MIDI command or note
+	 *	oo: note or velocity
+	 *	pp: velocity
+	 */
+	
+	length = buf[0];
+	
+	/* ignore packets without payload, should not happen */
+	if (length == 0)
+		return;
+	
+	/*
+	 * The MIDI packets the BCD2000 sends can be arbitrarily truncated or
+	 * concatenated. Therefore, this loop accumulates the bytes from the
+	 * input buffer until a full valid MIDI packet is in the MIDI command
+	 * buffer "midi_cmd_buf".
+	 */
+	
+	buf_offset = 1;
+	while (buf_offset <= length) {
+		cmd = buf[buf_offset];
+		
+		if (bcd2k->midi_cmd_offset == 0 && cmd != 0x90 && cmd != 0xb0) {
+			/*
+			 * this is a 2-byte midi packet -> reuse command byte from
+			 * last midi packet
+			 */
+			bcd2k->midi_cmd_offset = 1;
+		}
+		
+		/* determine the number of bytes we want to copy this time */
+		tocopy = min( 3 - bcd2k->midi_cmd_offset, length - (buf_offset - 1));
+		
+		if (tocopy > 0) {
+			memcpy(&bcd2k->midi_cmd_buf[bcd2k->midi_cmd_offset],
+				&buf[buf_offset], tocopy);
+		} else
+			printk(KERN_ERR PREFIX "error parsing\n");
+		
+		bcd2k->midi_cmd_offset += tocopy;
+		buf_offset += tocopy;
+		
+		/* is our MIDI packet complete? */
+		if (bcd2k->midi_cmd_offset == 3) {
+			if (DEBUG || debug) {
+				printk(KERN_DEBUG PREFIX "send midi packet (%d bytes): ",
+						bcd2k->midi_cmd_offset);
+				for (ret=0;ret< bcd2k->midi_cmd_offset;ret++) {
+					printk("%x ", bcd2k->midi_cmd_buf[ret]);
+				}
+				printk("\n");
+			}
+			
+			/* send MIDI packet */
+			snd_rawmidi_receive(bcd2k->midi_receive_substream,
+						bcd2k->midi_cmd_buf, 3);
+			
+			bcd2k->midi_cmd_offset = 0;
+		}
+	}
+}
+
+static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
+{
+	struct bcd2000 * bcd2k = substream->rmidi->private_data;
+	if (bcd2k->midi_out_active) {
+		usb_free_urb(bcd2k->midi_out_urb);
+		bcd2k->midi_out_active = 0;
+	}
+	return 0;
+}
+
+static void bcd2000_midi_send(struct bcd2000 *bcd2k,
+				struct snd_rawmidi_substream *substream)
+{
+	int len, ret;
+	
+	/* copy the "set LED" command bytes */
+	memcpy(bcd2k->midi_out_buf, set_led_prefix, sizeof(set_led_prefix));
+	
+	/* get MIDI packet */
+	len = snd_rawmidi_transmit(substream, bcd2k->midi_out_buf + 3, BUFSIZE - 3);
+	
+	if (len <= 0)
+		return;
+	
+	/* set payload length */
+	bcd2k->midi_out_buf[2] = len;
+	bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
+	
+	if (DEBUG || debug) {
+		printk(KERN_DEBUG PREFIX "sending: ");
+		for (ret=0;ret< 3 + len;ret++) {
+			printk("%x ", bcd2k->midi_out_buf[ret]);
+		}
+		printk("\n");
+	}
+	
+	/* send packet to the BCD2000 */
+	ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
+	if (ret < 0) {
+		printk(KERN_ERR PREFIX
+			   "bcd2000_midi_send(%p): usb_submit_urb() failed,"
+			   "ret=%d, len=%d: ", substream, ret, len);
+		switch (ret) {
+			case -ENOMEM: printk("ENOMEM\n"); break;
+			case -ENODEV: printk("ENODEV\n"); break;
+			case -ENXIO: printk("ENXIO\n"); break;
+			case -EINVAL: printk("EINVAL\n"); break;
+			case -EAGAIN: printk("EAGAIN\n"); break;
+			case -EFBIG: printk("EFBIG\n"); break;
+			case -EPIPE: printk("EPIPE\n"); break;
+			case -EMSGSIZE: printk("EMSGSIZE\n"); break;
+			default: printk("\n");
+		}
+	} else {
+		bcd2k->midi_out_active = 1;
+	}
+}
+
+static void bcd2000_midi_output_done(struct urb* urb)
+{
+	struct bcd2000 * bcd2k = urb->context;
+	
+	bcd2k->midi_out_active = 0;
+	if (urb->status != 0) {
+		printk(KERN_ERR PREFIX "urb status: %d\n", urb->status);
+		return;
+	}
+	
+	if (!bcd2k->midi_out_substream)
+		return;
+	
+	bcd2000_midi_send(bcd2k, bcd2k->midi_out_substream);
+}
+
+static void bcd2000_command_reply_dispatch(struct urb* urb)
+{
+	int ret;
+	struct device *dev = &urb->dev->dev;
+	struct bcd2000 *bcd2k = urb->context;
+	
+	if (urb->status || !bcd2k) {
+		dev_warn(dev, "received urb->status = %i\n", urb->status);
+		return;
+	}
+	
+	if (urb->actual_length > 0)
+		bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer, urb->actual_length);
+	
+	bcd2k->midi_in_urb->actual_length = 0;
+	ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
+	if (ret < 0)
+		dev_err(dev, "unable to submit urb. OOM!?\n");
+}
+
+static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	struct bcd2000 *bcd2k = substream->rmidi->private_data;
+	
+	if (up) {
+		bcd2k->midi_out_substream = substream;
+		if (!bcd2k->midi_out_active)
+			bcd2000_midi_send(bcd2k, substream);
+	} else {
+		bcd2k->midi_out_substream = NULL;
+	}
+}
+
+static struct snd_rawmidi_ops bcd2000_midi_output =
+{
+	.open =    bcd2000_midi_output_open,
+	.close =   bcd2000_midi_output_close,
+	.trigger = bcd2000_midi_output_trigger,
+};
+
+static struct snd_rawmidi_ops bcd2000_midi_input =
+{
+	.open =    bcd2000_midi_input_open,
+	.close =   bcd2000_midi_input_close,
+	.trigger = bcd2000_midi_input_trigger,
+};
+
+static void bcd2000_init_device(struct bcd2000 * bcd2k) {
+	int ret;
+	
+	/* copy init sequence into buffer */
+	memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
+	bcd2k->midi_out_urb->transfer_buffer_length = 52;
+	
+	/* submit sequence */
+	ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
+	if (ret < 0) {
+		printk(KERN_ERR PREFIX
+				"bcd2000_init_device: usb_submit_urb() failed,"
+				"ret=%d: ", ret);
+		switch (ret) {
+			case -ENOMEM: printk("ENOMEM\n"); break;
+			case -ENODEV: printk("ENODEV\n"); break;
+			case -ENXIO: printk("ENXIO\n"); break;
+			case -EINVAL: printk("EINVAL\n"); break;
+			case -EAGAIN: printk("EAGAIN\n"); break;
+			case -EFBIG: printk("EFBIG\n"); break;
+			case -EPIPE: printk("EPIPE\n"); break;
+			case -EMSGSIZE: printk("EMSGSIZE\n"); break;
+			default: printk("\n");
+		}
+	} else {
+		bcd2k->midi_out_active = 1;
+	}
+	
+	/* send empty packet to enable button and controller events */
+	bcd2k->midi_in_urb->actual_length = 0;
+	ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
+}
+
+static void bcd2000_init_midi(struct bcd2000 * bcd2k) {
+	int ret;
+	struct snd_rawmidi *rmidi;
+	
+	ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
+					1, /* output */
+					1, /* input */
+					&rmidi);
+
+	if (ret < 0)
+		return;
+
+	strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
+
+	rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
+	rmidi->private_data = bcd2k;
+
+	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+					&bcd2000_midi_output);
+
+	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+					&bcd2000_midi_input);
+
+	bcd2k->rmidi = rmidi;
+	
+	bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
+	
+	usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
+				usb_rcvbulkpipe(bcd2k->dev, 0x81),
+				bcd2k->midi_in_buf, BUFSIZE,
+				bcd2000_command_reply_dispatch, bcd2k, 1);
+	
+	usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
+				usb_sndbulkpipe(bcd2k->dev, 0x1),
+				bcd2k->midi_out_buf, BUFSIZE,
+				bcd2000_midi_output_done, bcd2k, 1);
+	
+	bcd2000_init_device(bcd2k);
+}
+
+static void bcd2000_close_midi(struct bcd2000 * bcd2k) {
+	usb_free_urb(bcd2k->midi_out_urb);
+	usb_free_urb(bcd2k->midi_in_urb);
+}
+
+
+
+
+
+/*
+ * general part
+ */
+
+static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
+						struct usb_interface *interface)
+{
+	unsigned int i;
+	struct usb_interface *intf;
+	
+// 	mutex_lock(&ua->mutex);
+// 	free_stream_urbs(&ua->capture);
+// 	free_stream_urbs(&ua->playback);
+// 	mutex_unlock(&ua->mutex);
+// 	free_stream_buffers(ua, &ua->capture);
+// 	free_stream_buffers(ua, &ua->playback);
+	
+	for (i = 0; i < 1; ++i) {
+		mutex_lock(&bcd2k->mutex);
+		intf = bcd2k->intf;
+		bcd2k->intf = NULL;
+		mutex_unlock(&bcd2k->mutex);
+		if (intf) {
+			usb_set_intfdata(intf, NULL);
+			if (intf != interface)
+				usb_driver_release_interface(&bcd2000_driver,
+								intf);
+		}
+	}
+}
+
+static void bcd2000_card_free(struct snd_card *card)
+{
+// 	struct bcd2000 *bcd2k = card->private_data;
+// 	mutex_destroy(&ua->mutex);
+}
+
+static int bcd2000_probe(struct usb_interface *interface, const struct usb_device_id *usb_id)
+{
+	struct snd_card *card;
+	struct bcd2000 * bcd2k;
+	unsigned int card_index;
+	char usb_path[32];
+	int err;
+	
+	
+	mutex_lock(&devices_mutex);
+	
+	for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
+		if (enable[card_index] && !(devices_used & (1 << card_index)))
+			break;
+	if (card_index >= SNDRV_CARDS) {
+		mutex_unlock(&devices_mutex);
+		return -ENOENT;
+	}
+	err = snd_card_create(index[card_index], id[card_index], THIS_MODULE,
+					sizeof(*bcd2k), &card);
+	if (err < 0) {
+		mutex_unlock(&devices_mutex);
+		return err;
+	}
+	card->private_free = bcd2000_card_free;
+	bcd2k = card->private_data;
+	bcd2k->dev = interface_to_usbdev(interface);
+	bcd2k->card = card;
+	bcd2k->card_index = card_index;
+	INIT_LIST_HEAD(&bcd2k->midi_list);
+	spin_lock_init(&bcd2k->lock);
+	mutex_init(&bcd2k->mutex);
+	
+// 	INIT_LIST_HEAD(&bcd2k->ready_playback_urbs);
+// 	tasklet_init(&bcd2k->playback_tasklet,
+// 				playback_tasklet, (unsigned long)bcd2k);
+// 	init_waitqueue_head(&bcd2k->alsa_capture_wait);
+// 	init_waitqueue_head(&bcd2k->rate_feedback_wait);
+// 	init_waitqueue_head(&bcd2k->alsa_playback_wait);
+	
+	bcd2k->intf = interface;
+	
+	snd_card_set_dev(card, &interface->dev);
+	
+	strcpy(card->driver, DEVICE_NAME);
+	strcpy(card->shortname, DEVICE_SHORTNAME);
+	usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
+	snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
+		    DEVICE_NAME ", at %s, %s speed",
+				usb_path,
+				bcd2k->dev->speed == USB_SPEED_HIGH ? "high" : "full");
+	
+	printk(KERN_INFO PREFIX "%s", bcd2k->card->longname);
+	
+// 	err = alloc_stream_buffers(bcd2k, &bcd2k->capture);
+// 	if (err < 0)
+// 		goto probe_error;
+// 	err = alloc_stream_buffers(bcd2k, &bcd2k->playback);
+// 	if (err < 0)
+// 		goto probe_error;
+// 	
+// 	err = alloc_stream_urbs(bcd2k, &bcd2k->capture, capture_urb_complete);
+// 	if (err < 0)
+// 		goto probe_error;
+// 	err = alloc_stream_urbs(bcd2k, &bcd2k->playback, playback_urb_complete);
+// 	if (err < 0)
+// 		goto probe_error;
+// 	
+// 	err = snd_pcm_new(card, "bcd2000", 0, 1, 1, &bcd2k->pcm);
+// 	if (err < 0)
+// 		goto probe_error;
+// 	bcd2k->pcm->private_data = bcd2k;
+// 	strcpy(bcd2k->pcm->name, "bcd2000");
+// 	snd_pcm_set_ops(bcd2k->pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_pcm_ops);
+// 	snd_pcm_set_ops(bcd2k->pcm, SNDRV_PCM_STREAM_CAPTURE, &capture_pcm_ops);
+	
+// 	err = snd_usbmidi_create(card, bcd2k->intf,
+// 						&bcd2k->midi_list, &midi_quirk);
+// 	if (err < 0)
+// 		goto probe_error;
+	
+	
+	
+	bcd2000_init_midi(bcd2k);
+	
+	
+	err = snd_card_register(card);
+	if (err < 0)
+		goto probe_error;
+	
+	usb_set_intfdata(interface, bcd2k);
+	devices_used |= 1 << card_index;
+	
+	mutex_unlock(&devices_mutex);
+	return 0;
+	
+probe_error:
+	bcd2000_free_usb_related_resources(bcd2k, interface);
+	snd_card_free(card);
+	mutex_unlock(&devices_mutex);
+	return err;
+}
+
+static void bcd2000_disconnect(struct usb_interface *interface)
+{
+	struct bcd2000 *bcd2k = usb_get_intfdata(interface);
+	struct list_head *midi;
+	
+	if (!bcd2k)
+		return;
+	
+	bcd2000_close_midi(bcd2k);
+	
+	mutex_lock(&devices_mutex);
+	
+// 	set_bit(DISCONNECTED, &bcd2k->states);
+// 	wake_up(&bcd2k->rate_feedback_wait);
+	
+	/* make sure that userspace cannot create new requests */
+	snd_card_disconnect(bcd2k->card);
+	
+	/* make sure that there are no pending USB requests */
+	list_for_each(midi, &bcd2k->midi_list)
+		snd_usbmidi_disconnect(midi);
+	
+// 	abort_alsa_playback(bcd2k);
+// 	abort_alsa_capture(bcd2k);
+// 	mutex_lock(&bcd2k->mutex);
+// 	stop_usb_playback(bcd2k);
+// 	stop_usb_capture(bcd2k);
+// 	mutex_unlock(&bcd2k->mutex);
+	
+	bcd2000_free_usb_related_resources(bcd2k, interface);
+	
+	devices_used &= ~(1 << bcd2k->card_index);
+	
+	snd_card_free_when_closed(bcd2k->card);
+	
+	mutex_unlock(&devices_mutex);
+}
+
+static struct usb_driver bcd2000_driver = {
+	.name =	DEVICE_SHORTNAME,
+	.probe =	bcd2000_probe,
+	.disconnect =	bcd2000_disconnect,
+	.id_table =	id_table,
+};
+
+static int __init bcd2000_init(void)
+{
+	int retval = 0;
+	
+	retval = usb_register(&bcd2000_driver);
+	if (retval)
+		printk(KERN_INFO "usb_register failed. Error number %d", retval);
+	return retval;
+}
+
+static void __exit bcd2000_exit(void)
+{
+	usb_deregister(&bcd2000_driver);
+}
+
+module_init (bcd2000_init);
+module_exit (bcd2000_exit);
-- 
1.8.3.2