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>

29 files changed, 6962 insertions, 0 deletions

diff --git a/drivers/staging/line6/Kconfig b/drivers/staging/line6/Kconfig
new file mode 100644
index 00000000000..3c1ffcb8cb1
--- /dev/null
+++ b/drivers/staging/line6/Kconfig
@@ -0,0 +1,20 @@
+config LINE6_USB
+	tristate "Line6 USB support"
+	depends on USB
+	help
+	  This is a 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)
+
+	  Preliminary support for the Variax Workbench is included.
+
diff --git a/drivers/staging/line6/Makefile b/drivers/staging/line6/Makefile
new file mode 100644
index 00000000000..a1c93edc6b1
--- /dev/null
+++ b/drivers/staging/line6/Makefile
@@ -0,0 +1,15 @@
+obj-$(CONFIG_LINE6_USB)		+= line6usb.o
+
+line6usb-objs := 		\
+		audio.o		\
+		capture.o	\
+		control.o	\
+		driver.o	\
+		dumprequest.o	\
+		midi.o		\
+		midibuf.o	\
+		pcm.o		\
+		playback.o	\
+		pod.o		\
+		toneport.o	\
+		variax.o
diff --git a/drivers/staging/line6/audio.c b/drivers/staging/line6/audio.c
new file mode 100644
index 00000000000..e15fa1f6ee4
--- /dev/null
+++ b/drivers/staging/line6/audio.c
@@ -0,0 +1,69 @@
+/*
+ * 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 <sound/core.h>
+#include <sound/initval.h>
+
+
+static int line6_index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+static char *line6_id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
+
+
+/*
+	Initialize the Line6 USB audio system.
+*/
+int line6_init_audio(struct usb_line6 *line6)
+{
+	static int dev = 0;
+	struct snd_card *card;
+
+	card = snd_card_new(line6_index[dev], line6_id[dev], THIS_MODULE, 0);
+
+	if(card == NULL)
+		return -ENOMEM;
+
+	line6->card = card;
+
+	strcpy(card->driver, DRIVER_NAME);
+	strcpy(card->shortname, "Line6-USB");
+	sprintf(card->longname, "Line6 %s at USB %s", line6->properties->name, line6->ifcdev->bus_id);  /* 80 chars - see asound.h */
+	return 0;
+}
+
+/*
+	Register the Line6 USB audio system.
+*/
+int line6_register_audio(struct usb_line6 *line6)
+{
+	int err;
+
+	if((err = snd_card_register(line6->card)) < 0)
+		return err;
+
+	return 0;
+}
+
+/*
+	Cleanup the Line6 USB audio system.
+*/
+void line6_cleanup_audio(struct usb_line6 *line6)
+{
+	struct snd_card *card = line6->card;
+
+	if(card == 0)
+		return;
+
+	snd_card_disconnect(card);
+	snd_card_free(card);
+	line6->card = 0;
+}
diff --git a/drivers/staging/line6/audio.h b/drivers/staging/line6/audio.h
new file mode 100644
index 00000000000..cc0245adbcd
--- /dev/null
+++ b/drivers/staging/line6/audio.h
@@ -0,0 +1,24 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef AUDIO_H
+#define AUDIO_H
+
+
+#include "driver.h"
+
+
+extern void line6_cleanup_audio(struct usb_line6 *);
+extern int line6_init_audio(struct usb_line6 *);
+extern int line6_register_audio(struct usb_line6 *);
+
+
+#endif
diff --git a/drivers/staging/line6/capture.c b/drivers/staging/line6/capture.c
new file mode 100644
index 00000000000..5dec3bfff04
--- /dev/null
+++ b/drivers/staging/line6/capture.c
@@ -0,0 +1,370 @@
+/*
+ * 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 <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include "audio.h"
+#include "pcm.h"
+#include "pod.h"
+
+
+/*
+	Find a free URB and submit it.
+*/
+static int submit_audio_in_urb(struct snd_pcm_substream *substream)
+{
+	int index;
+	unsigned long flags;
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+	int i, urb_size;
+	struct urb *urb_in;
+
+	spin_lock_irqsave(&line6pcm->lock_audio_in, flags);
+	index = find_first_zero_bit(&line6pcm->active_urb_in, LINE6_ISO_BUFFERS);
+
+	if(index < 0 || index >= LINE6_ISO_BUFFERS) {
+		spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
+		dev_err(s2m(substream), "no free URB found\n");
+		return -EINVAL;
+	}
+
+	urb_in = line6pcm->urb_audio_in[index];
+	urb_size = 0;
+
+	for(i = 0; i < LINE6_ISO_PACKETS; ++i) {
+		struct usb_iso_packet_descriptor *fin = &urb_in->iso_frame_desc[i];
+		fin->offset = urb_size;
+		fin->length = line6pcm->max_packet_size;
+		urb_size += line6pcm->max_packet_size;
+	}
+
+	urb_in->transfer_buffer = line6pcm->buffer_in + index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
+	urb_in->transfer_buffer_length = urb_size;
+	urb_in->context = substream;
+
+	if(usb_submit_urb(urb_in, GFP_ATOMIC) == 0)
+		set_bit(index, &line6pcm->active_urb_in);
+	else
+		dev_err(s2m(substream), "URB in #%d submission failed\n", index);
+
+	spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
+	return 0;
+}
+
+/*
+	Submit all currently available capture URBs.
+*/
+static int submit_audio_in_all_urbs(struct snd_pcm_substream *substream)
+{
+	int ret, i;
+
+	for(i = 0; i < LINE6_ISO_BUFFERS; ++i)
+		if((ret = submit_audio_in_urb(substream)) < 0)
+			return ret;
+
+	return 0;
+}
+
+/*
+	Unlink all currently active capture URBs.
+*/
+static void unlink_audio_in_urbs(struct snd_line6_pcm *line6pcm)
+{
+	unsigned int i;
+
+	for(i = LINE6_ISO_BUFFERS; i--;) {
+		if(test_bit(i, &line6pcm->active_urb_in)) {
+			if(!test_and_set_bit(i, &line6pcm->unlink_urb_in)) {
+				struct urb *u = line6pcm->urb_audio_in[i];
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 14)
+				u->transfer_flags |= URB_ASYNC_UNLINK;
+#endif
+				usb_unlink_urb(u);
+			}
+		}
+	}
+}
+
+/*
+	Wait until unlinking of all currently active capture URBs has been finished.
+*/
+static void wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
+{
+	int timeout = HZ;
+	unsigned int i;
+	int alive;
+
+	do {
+		alive = 0;
+		for (i = LINE6_ISO_BUFFERS; i--;) {
+			if (test_bit(i, &line6pcm->active_urb_in))
+				alive++;
+		}
+		if (! alive)
+			break;
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(1);
+	} while (--timeout > 0);
+	if (alive)
+		snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
+
+	line6pcm->active_urb_in = 0;
+	line6pcm->unlink_urb_in = 0;
+}
+
+/*
+	Unlink all currently active capture URBs, and wait for finishing.
+*/
+void unlink_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
+{
+	unlink_audio_in_urbs(line6pcm);
+	wait_clear_audio_in_urbs(line6pcm);
+}
+
+/*
+	Callback for completed capture URB.
+*/
+static void audio_in_callback(struct urb *urb PT_REGS)
+{
+	int i, index, length = 0, shutdown = 0;
+	int frames;
+	unsigned long flags;
+
+	struct snd_pcm_substream *substream = (struct snd_pcm_substream *)urb->context;
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+	const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	/* find index of URB */
+	for(index = 0; index < LINE6_ISO_BUFFERS; ++index)
+		if(urb == line6pcm->urb_audio_in[index])
+			break;
+
+#if DO_DUMP_PCM_RECEIVE
+	for(i = 0; i < LINE6_ISO_PACKETS; ++i) {
+		struct usb_iso_packet_descriptor *fout = &urb->iso_frame_desc[i];
+		line6_write_hexdump(line6pcm->line6, 'C', urb->transfer_buffer + fout->offset, fout->length);
+	}
+#endif
+
+	spin_lock_irqsave(&line6pcm->lock_audio_in, flags);
+
+	for(i = 0; i < LINE6_ISO_PACKETS; ++i) {
+		char *fbuf;
+		int fsize;
+		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
+
+		if(fin->status == -18) {
+			shutdown = 1;
+			break;
+		}
+
+		fbuf = urb->transfer_buffer + fin->offset;
+		fsize = fin->actual_length;
+		length += fsize;
+
+		if(fsize > 0) {
+			frames = fsize / bytes_per_frame;
+
+			if(line6pcm->pos_in_done + frames > runtime->buffer_size) {
+				/*
+					The transferred area goes over buffer boundary,
+					copy two separate chunks.
+				*/
+				int len;
+				len = runtime->buffer_size - line6pcm->pos_in_done;
+
+				if(len > 0) {
+					memcpy(runtime->dma_area + line6pcm->pos_in_done * bytes_per_frame, fbuf, len * bytes_per_frame);
+					memcpy(runtime->dma_area, fbuf + len * bytes_per_frame, (frames - len) * bytes_per_frame);
+				}
+				else
+					dev_err(s2m(substream), "driver bug: len = %d\n", len);  /* this is somewhat paranoid */
+			}
+			else {
+				/* copy single chunk */
+				memcpy(runtime->dma_area + line6pcm->pos_in_done * bytes_per_frame, fbuf, fsize * bytes_per_frame);
+			}
+
+			if((line6pcm->pos_in_done += frames) >= runtime->buffer_size)
+				line6pcm->pos_in_done -= runtime->buffer_size;
+		}
+	}
+
+	clear_bit(index, &line6pcm->active_urb_in);
+
+	if(test_bit(index, &line6pcm->unlink_urb_in))
+		shutdown = 1;
+
+	spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
+
+	if(!shutdown) {
+		submit_audio_in_urb(substream);
+
+		if((line6pcm->bytes_in += length) >= line6pcm->period_in) {
+			line6pcm->bytes_in -= line6pcm->period_in;
+			snd_pcm_period_elapsed(substream);
+		}
+	}
+}
+
+/* open capture callback */
+static int snd_line6_capture_open(struct snd_pcm_substream *substream)
+{
+	int err;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+
+	if((err = snd_pcm_hw_constraint_ratdens(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+																					(&line6pcm->properties->snd_line6_rates))) < 0)
+		return err;
+
+	runtime->hw = line6pcm->properties->snd_line6_capture_hw;
+	return 0;
+}
+
+/* close capture callback */
+static int snd_line6_capture_close(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+/* hw_params capture callback */
+static int snd_line6_capture_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *hw_params)
+{
+	int ret;
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+
+	/* -- Florian Demski [FD] */
+	/* don't ask me why, but this fixes the bug on my machine */
+	if ( line6pcm == NULL ) {
+		if ( substream->pcm == NULL )
+			return -ENOMEM;
+		if ( substream->pcm->private_data == NULL )
+			return -ENOMEM;
+		substream->private_data = substream->pcm->private_data;
+		line6pcm = snd_pcm_substream_chip( substream );
+	}
+	/* -- [FD] end */
+
+	if((ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params))) < 0)
+		return ret;
+
+	line6pcm->period_in = params_period_bytes(hw_params);
+	line6pcm->buffer_in = kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS * LINE6_ISO_PACKET_SIZE_MAX, GFP_KERNEL);
+
+	if(!line6pcm->buffer_in) {
+		dev_err(s2m(substream), "cannot malloc buffer_in\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/* hw_free capture callback */
+static int snd_line6_capture_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+	unlink_wait_clear_audio_in_urbs(line6pcm);
+
+	if(line6pcm->buffer_in) {
+		kfree(line6pcm->buffer_in);
+		line6pcm->buffer_in = 0;
+	}
+
+	return snd_pcm_lib_free_pages(substream);
+}
+
+/* trigger callback */
+int snd_line6_capture_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+	int err;
+	line6pcm->count_in = 0;
+
+	switch(cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		if(!test_and_set_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags)) {
+			err = submit_audio_in_all_urbs(substream);
+
+			if(err < 0) {
+				clear_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags);
+				return err;
+			}
+		}
+
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+		if(test_and_clear_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags))
+			unlink_audio_in_urbs(line6pcm);
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* capture pointer callback */
+static snd_pcm_uframes_t
+snd_line6_capture_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
+	return line6pcm->pos_in_done;
+}
+
+/* capture operators */
+struct snd_pcm_ops snd_line6_capture_ops = {
+	.open =        snd_line6_capture_open,
+	.close =       snd_line6_capture_close,
+	.ioctl =       snd_pcm_lib_ioctl,
+	.hw_params =   snd_line6_capture_hw_params,
+	.hw_free =     snd_line6_capture_hw_free,
+	.prepare =     snd_line6_prepare,
+	.trigger =     snd_line6_trigger,
+	.pointer =     snd_line6_capture_pointer,
+};
+
+int create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
+{
+	int i;
+
+	/* create audio URBs and fill in constant values: */
+	for(i = 0; i < LINE6_ISO_BUFFERS; ++i) {
+		struct urb *urb;
+
+		/* URB for audio in: */
+		urb = line6pcm->urb_audio_in[i] = usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
+
+		if(urb == NULL) {
+			dev_err(line6pcm->line6->ifcdev, "Out of memory\n");
+			return -ENOMEM;
+		}
+
+		urb->dev = line6pcm->line6->usbdev;
+		urb->pipe = usb_rcvisocpipe(line6pcm->line6->usbdev, line6pcm->ep_audio_read & USB_ENDPOINT_NUMBER_MASK);
+		urb->transfer_flags = URB_ISO_ASAP;
+		urb->start_frame = -1;
+		urb->number_of_packets = LINE6_ISO_PACKETS;
+		urb->interval = LINE6_ISO_INTERVAL;
+		urb->error_count = 0;
+		urb->complete = audio_in_callback;
+	}
+
+	return 0;
+}
diff --git a/drivers/staging/line6/capture.h b/drivers/staging/line6/capture.h
new file mode 100644
index 00000000000..7b92e4de392
--- /dev/null
+++ b/drivers/staging/line6/capture.h
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef CAPTURE_H
+#define CAPTURE_H
+
+
+#include "driver.h"
+
+#include <sound/pcm.h>
+
+#include "pcm.h"
+
+
+extern struct snd_pcm_ops snd_line6_capture_ops;
+
+
+extern int create_audio_in_urbs(struct snd_line6_pcm *line6pcm);
+extern int snd_line6_capture_trigger(struct snd_pcm_substream *substream, int cmd);
+extern void unlink_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm);
+
+
+#endif
diff --git a/drivers/staging/line6/config.h b/drivers/staging/line6/config.h
new file mode 100644
index 00000000000..d5ed1a740b0
--- /dev/null
+++ b/drivers/staging/line6/config.h
@@ -0,0 +1,73 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
+#include <linux/config.h>
+#endif
+
+#ifdef CONFIG_USB_DEBUG
+#define DEBUG 1
+#endif
+
+
+/**
+   Development tools.
+*/
+#define DO_DEBUG_MESSAGES    0
+#define DO_DUMP_URB_SEND     DO_DEBUG_MESSAGES
+#define DO_DUMP_URB_RECEIVE  DO_DEBUG_MESSAGES
+#define DO_DUMP_PCM_SEND     0
+#define DO_DUMP_PCM_RECEIVE  0
+#define DO_DUMP_MIDI_SEND    DO_DEBUG_MESSAGES
+#define DO_DUMP_MIDI_RECEIVE DO_DEBUG_MESSAGES
+#define DO_DUMP_ANY          (DO_DUMP_URB_SEND || DO_DUMP_URB_RECEIVE || \
+			      DO_DUMP_PCM_SEND || DO_DUMP_PCM_RECEIVE || \
+			      DO_DUMP_MIDI_SEND || DO_DUMP_MIDI_RECEIVE)
+#define CREATE_RAW_FILE      0
+
+#if DO_DEBUG_MESSAGES
+#define CHECKPOINT printk("line6usb: %s (%s:%d)\n", __FUNCTION__, __FILE__, __LINE__)
+#endif
+
+/**
+   In Linux 2.6.13 and later, the device_attribute is passed to the sysfs
+   get/set functions (see /usr/src/linux/include/linux/device.h).
+*/
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 13)
+#define DEVICE_ATTRIBUTE struct device_attribute *attr,
+#else
+#define DEVICE_ATTRIBUTE
+#endif
+
+/**
+   In Linux 2.6.20 and later, the pt_regs is no longer passed to USB callback
+   functions.
+*/
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
+#define PT_REGS
+#else
+#define PT_REGS , struct pt_regs *regs
+#endif
+
+#if DO_DEBUG_MESSAGES
+#define DEBUG_MESSAGES(x) (x)
+#else
+#define DEBUG_MESSAGES(x)
+#endif
+
+
+#endif
diff --git a/drivers/staging/line6/control.c b/drivers/staging/line6/control.c
new file mode 100644
index 00000000000..d44d06d7b13
--- /dev/null
+++ b/drivers/staging/line6/control.c
@@ -0,0 +1,702 @@
+/*
+ * 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/usb.h>
+
+#include "control.h"
+#include "pod.h"
+#include "usbdefs.h"
+#include "variax.h"
+
+#define DEVICE_ATTR2(_name1,_name2,_mode,_show,_store) \
+struct device_attribute dev_attr_##_name1 = __ATTR(_name2,_mode,_show,_store)
+
+#define LINE6_PARAM_R(PREFIX, prefix, type, param) \
+static ssize_t prefix ## _get_ ## param(struct device *dev, DEVICE_ATTRIBUTE char *buf) \
+{ \
+	return prefix ## _get_param_ ## type(dev, buf, PREFIX ## _ ## param); \
+}
+
+#define LINE6_PARAM_RW(PREFIX, prefix, type, param) \
+LINE6_PARAM_R(PREFIX, prefix, type, param); \
+static ssize_t prefix ## _set_ ## param(struct device *dev, DEVICE_ATTRIBUTE const char *buf, size_t count) \
+{ \
+	return prefix ## _set_param_ ## type(dev, buf, count, PREFIX ## _ ## param); \
+}
+
+#define POD_PARAM_R(type, param) LINE6_PARAM_R(POD, pod, type, param)
+#define POD_PARAM_RW(type, param) LINE6_PARAM_RW(POD, pod, type, param)
+#define VARIAX_PARAM_R(type, param) LINE6_PARAM_R(VARIAX, variax, type, param)
+#define VARIAX_PARAM_RW(type, param) LINE6_PARAM_RW(VARIAX, variax, type, param)
+
+
+static ssize_t pod_get_param_int(struct device *dev, char *buf, int param)
+{
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6_pod *pod = usb_get_intfdata(interface);
+	int retval = line6_wait_dump(&pod->dumpreq, 0);
+	if(retval < 0) return retval;
+	return sprintf(buf, "%d\n", pod->prog_data.control[param]);
+}
+
+static ssize_t pod_set_param_int(struct device *dev, const char *buf, size_t count, int param)
+{
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6_pod *pod = usb_get_intfdata(interface);
+	int value = simple_strtoul(buf, NULL, 10);
+	pod_transmit_parameter(pod, param, value);
+	return count;
+}
+
+static ssize_t variax_get_param_int(struct device *dev, char *buf, int param)
+{
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6_variax *variax = usb_get_intfdata(interface);
+	int retval = line6_wait_dump(&variax->dumpreq, 0);
+	if(retval < 0) return retval;
+	return sprintf(buf, "%d\n", variax->model_data.control[param]);
+}
+
+static ssize_t variax_get_param_float(struct device *dev, char *buf, int param)
+{
+	/*
+		We do our own floating point handling here since floats in the kernel are
+		problematic for at least two reasons:
+		- many distros are still shipped with binary kernels optimized for the
+		  ancient 80386 without FPU
+		- there isn't a printf("%f")
+		  (see http://www.kernelthread.com/publications/faq/335.html)
+	*/
+
+	static const int BIAS = 0x7f;
+	static const int OFFSET = 0xf;
+	static const int PRECISION = 1000;
+
+	int len = 0;
+	unsigned part_int, part_frac;
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6_variax *variax = usb_get_intfdata(interface);
+	const unsigned char *p = variax->model_data.control + param;
+	int retval = line6_wait_dump(&variax->dumpreq, 0);
+	if(retval < 0) return retval;
+
+	if((p[0] == 0) && (p[1] == 0) && (p[2] == 0))
+		part_int = part_frac = 0;
+	else {
+		int exponent = (((p[0] & 0x7f) << 1) | (p[1] >> 7)) - BIAS;
+		unsigned mantissa = (p[1] << 8) | p[2] | 0x8000;
+		exponent -= OFFSET;
+
+		if(exponent >= 0) {
+			part_int = mantissa << exponent;
+			part_frac = 0;
+		}
+		else {
+			part_int = mantissa >> -exponent;
+			part_frac = (mantissa << (32 + exponent)) & 0xffffffff;
+		}
+
+		part_frac = (part_frac / ((1UL << 31) / (PRECISION / 2 * 10)) + 5) / 10;
+	}
+
+	len += sprintf(buf + len, "%s%d.%03d\n", ((p[0] & 0x80) ? "-" : ""), part_int, part_frac);
+	return len;
+}
+
+POD_PARAM_RW(int, tweak);
+POD_PARAM_RW(int, wah_position);
+POD_PARAM_RW(int, compression_gain);
+POD_PARAM_RW(int, vol_pedal_position);
+POD_PARAM_RW(int, compression_threshold);
+POD_PARAM_RW(int, pan);
+POD_PARAM_RW(int, amp_model_setup);
+POD_PARAM_RW(int, amp_model);
+POD_PARAM_RW(int, drive);
+POD_PARAM_RW(int, bass);
+POD_PARAM_RW(int, mid);
+POD_PARAM_RW(int, lowmid);
+POD_PARAM_RW(int, treble);
+POD_PARAM_RW(int, highmid);
+POD_PARAM_RW(int, chan_vol);
+POD_PARAM_RW(int, reverb_mix);
+POD_PARAM_RW(int, effect_setup);
+POD_PARAM_RW(int, band_1_frequency);
+POD_PARAM_RW(int, presence);
+POD_PARAM_RW(int, treble__bass);
+POD_PARAM_RW(int, noise_gate_enable);
+POD_PARAM_RW(int, gate_threshold);
+POD_PARAM_RW(int, gate_decay_time);
+POD_PARAM_RW(int, stomp_enable);
+POD_PARAM_RW(int, comp_enable);
+POD_PARAM_RW(int, stomp_time);
+POD_PARAM_RW(int, delay_enable);
+POD_PARAM_RW(int, mod_param_1);
+POD_PARAM_RW(int, delay_param_1);
+POD_PARAM_RW(int, delay_param_1_note_value);
+POD_PARAM_RW(int, band_2_frequency__bass);
+POD_PARAM_RW(int, delay_param_2);
+POD_PARAM_RW(int, delay_volume_mix);
+POD_PARAM_RW(int, delay_param_3);
+POD_PARAM_RW(int, reverb_enable);
+POD_PARAM_RW(int, reverb_type);
+POD_PARAM_RW(int, reverb_decay);
+POD_PARAM_RW(int, reverb_tone);
+POD_PARAM_RW(int, reverb_pre_delay);
+POD_PARAM_RW(int, reverb_pre_post);
+POD_PARAM_RW(int, band_2_frequency);
+POD_PARAM_RW(int, band_3_frequency__bass);
+POD_PARAM_RW(int, wah_enable);
+POD_PARAM_RW(int, modulation_lo_cut);
+POD_PARAM_RW(int, delay_reverb_lo_cut);
+POD_PARAM_RW(int, volume_pedal_minimum);
+POD_PARAM_RW(int, eq_pre_post);
+POD_PARAM_RW(int, volume_pre_post);
+POD_PARAM_RW(int, di_model);
+POD_PARAM_RW(int, di_delay);
+POD_PARAM_RW(int, mod_enable);
+POD_PARAM_RW(int, mod_param_1_note_value);
+POD_PARAM_RW(int, mod_param_2);
+POD_PARAM_RW(int, mod_param_3);
+POD_PARAM_RW(int, mod_param_4);
+POD_PARAM_RW(int, mod_param_5);
+POD_PARAM_RW(int, mod_volume_mix);
+POD_PARAM_RW(int, mod_pre_post);
+POD_PARAM_RW(int, modulation_model);
+POD_PARAM_RW(int, band_3_frequency);
+POD_PARAM_RW(int, band_4_frequency__bass);
+POD_PARAM_RW(int, mod_param_1_double_precision);
+POD_PARAM_RW(int, delay_param_1_double_precision);
+POD_PARAM_RW(int, eq_enable);
+POD_PARAM_RW(int, tap);
+POD_PARAM_RW(int, volume_tweak_pedal_assign);
+POD_PARAM_RW(int, band_5_frequency);
+POD_PARAM_RW(int, tuner);
+POD_PARAM_RW(int, mic_selection);
+POD_PARAM_RW(int, cabinet_model);
+POD_PARAM_RW(int, stomp_model);
+POD_PARAM_RW(int, roomlevel);
+POD_PARAM_RW(int, band_4_frequency);
+POD_PARAM_RW(int, band_6_frequency);
+POD_PARAM_RW(int, stomp_param_1_note_value);
+POD_PARAM_RW(int, stomp_param_2);
+POD_PARAM_RW(int, stomp_param_3);
+POD_PARAM_RW(int, stomp_param_4);
+POD_PARAM_RW(int, stomp_param_5);
+POD_PARAM_RW(int, stomp_param_6);
+POD_PARAM_RW(int, amp_switch_select);
+POD_PARAM_RW(int, delay_param_4);
+POD_PARAM_RW(int, delay_param_5);
+POD_PARAM_RW(int, delay_pre_post);
+POD_PARAM_RW(int, delay_model);
+POD_PARAM_RW(int, delay_verb_model);
+POD_PARAM_RW(int, tempo_msb);
+POD_PARAM_RW(int, tempo_lsb);
+POD_PARAM_RW(int, wah_model);
+POD_PARAM_RW(int, bypass_volume);
+POD_PARAM_RW(int, fx_loop_on_off);
+POD_PARAM_RW(int, tweak_param_select);
+POD_PARAM_RW(int, amp1_engage);
+POD_PARAM_RW(int, band_1_gain);
+POD_PARAM_RW(int, band_2_gain__bass);
+POD_PARAM_RW(int, band_2_gain);
+POD_PARAM_RW(int, band_3_gain__bass);
+POD_PARAM_RW(int, band_3_gain);
+POD_PARAM_RW(int, band_4_gain__bass);
+POD_PARAM_RW(int, band_5_gain__bass);
+POD_PARAM_RW(int, band_4_gain);
+POD_PARAM_RW(int, band_6_gain__bass);
+VARIAX_PARAM_R(int, body);
+VARIAX_PARAM_R(int, pickup1_enable);
+VARIAX_PARAM_R(int, pickup1_type);
+VARIAX_PARAM_R(float, pickup1_position);
+VARIAX_PARAM_R(float, pickup1_angle);
+VARIAX_PARAM_R(float, pickup1_level);
+VARIAX_PARAM_R(int, pickup2_enable);
+VARIAX_PARAM_R(int, pickup2_type);
+VARIAX_PARAM_R(float, pickup2_position);
+VARIAX_PARAM_R(float, pickup2_angle);
+VARIAX_PARAM_R(float, pickup2_level);
+VARIAX_PARAM_R(int, pickup_phase);
+VARIAX_PARAM_R(float, capacitance);
+VARIAX_PARAM_R(float, tone_resistance);
+VARIAX_PARAM_R(float, volume_resistance);
+VARIAX_PARAM_R(int, taper);
+VARIAX_PARAM_R(float, tone_dump);
+VARIAX_PARAM_R(int, save_tone);
+VARIAX_PARAM_R(float, volume_dump);
+VARIAX_PARAM_R(int, tuning_enable);
+VARIAX_PARAM_R(int, tuning6);
+VARIAX_PARAM_R(int, tuning5);
+VARIAX_PARAM_R(int, tuning4);
+VARIAX_PARAM_R(int, tuning3);
+VARIAX_PARAM_R(int, tuning2);
+VARIAX_PARAM_R(int, tuning1);
+VARIAX_PARAM_R(float, detune6);
+VARIAX_PARAM_R(float, detune5);