Staging: add line6 usb driver

This is an experimental Linux driver for the guitar amp, cab, and
effects modeller PODxt Pro by Line6 (and similar devices), supporting
the following features:

  - Reading/writing individual parameters
  - Reading/writing complete channel, effects setup, and amp setup data
  - Channel switching
  - Virtual MIDI interface
  - Tuner access
  - Playback/capture/mixer device for any  ALSA-compatible PCM audio
    application
  - Signal routing (record clean/processed  guitar signal, re-amping)

Moreover, preliminary support for the Variax Workbench is included.

From: Markus Grabner <grabner@icg.tugraz.at>
Cc: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1050 insertions, 0 deletions

diff --git a/drivers/staging/line6/driver.c b/drivers/staging/line6/driver.c
new file mode 100644
index 0000000..f20efa5
--- /dev/null
+++ b/drivers/staging/line6/driver.c
@@ -0,0 +1,1050 @@
+/*
+ * Line6 Linux USB driver - 0.8.0
+ *
+ * Copyright (C) 2004-2009 Markus Grabner (grabner@icg.tugraz.at)
+ *
+ *	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, version 2.
+ *
+ */
+
+#include "driver.h"
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+
+#include "audio.h"
+#include "capture.h"
+#include "control.h"
+#include "midi.h"
+#include "playback.h"
+#include "pod.h"
+#include "revision.h"
+#include "toneport.h"
+#include "usbdefs.h"
+#include "variax.h"
+
+
+#define DRIVER_AUTHOR  "Markus Grabner <grabner@icg.tugraz.at>"
+#define DRIVER_DESC    "Line6 USB Driver"
+#define DRIVER_VERSION "0.8.0"
+
+
+/* table of devices that work with this driver */
+static struct usb_device_id line6_id_table[] = {
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_BASSPODXT) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_BASSPODXTLIVE) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_BASSPODXTPRO) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_GUITARPORT) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_POCKETPOD) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_PODX3) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_PODX3LIVE) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_PODXT) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_PODXTLIVE) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_PODXTPRO) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_TONEPORT_GX) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_TONEPORT_UX1) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_TONEPORT_UX2) },
+	{ USB_DEVICE(LINE6_VENDOR_ID, LINE6_DEVID_VARIAX) },
+	{ },
+};
+MODULE_DEVICE_TABLE (usb, line6_id_table);
+
+static struct line6_properties line6_properties_table[] = {
+	{ "BassPODxt",        LINE6_BIT_BASSPODXT,     LINE6_BIT_CONTROL_PCM },
+	{ "BassPODxt Live",   LINE6_BIT_BASSPODXTLIVE, LINE6_BIT_CONTROL_PCM },
+	{ "BassPODxt Pro",    LINE6_BIT_BASSPODXTPRO,  LINE6_BIT_CONTROL_PCM },
+	{ "GuitarPort",       LINE6_BIT_GUITARPORT,    LINE6_BIT_PCM         },
+	{ "Pocket POD",       LINE6_BIT_POCKETPOD,     LINE6_BIT_CONTROL_PCM },
+	{ "POD X3",           LINE6_BIT_PODX3,         LINE6_BIT_PCM         },
+	{ "POD X3 Live",      LINE6_BIT_PODX3LIVE,     LINE6_BIT_PCM         },
+	{ "PODxt",            LINE6_BIT_PODXT,         LINE6_BIT_CONTROL_PCM },
+	{ "PODxt Live",       LINE6_BIT_PODXTLIVE,     LINE6_BIT_CONTROL_PCM },
+	{ "PODxt Pro",        LINE6_BIT_PODXTPRO,      LINE6_BIT_CONTROL_PCM },
+	{ "TonePort GX",      LINE6_BIT_TONEPORT_GX,   LINE6_BIT_PCM         },
+	{ "TonePort UX1",     LINE6_BIT_TONEPORT_UX1,  LINE6_BIT_PCM         },
+	{ "TonePort UX2",     LINE6_BIT_TONEPORT_UX2,  LINE6_BIT_PCM         },
+	{ "Variax Workbench", LINE6_BIT_VARIAX,        LINE6_BIT_CONTROL     }
+};
+
+
+/*
+	This is Line6's MIDI manufacturer ID.
+*/
+const unsigned char line6_midi_id[] = { 0x00, 0x01, 0x0c };
+
+struct usb_line6 *line6_devices[LINE6_MAX_DEVICES];
+struct workqueue_struct *line6_workqueue;
+
+
+/**
+	 Class for asynchronous messages.
+*/
+struct message
+{
+	struct usb_line6 *line6;
+	const char *buffer;
+	int size;
+	int done;
+};
+
+
+/*
+	Forward declarations.
+*/
+static void line6_data_received(struct urb *urb PT_REGS);
+static int line6_send_raw_message_async_part(struct message *msg, struct urb *urb);
+
+
+/*
+	Start to listen on endpoint.
+*/
+static int line6_start_listen(struct usb_line6 *line6)
+{
+	usb_fill_int_urb(line6->urb_listen,
+									 line6->usbdev,
+									 usb_rcvintpipe(line6->usbdev, line6->ep_control_read),
+									 line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
+									 line6_data_received,
+									 line6,
+									 line6->interval);
+	line6->urb_listen->actual_length = 0;
+	return usb_submit_urb(line6->urb_listen, GFP_KERNEL);
+}
+
+#if DO_DUMP_ANY
+/*
+	Write hexdump to syslog.
+*/
+void line6_write_hexdump(struct usb_line6 *line6, char dir, const unsigned char *buffer, int size)
+{
+	static const int BYTES_PER_LINE = 8;
+	char hexdump[100];
+	char asc[BYTES_PER_LINE + 1];
+	int i, j;
+
+	for(i = 0; i < size; i += BYTES_PER_LINE) {
+		int hexdumpsize = sizeof(hexdump);
+		char *p = hexdump;
+		int n = min(size - i, BYTES_PER_LINE);
+		asc[n] = 0;
+
+		for(j = 0; j < BYTES_PER_LINE; ++j) {
+			int bytes;
+
+			if(j < n) {
+				unsigned char val = buffer[i + j];
+				bytes = snprintf(p, hexdumpsize, " %02X", val);
+				asc[j] = ((val >= 0x20) && (val < 0x7f)) ? val : '.';
+			}
+			else
+				bytes = snprintf(p, hexdumpsize, "   ");
+
+			if(bytes > hexdumpsize)
+				break;  /* buffer overflow */
+
+			p += bytes;
+			hexdumpsize -= bytes;
+		}
+
+		dev_info(line6->ifcdev, "%c%04X:%s %s\n", dir, i, hexdump, asc);
+	}
+}
+#endif
+
+#if DO_DUMP_URB_RECEIVE
+/*
+	Dump URB data to syslog.
+*/
+static void line6_dump_urb(struct urb *urb)
+{
+	struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
+
+	if(urb->status < 0)
+		return;
+
+	line6_write_hexdump(line6, 'R', (unsigned char *)urb->transfer_buffer, urb->actual_length);
+}
+#endif
+
+/*
+	Send raw message in pieces of wMaxPacketSize bytes.
+*/
+int line6_send_raw_message(struct usb_line6 *line6, const char *buffer, int size)
+{
+	int i, done = 0;
+
+#if DO_DUMP_URB_SEND
+	line6_write_hexdump(line6, 'S', buffer, size);
+#endif
+
+	for(i = 0; i < size; i += line6->max_packet_size)	{
+		int partial;
+		const char *frag_buf = buffer + i;
+		int frag_size = min(line6->max_packet_size, size - i);
+		int retval = usb_interrupt_msg(line6->usbdev,
+																	 usb_sndintpipe(line6->usbdev, line6->ep_control_write),
+																	 (char *)frag_buf, frag_size, &partial, LINE6_TIMEOUT * HZ);
+
+		if(retval) {
+			dev_err(line6->ifcdev, "usb_interrupt_msg failed (%d)\n", retval);
+			break;
+		}
+
+		done += frag_size;
+	}
+
+	return done;
+}
+
+/*
+	Notification of completion of asynchronous request transmission.
+*/
+static void line6_async_request_sent(struct urb *urb PT_REGS)
+{
+	struct message *msg = (struct message *)urb->context;
+
+	if(msg->done >= msg->size) {
+		usb_free_urb(urb);
+		kfree(msg);
+	}
+	else
+		line6_send_raw_message_async_part(msg, urb);
+}
+
+/*
+	Asynchronously send part of a raw message.
+*/
+static int line6_send_raw_message_async_part(struct message *msg, struct urb *urb)
+{
+	int retval;
+	struct usb_line6 *line6 = msg->line6;
+	int done = msg->done;
+	int bytes = min(msg->size - done, line6->max_packet_size);
+
+	usb_fill_int_urb(urb,
+									 line6->usbdev,
+									 usb_sndintpipe(line6->usbdev, line6->ep_control_write),
+									 (char *)msg->buffer + done, bytes,
+									 line6_async_request_sent, msg, line6->interval);
+
+#if DO_DUMP_URB_SEND
+	line6_write_hexdump(line6, 'S', (char *)msg->buffer + done, bytes);
+#endif
+
+	msg->done += bytes;
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+
+	if(retval < 0) {
+		dev_err(line6->ifcdev, "line6_send_raw_message_async: usb_submit_urb failed (%d)\n", retval);
+		usb_free_urb(urb);
+		kfree(msg);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+	Asynchronously send raw message.
+*/
+int line6_send_raw_message_async(struct usb_line6 *line6, const char *buffer, int size)
+{
+	struct message *msg;
+	struct urb *urb;
+
+	/* create message: */
+	msg = kmalloc(sizeof(struct message), GFP_ATOMIC);
+
+	if(msg == NULL) {
+		dev_err(line6->ifcdev, "Out of memory\n");
+		return -ENOMEM;
+	}
+
+	/* create URB: */
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+
+	if(urb == NULL) {
+		kfree(msg);
+		dev_err(line6->ifcdev, "Out of memory\n");
+		return -ENOMEM;
+	}
+
+	/* set message data: */
+	msg->line6 = line6;
+	msg->buffer = buffer;
+	msg->size = size;
+	msg->done = 0;
+
+	/* start sending: */
+	return line6_send_raw_message_async_part(msg, urb);
+}
+
+/*
+	Send sysex message in pieces of wMaxPacketSize bytes.
+*/
+int line6_send_sysex_message(struct usb_line6 *line6, const char *buffer, int size)
+{
+	return line6_send_raw_message(line6, buffer, size + SYSEX_EXTRA_SIZE) - SYSEX_EXTRA_SIZE;
+}
+
+/*
+	Allocate buffer for sysex message and prepare header.
+	@param code sysex message code
+	@param size number of bytes between code and sysex end
+*/
+char *line6_alloc_sysex_buffer(struct usb_line6 *line6, int code1, int code2, int size)
+{
+	char *buffer = kmalloc(size + SYSEX_EXTRA_SIZE, GFP_KERNEL);
+
+	if(!buffer) {
+		dev_err(line6->ifcdev, "out of memory\n");
+		return 0;
+	}
+
+	buffer[0] = LINE6_SYSEX_BEGIN;
+	memcpy(buffer + 1, line6_midi_id, sizeof(line6_midi_id));
+	buffer[sizeof(line6_midi_id) + 1] = code1;
+	buffer[sizeof(line6_midi_id) + 2] = code2;
+	buffer[sizeof(line6_midi_id) + 3 + size] = LINE6_SYSEX_END;
+	return buffer;
+}
+
+/*
+	Notification of data received from the Line6 device.
+*/
+static void line6_data_received(struct urb *urb PT_REGS)
+{
+	struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
+	struct MidiBuffer *mb = &line6->line6midi->midibuf_in;
+	int done;
+
+	if(urb->status == -ESHUTDOWN)
+		return;
+
+#if DO_DUMP_URB_RECEIVE
+	line6_dump_urb(urb);
+#endif
+
+	done = midibuf_write(mb, urb->transfer_buffer, urb->actual_length);
+
+	if(done < urb->actual_length) {
+		midibuf_ignore(mb, done);
+		DEBUG_MESSAGES(dev_err(line6->ifcdev, "%d %d buffer overflow - message skipped\n", done, urb->actual_length));
+	}
+
+	for(;;) {
+		done = midibuf_read(mb, line6->buffer_message, LINE6_MESSAGE_MAXLEN);
+
+		if(done == 0)
+			break;
+
+		/* MIDI input filter */
+		if(midibuf_skip_message(mb, line6->line6midi->midi_mask_receive))
+			continue;
+
+		line6->message_length = done;
+#if DO_DUMP_MIDI_RECEIVE
+		line6_write_hexdump(line6, 'r', line6->buffer_message, done);
+#endif
+		line6_midi_receive(line6, line6->buffer_message, done);
+
+		switch(line6->usbdev->descriptor.idProduct) {
+		case LINE6_DEVID_BASSPODXT:
+		case LINE6_DEVID_BASSPODXTLIVE:
+		case LINE6_DEVID_BASSPODXTPRO:
+		case LINE6_DEVID_PODXT:
+		case LINE6_DEVID_PODXTPRO:
+		case LINE6_DEVID_POCKETPOD:
+			pod_process_message((struct usb_line6_pod *)line6);
+			break;
+
+		case LINE6_DEVID_PODXTLIVE:
+			switch(line6->interface_number) {
+			case PODXTLIVE_INTERFACE_POD:
+				pod_process_message((struct usb_line6_pod *)line6);
+				break;
+
+			case PODXTLIVE_INTERFACE_VARIAX:
+				variax_process_message((struct usb_line6_variax *)line6);
+				break;
+
+			default:
+				dev_err(line6->ifcdev, "PODxt Live interface %d not supported\n", line6->interface_number);
+			}
+			break;
+
+		case LINE6_DEVID_VARIAX:
+			variax_process_message((struct usb_line6_variax *)line6);
+			break;
+
+		default:
+			MISSING_CASE;
+		}
+	}
+
+	line6_start_listen(line6);
+}
+
+/*
+	Send channel number (i.e., switch to a different sound).
+*/
+int line6_send_program(struct usb_line6 *line6, int value)
+{
+	int retval;
+	unsigned char *buffer;
+	unsigned int partial;
+
+	buffer = kmalloc(2, GFP_KERNEL);
+
+	if(!buffer) {
+		dev_err(line6->ifcdev, "out of memory\n");
+		return -ENOMEM;
+	}
+
+	buffer[0] = LINE6_PROGRAM_CHANGE | LINE6_CHANNEL_HOST;
+	buffer[1] = value;
+
+#if DO_DUMP_URB_SEND
+	line6_write_hexdump(line6, 'S', buffer, 2);
+#endif
+
+	retval = usb_interrupt_msg(line6->usbdev,
+														 usb_sndintpipe(line6->usbdev, line6->ep_control_write),
+														 buffer, 2, &partial, LINE6_TIMEOUT * HZ);
+
+	if(retval)
+		dev_err(line6->ifcdev, "usb_interrupt_msg failed (%d)\n", retval);
+
+	kfree(buffer);
+	return retval;
+}
+
+/*
+	Transmit Line6 control parameter.
+*/
+int line6_transmit_parameter(struct usb_line6 *line6, int param, int value)
+{
+	int retval;
+	unsigned char *buffer;
+	unsigned int partial;
+
+	buffer = kmalloc(3, GFP_KERNEL);
+
+	if(!buffer) {
+		dev_err(line6->ifcdev, "out of memory\n");
+		return -ENOMEM;
+	}
+
+	buffer[0] = LINE6_PARAM_CHANGE | LINE6_CHANNEL_HOST;
+	buffer[1] = param;
+	buffer[2] = value;
+
+#if DO_DUMP_URB_SEND
+	line6_write_hexdump(line6, 'S', buffer, 3);
+#endif
+
+	retval = usb_interrupt_msg(line6->usbdev,
+														 usb_sndintpipe(line6->usbdev, line6->ep_control_write),
+														 buffer, 3, &partial, LINE6_TIMEOUT * HZ);
+
+	if(retval)
+		dev_err(line6->ifcdev, "usb_interrupt_msg failed (%d)\n", retval);
+
+	kfree(buffer);
+	return retval;
+}
+
+/*
+	Read data from device.
+*/
+int line6_read_data(struct usb_line6 *line6, int address, void *data, size_t datalen)
+{
+	struct usb_device *usbdev = line6->usbdev;
+	int ret;
+	unsigned char len;
+
+	/* query the serial number: */
+	ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67,
+												USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+												(datalen << 8) | 0x21, address, 0, 0, LINE6_TIMEOUT * HZ);
+
+	if(ret < 0) {
+		dev_err(line6->ifcdev, "read request failed (error %d)\n", ret);
+		return ret;
+	}
+
+	/* Wait for data length. We'll get a couple of 0xff until length arrives. */
+	do {
+		ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x67,
+													USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
+													0x0012, 0x0000,	&len, 1, LINE6_TIMEOUT * HZ);
+		if(ret < 0) {
+			dev_err(line6->ifcdev, "receive length failed (error %d)\n", ret);
+			return ret;
+		}
+	}
+	while(len == 0xff);
+
+	if(len != datalen) {  /* should be equal or something went wrong */
+		dev_err(line6->ifcdev, "length mismatch (expected %d, got %d)\n", (int)datalen, (int)len);
+		return -EINVAL;
+	}
+
+	/* receive the result: */
+	ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x67,
+												USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
+												0x0013, 0x0000, data, datalen, LINE6_TIMEOUT * HZ);
+
+	if(ret < 0) {
+		dev_err(line6->ifcdev, "read failed (error %d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/*
+	Write data to device.
+*/
+int line6_write_data(struct usb_line6 *line6, int address, void *data, size_t datalen)
+{
+	struct usb_device *usbdev = line6->usbdev;
+	int ret;
+	unsigned char status;
+
+	ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev,0), 0x67,
+									USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+									0x0022, address, data, datalen, LINE6_TIMEOUT * HZ);
+
+	if(ret < 0) {
+		dev_err(line6->ifcdev, "write request failed (error %d)\n", ret);
+		return ret;
+	}
+
+	do {
+		ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev,0), 0x67,
+										USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
+										0x0012, 0x0000,	&status, 1, LINE6_TIMEOUT * HZ);
+
+		if(ret < 0) {
+			dev_err(line6->ifcdev, "receiving status failed (error %d)\n", ret);
+			return ret;
+		}
+	}
+	while(status == 0xff);
+
+	if(status != 0) {
+		dev_err(line6->ifcdev, "write failed (error %d)\n", ret);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+	Read Line6 device serial number.
+	(POD, TonePort, GuitarPort)
+*/
+int line6_read_serial_number(struct usb_line6 *line6, int *serial_number)
+{
+	return line6_read_data(line6, 0x80d0, serial_number, sizeof(*serial_number));
+}
+
+/*
+	No operation (i.e., unsupported).
+*/
+ssize_t line6_nop_read(struct device *dev, DEVICE_ATTRIBUTE char *buf)
+{
+	return 0;
+}
+
+/*
+	No operation (i.e., unsupported).
+*/
+ssize_t line6_nop_write(struct device *dev, DEVICE_ATTRIBUTE const char *buf, size_t count)
+{
+	return count;
+}
+
+/*
+	"write" request on "raw" special file.
+*/
+#if CREATE_RAW_FILE
+ssize_t line6_set_raw(struct device *dev, DEVICE_ATTRIBUTE const char *buf, size_t count)
+{
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6 *line6 = usb_get_intfdata(interface);
+	line6_send_raw_message(line6, buf, count);
+	return count;
+}
+#endif
+
+/*
+	Generic destructor.
+*/
+static void line6_destruct(struct usb_interface *interface)
+{
+	struct usb_line6 *line6;
+	if(interface == NULL) return;
+	line6 = usb_get_intfdata(interface);
+	if(line6 == NULL) return;
+
+	/* free buffer memory first: */
+	if(line6->buffer_message != NULL) kfree(line6->buffer_message);
+	if(line6->buffer_listen != NULL) kfree(line6->buffer_listen);
+
+	/* then free URBs: */
+	if(line6->urb_listen != NULL) usb_free_urb(line6->urb_listen);
+
+	/* make sure the device isn't destructed twice: */
+	usb_set_intfdata(interface, NULL);
+
+	/* free interface data: */
+	kfree(line6);
+}
+
+static void line6_list_devices(void)
+{
+	int i;
+
+	for(i = 0; i < LINE6_MAX_DEVICES; ++i) {
+		struct usb_line6 *dev = line6_devices[i];
+		printk(KERN_INFO "Line6 device %d: ", i);
+
+		if(dev == NULL)
+			printk("(not used)\n");
+		else
+			printk("%s:%d\n", dev->properties->name, dev->interface_number);
+	}
+}
+
+/*
+	Probe USB device.
+*/
+static int line6_probe(struct usb_interface *interface, const struct usb_device_id *id)
+{
+	int devtype;
+	struct usb_device *usbdev = 0;
+	struct usb_line6 *line6 = 0;
+	const struct line6_properties *properties;
+	int devnum;
+	int interface_number, alternate = 0;
+	int product;
+	int size = 0;
+	int ep_read = 0, ep_write = 0;
+	int ret;
+
+	if(interface == NULL) return -ENODEV;
+	usbdev = interface_to_usbdev(interface);
+	if(usbdev == NULL) return -ENODEV;
+
+	/* increment reference counters: */
+	usb_get_intf(interface);
+	usb_get_dev(usbdev);
+
+	/* we don't handle multiple configurations */
+	if(usbdev->descriptor.bNumConfigurations != 1)
+		return -ENODEV;
+
+	/* check vendor and product id */
+	for(devtype = sizeof(line6_id_table) / sizeof(line6_id_table[0]) - 1; devtype--;)
+		if((le16_to_cpu(usbdev->descriptor.idVendor) == line6_id_table[devtype].idVendor) &&
+			 (le16_to_cpu(usbdev->descriptor.idProduct) == line6_id_table[devtype].idProduct))
+			break;
+
+	if(devtype < 0)
+		return -ENODEV;
+
+	/* find free slot in device table: */
+	for(devnum = 0; devnum < LINE6_MAX_DEVICES; ++devnum)
+		if(line6_devices[devnum] == NULL)
+			break;
+
+	if(devnum == LINE6_MAX_DEVICES)
+		return -ENODEV;
+
+	/* initialize device info: */
+	properties = &line6_properties_table[devtype];
+	dev_info(&interface->dev, "Line6 %s found\n", properties->name);
+	product = le16_to_cpu(usbdev->descriptor.idProduct);
+
+	/* query interface number */
+	interface_number = interface->cur_altsetting->desc.bInterfaceNumber;
+
+	switch(product) {
+	case LINE6_DEVID_BASSPODXTLIVE:
+	case LINE6_DEVID_POCKETPOD:
+	case LINE6_DEVID_PODXTLIVE:
+	case LINE6_DEVID_VARIAX:
+		alternate = 1;
+		break;
+
+	case LINE6_DEVID_PODX3:
+	case LINE6_DEVID_PODX3LIVE:
+		switch(interface_number) {
+		case 0: alternate = 1; break;
+		case 1: alternate = 0; break;
+		default: MISSING_CASE;
+		}
+		break;
+
+	case LINE6_DEVID_BASSPODXT:
+	case LINE6_DEVID_BASSPODXTPRO:
+	case LINE6_DEVID_PODXT:
+	case LINE6_DEVID_PODXTPRO:
+		alternate = 5;
+		break;
+
+	case LINE6_DEVID_TONEPORT_GX:
+	case LINE6_DEVID_GUITARPORT:
+		alternate = 2;  // 1..4 seem to be ok
+		break;
+
+	case LINE6_DEVID_TONEPORT_UX1:
+	case LINE6_DEVID_TONEPORT_UX2:
+		switch(interface_number) {
+		case 0: alternate = 2; break; /* defaults to 44.1kHz, 16-bit */
+		case 1: alternate = 0; break;
+		default: MISSING_CASE;
+		}
+		break;
+
+	default:
+		MISSING_CASE;
+		return -ENODEV;
+	}
+
+	if((ret = usb_set_interface(usbdev, interface_number, alternate)) < 0) {
+		dev_err(&interface->dev, "set_interface failed\n");
+		return ret;
+	}
+
+	/* initialize device data based on product id: */
+	switch(product) {
+	case LINE6_DEVID_BASSPODXT:
+	case LINE6_DEVID_BASSPODXTLIVE:
+	case LINE6_DEVID_BASSPODXTPRO:
+	case LINE6_DEVID_POCKETPOD:
+	case LINE6_DEVID_PODXT:
+	case LINE6_DEVID_PODXTPRO:
+		size = sizeof(struct usb_line6_pod);
+		ep_read  = 0x84;
+		ep_write = 0x03;
+		break;
+
+	case LINE6_DEVID_PODX3:
+	case LINE6_DEVID_PODX3LIVE:
+		/* currently unused! */
+		size = sizeof(struct usb_line6_pod);
+		ep_read  = 0x81;
+		ep_write = 0x01;
+		break;
+
+	case LINE6_DEVID_TONEPORT_GX:
+	case LINE6_DEVID_TONEPORT_UX1:
+	case LINE6_DEVID_TONEPORT_UX2:
+	case LINE6_DEVID_GUITARPORT:
+		size = sizeof(struct usb_line6_toneport);
+		/* these don't have a control channel */
+		break;
+
+	case LINE6_DEVID_PODXTLIVE:
+		switch(interface_number) {
+		case PODXTLIVE_INTERFACE_POD:
+			size = sizeof(struct usb_line6_pod);
+			ep_read  = 0x84;
+			ep_write = 0x03;
+			break;
+
+		case PODXTLIVE_INTERFACE_VARIAX:
+			size = sizeof(struct usb_line6_variax);
+			ep_read  = 0x86;
+			ep_write = 0x05;
+			break;
+
+		default:
+			return -ENODEV;
+		}
+		break;
+
+	case LINE6_DEVID_VARIAX:
+		size = sizeof(struct usb_line6_variax);
+		ep_read  = 0x82;
+		ep_write = 0x01;
+		break;
+
+	default:
+		MISSING_CASE;
+		return -ENODEV;
+	}
+
+	if(size == 0) {
+		dev_err(line6->ifcdev, "driver bug: interface data size not set\n");
+		return -ENODEV;
+	}
+
+	line6 = kzalloc(size, GFP_KERNEL);
+
+	if(line6 == NULL) {
+		dev_err(&interface->dev, "Out of memory\n");
+		return -ENOMEM;
+	}
+
+	/* store basic data: */
+	line6->interface_number = interface_number;
+	line6->properties = properties;
+	line6->usbdev = usbdev;
+	line6->ifcdev = &interface->dev;
+	line6->ep_control_read = ep_read;
+	line6->ep_control_write = ep_write;
+	line6->product = product;
+
+	/* get data from endpoint descriptor (see usb_maxpacket): */
+	{
+		struct usb_host_endpoint *ep;
+		unsigned epnum = usb_pipeendpoint(usb_rcvintpipe(usbdev, ep_read));
+		ep = usbdev->ep_in[epnum];
+
+		if(ep != NULL) {
+			line6->interval = ep->desc.bInterval;
+			line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);
+		}
+		else {
+			line6->interval = LINE6_FALLBACK_INTERVAL;
+			line6->max_packet_size = LINE6_FALLBACK_MAXPACKETSIZE;
+			dev_err(line6->ifcdev, "endpoint not available, using fallback values");
+		}
+	}
+
+	usb_set_intfdata(interface, line6);
+
+	if(properties->capabilities & LINE6_BIT_CONTROL) {
+		/* initialize USB buffers: */
+		line6->buffer_listen = kmalloc(LINE6_BUFSIZE_LISTEN, GFP_KERNEL);
+
+		if(line6->buffer_listen == NULL) {
+			dev_err(&interface->dev, "Out of memory\n");
+			line6_destruct(interface);
+			return -ENOMEM;
+		}
+
+		line6->buffer_message = kmalloc(LINE6_MESSAGE_MAXLEN, GFP_KERNEL);
+
+		if(line6->buffer_message == NULL) {
+			dev_err(&interface->dev, "Out of memory\n");
+			line6_destruct(interface);
+			return -ENOMEM;
+		}
+
+		line6->urb_listen = usb_alloc_urb(0, GFP_KERNEL);
+
+		if(line6->urb_listen == NULL) {
+			dev_err(&interface->dev, "Out of memory\n");
+			line6_destruct(interface);
+			return -ENOMEM;
+		}
+
+		if((ret = line6_start_listen(line6)) < 0) {
+			dev_err(&interface->dev, " line6_probe: usb_submit_urb failed\n");
+			line6_destruct(interface);
+			return ret;
+		}
+	}
+
+	/* initialize device data based on product id: */
+	switch(product) {
+	case LINE6_DEVID_BASSPODXT:
+	case LINE6_DEVID_BASSPODXTLIVE:
+	case LINE6_DEVID_BASSPODXTPRO:
+	case LINE6_DEVID_POCKETPOD:
+	case LINE6_DEVID_PODX3:
+	case LINE6_DEVID_PODX3LIVE:
+	case LINE6_DEVID_PODXT:
+	case LINE6_DEVID_PODXTPRO:
+		ret = pod_init(interface, (struct usb_line6_pod *)line6);
+		break;
+
+	case LINE6_DEVID_PODXTLIVE:
+		switch(interface_number) {
+		case PODXTLIVE_INTERFACE_POD:
+			ret = pod_init(interface, (struct usb_line6_pod *)line6);
+			break;
+
+		case PODXTLIVE_INTERFACE_VARIAX:
+			ret = variax_init(interface, (struct usb_line6_variax *)line6);
+			break;
+
+		default:
+			dev_err(&interface->dev, "PODxt Live interface %d not supported\n", interface_number);
+			ret = -ENODEV;
+		}
+
+		break;
+
+	case LINE6_DEVID_VARIAX:
+		ret = variax_init(interface, (struct usb_line6_variax *)line6);
+		break;
+
+	case LINE6_DEVID_TONEPORT_GX:
+	case LINE6_DEVID_TONEPORT_UX1:
+	case LINE6_DEVID_TONEPORT_UX2:
+	case LINE6_DEVID_GUITARPORT:
+		ret = toneport_init(interface, (struct usb_line6_toneport *)line6);
+		break;
+
+	default:
+		MISSING_CASE;
+		ret = -ENODEV;
+	}
+
+	if(ret < 0) {
+		line6_destruct(interface);
+		return ret;
+	}
+
+	if((ret = sysfs_create_link(&interface->dev.kobj, &usbdev->dev.kobj, "usb_device")) < 0) {
+		line6_destruct(interface);
+		return ret;
+	}
+
+	dev_info(&interface->dev, "Line6 %s now attached\n", line6->properties->name);
+	line6_devices[devnum] = line6;
+	line6_list_devices();
+	return ret;
+}
+
+/*
+	Line6 device disconnected.
+*/
+static void line6_disconnect(struct usb_interface *interface)
+{
+	struct usb_line6 *line6;
+	struct usb_device *usbdev;
+	int interface_number, i;
+
+	if(interface == NULL) return;
+	usbdev = interface_to_usbdev(interface);
+	if(usbdev == NULL) return;
+
+	sysfs_remove_link(&interface->dev.kobj, "usb_device");
+
+	interface_number = interface->cur_altsetting->desc.bInterfaceNumber;
+	line6 = usb_get_intfdata(interface);
+
+	if(line6 != NULL) {
+		if(line6->urb_listen != NULL) usb_kill_urb(line6->urb_listen);
+
+		if(usbdev != line6->usbdev)
+			dev_err(line6->ifcdev, "driver bug: inconsistent usb device\n");
+
+		switch(line6->usbdev->descriptor.idProduct) {
+		case LINE6_DEVID_BASSPODXT:
+		case LINE6_DEVID_BASSPODXTLIVE:
+		case LINE6_DEVID_BASSPODXTPRO:
+		case LINE6_DEVID_POCKETPOD:
+		case LINE6_DEVID_PODX3:
+		case LINE6_DEVID_PODX3LIVE:
+		case LINE6_DEVID_PODXT:
+		case LINE6_DEVID_PODXTPRO:
+			pod_disconnect(interface);
+			break;
+
+		case LINE6_DEVID_PODXTLIVE:
+			switch(interface_number) {
+			case PODXTLIVE_INTERFACE_POD:
+				pod_disconnect(interface);
+				break;
+
+			case PODXTLIVE_INTERFACE_VARIAX:
+				variax_disconnect(interface);
+				break;
+			}
+
+			break;
+
+		case LINE6_DEVID_VARIAX:
+			variax_disconnect(interface);
+			break;
+
+		case LINE6_DEVID_TONEPORT_GX:
+		case LINE6_DEVID_TONEPORT_UX1:
+		case LINE6_DEVID_TONEPORT_UX2:
+		case LINE6_DEVID_GUITARPORT:
+			toneport_disconnect(interface);
+			break;
+
+		default:
+			MISSING_CASE;
+		}
+
+		dev_info(&interface->dev, "Line6 %s now disconnected\n", line6->properties->name);
+
+		for(i = LINE6_MAX_DEVICES; i--;)
+			if(line6_devices[i] == line6)
+				line6_devices[i] = 0;
+	}
+
+	line6_destruct(interface);
+
+	/* decrement reference counters: */
+	usb_put_intf(interface);
+	usb_put_dev(usbdev);
+
+	line6_list_devices();
+}
+
+static struct usb_driver line6_driver = {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 16)
+	.owner = THIS_MODULE,
+#endif
+	.name = DRIVER_NAME,
+	.probe = line6_probe,
+	.disconnect = line6_disconnect,
+	.id_table = line6_id_table,
+};
+
+/*
+	Module initialization.
+*/
+static int __init line6_init(void)
+{
+	int i, retval;
+
+	printk("%s driver version %s%s\n", DRIVER_NAME, DRIVER_VERSION, DRIVER_REVISION);
+	line6_workqueue = create_workqueue(DRIVER_NAME);
+
+	if(line6_workqueue == 0) {
+		err("couldn't create workqueue");
+		return -EINVAL;
+	}
+
+	for(i = LINE6_MAX_DEVICES; i--;)
+		line6_devices[i] = 0;
+
+	retval = usb_register(&line6_driver);
+
+	if(retval)
+		err("usb_register failed. Error number %d", retval);
+
+	return retval;
+}
+
+/*
+	Module cleanup.
+*/
+static void __exit line6_exit(void)
+{
+	destroy_workqueue(line6_workqueue);
+	usb_deregister(&line6_driver);
+}
+
+module_init(line6_init);
+module_exit(line6_exit);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);