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, 398 insertions, 0 deletions

diff --git a/drivers/staging/line6/midi.c b/drivers/staging/line6/midi.c
new file mode 100644
index 00000000000..74489ee77bf
--- /dev/null
+++ b/drivers/staging/line6/midi.c
@@ -0,0 +1,398 @@
+/*
+ * 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 <sound/core.h>
+#include <sound/rawmidi.h>
+
+#include "audio.h"
+#include "midi.h"
+#include "pod.h"
+#include "usbdefs.h"
+
+
+#define USE_MIDIBUF      1
+#define OUTPUT_DUMP_ONLY 0
+
+
+#define line6_rawmidi_substream_midi(substream) ((struct snd_line6_midi *)((substream)->rmidi->private_data))
+
+
+static int send_midi_async(struct usb_line6 *line6, unsigned char *data, int length);
+
+
+/*
+	Pass data received via USB to MIDI.
+*/
+void line6_midi_receive(struct usb_line6 *line6, unsigned char *data, int length)
+{
+	if(line6->line6midi->substream_receive)
+		snd_rawmidi_receive(line6->line6midi->substream_receive, data, length);
+}
+
+/*
+	Read data from MIDI buffer and transmit them via USB.
+*/
+static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
+{
+	struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6;
+	struct snd_line6_midi *line6midi = line6->line6midi;
+	struct MidiBuffer *mb = &line6midi->midibuf_out;
+	unsigned long flags;
+	unsigned char chunk[line6->max_packet_size];
+	int req, done;
+
+	spin_lock_irqsave(&line6->line6midi->midi_transmit_lock, flags);
+
+	for(;;) {
+		req = min(midibuf_bytes_free(mb), line6->max_packet_size);
+		done = snd_rawmidi_transmit_peek(substream, chunk, req);
+
+		if(done == 0)
+			break;
+
+#if DO_DUMP_MIDI_SEND
+		line6_write_hexdump(line6, 's', chunk, done);
+#endif
+		midibuf_write(mb, chunk, done);
+		snd_rawmidi_transmit_ack(substream, done);
+	}
+
+	for(;;) {
+		done = midibuf_read(mb, chunk, line6->max_packet_size);
+
+		if(done == 0)
+			break;
+
+		if(midibuf_skip_message(mb, line6midi->midi_mask_transmit))
+			continue;
+
+		send_midi_async(line6, chunk, done);
+	}
+
+	spin_unlock_irqrestore(&line6->line6midi->midi_transmit_lock, flags);
+}
+
+/*
+	Notification of completion of MIDI transmission.
+*/
+static void midi_sent(struct urb *urb PT_REGS)
+{
+	unsigned long flags;
+	int status;
+	int num;
+	struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
+
+	status = urb->status;
+	kfree(urb->transfer_buffer);
+	usb_free_urb(urb);
+
+	if(status == -ESHUTDOWN)
+		return;
+
+	spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
+	num = --line6->line6midi->num_active_send_urbs;
+
+	if(num == 0) {
+		line6_midi_transmit(line6->line6midi->substream_transmit);
+		num = line6->line6midi->num_active_send_urbs;
+	}
+
+	if(num == 0)
+		wake_up_interruptible(&line6->line6midi->send_wait);
+
+	spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
+}
+
+/*
+	Send an asynchronous MIDI message.
+	Assumes that line6->line6midi->send_urb_lock is held
+	(i.e., this function is serialized).
+*/
+static int send_midi_async(struct usb_line6 *line6, unsigned char *data, int length)
+{
+	struct urb *urb;
+	int retval;
+	unsigned char *transfer_buffer;
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+
+	if(urb == 0) {
+		dev_err(line6->ifcdev, "Out of memory\n");
+		return -ENOMEM;
+	}
+
+#if DO_DUMP_URB_SEND
+	line6_write_hexdump(line6, 'S', data, length);
+#endif
+
+	transfer_buffer = (unsigned char *)kmalloc(length, GFP_ATOMIC);
+
+	if(transfer_buffer == 0) {
+		usb_free_urb(urb);
+		dev_err(line6->ifcdev, "Out of memory\n");
+		return -ENOMEM;
+	}
+
+	memcpy(transfer_buffer, data, length);
+	usb_fill_int_urb(urb,
+									 line6->usbdev,
+									 usb_sndbulkpipe(line6->usbdev, line6->ep_control_write),
+									 transfer_buffer, length, midi_sent, line6, line6->interval);
+	urb->actual_length = 0;
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+
+	if(retval < 0) {
+		dev_err(line6->ifcdev, "usb_submit_urb failed\n");
+		usb_free_urb(urb);
+		return -EINVAL;
+	}
+
+	++line6->line6midi->num_active_send_urbs;
+
+	switch(line6->usbdev->descriptor.idProduct) {
+	case LINE6_DEVID_BASSPODXT:
+	case LINE6_DEVID_BASSPODXTLIVE:
+	case LINE6_DEVID_BASSPODXTPRO:
+	case LINE6_DEVID_PODXT:
+	case LINE6_DEVID_PODXTLIVE:
+	case LINE6_DEVID_PODXTPRO:
+	case LINE6_DEVID_POCKETPOD:
+		pod_midi_postprocess((struct usb_line6_pod *)line6, data, length);
+		break;
+
+	default:
+		MISSING_CASE;
+	}
+
+	return 0;
+}
+
+static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	unsigned long flags;
+	struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6;
+
+	line6->line6midi->substream_transmit = substream;
+	spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
+
+	if(line6->line6midi->num_active_send_urbs == 0)
+		line6_midi_transmit(substream);
+
+	spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
+}
+
+static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
+{
+	struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6;
+	wait_queue_head_t *head = &line6->line6midi->send_wait;
+	DECLARE_WAITQUEUE(wait, current);
+	add_wait_queue(head, &wait);
+	current->state = TASK_INTERRUPTIBLE;
+
+	while(line6->line6midi->num_active_send_urbs > 0)
+		if(signal_pending(current))
+			break;
+		else
+			schedule();
+
+	current->state = TASK_RUNNING;
+	remove_wait_queue(head, &wait);
+}
+
+static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6;
+
+	if(up)
+		line6->line6midi->substream_receive = substream;
+	else
+		line6->line6midi->substream_receive = 0;
+}
+
+static struct snd_rawmidi_ops line6_midi_output_ops = {
+	.open = line6_midi_output_open,
+	.close = line6_midi_output_close,
+	.trigger = line6_midi_output_trigger,
+	.drain = line6_midi_output_drain,
+};
+
+static struct snd_rawmidi_ops line6_midi_input_ops = {
+	.open = line6_midi_input_open,
+	.close = line6_midi_input_close,
+	.trigger = line6_midi_input_trigger,
+};
+
+/*
+	Cleanup the Line6 MIDI device.
+*/
+static void line6_cleanup_midi(struct snd_rawmidi *rmidi)
+{
+}
+
+/* Create a MIDI device */
+static int snd_line6_new_midi(struct snd_line6_midi *line6midi)
+{
+	struct snd_rawmidi *rmidi;
+	int err;
+
+	if((err = snd_rawmidi_new(line6midi->line6->card, "Line6 MIDI", 0, 1, 1, &rmidi)) < 0)
+		return err;
+
+	rmidi->private_data = line6midi;
+	rmidi->private_free = line6_cleanup_midi;
+	strcpy(rmidi->name, line6midi->line6->properties->name);
+
+	rmidi->info_flags =
+		SNDRV_RAWMIDI_INFO_OUTPUT |
+		SNDRV_RAWMIDI_INFO_INPUT |
+		SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &line6_midi_output_ops);
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &line6_midi_input_ops);
+	return 0;
+}
+
+/*
+	"read" request on "midi_mask_transmit" special file.
+*/
+static ssize_t midi_get_midi_mask_transmit(struct device *dev, DEVICE_ATTRIBUTE char *buf)
+{
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6 *line6 = usb_get_intfdata(interface);
+	return sprintf(buf, "%d\n", line6->line6midi->midi_mask_transmit);
+}
+
+/*
+	"write" request on "midi_mask" special file.
+*/
+static ssize_t midi_set_midi_mask_transmit(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);
+	int value = simple_strtoul(buf, NULL, 10);
+	line6->line6midi->midi_mask_transmit = value;
+	return count;
+}
+
+/*
+	"read" request on "midi_mask_receive" special file.
+*/
+static ssize_t midi_get_midi_mask_receive(struct device *dev, DEVICE_ATTRIBUTE char *buf)
+{
+	struct usb_interface *interface = to_usb_interface(dev);
+	struct usb_line6 *line6 = usb_get_intfdata(interface);
+	return sprintf(buf, "%d\n", line6->line6midi->midi_mask_receive);
+}
+
+/*
+	"write" request on "midi_mask" special file.
+*/
+static ssize_t midi_set_midi_mask_receive(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);
+	int value = simple_strtoul(buf, NULL, 10);
+	line6->line6midi->midi_mask_receive = value;
+	return count;
+}
+
+static DEVICE_ATTR(midi_mask_transmit, S_IWUGO | S_IRUGO, midi_get_midi_mask_transmit, midi_set_midi_mask_transmit);
+static DEVICE_ATTR(midi_mask_receive, S_IWUGO | S_IRUGO, midi_get_midi_mask_receive, midi_set_midi_mask_receive);
+
+/* MIDI device destructor */
+static int snd_line6_midi_free(struct snd_device *device)
+{
+	struct snd_line6_midi *line6midi = device->device_data;
+	device_remove_file(line6midi->line6->ifcdev, &dev_attr_midi_mask_transmit);
+	device_remove_file(line6midi->line6->ifcdev, &dev_attr_midi_mask_receive);
+	midibuf_destroy(&line6midi->midibuf_in);
+	midibuf_destroy(&line6midi->midibuf_out);
+	return 0;
+}
+
+/*
+	Initialize the Line6 MIDI subsystem.
+*/
+int line6_init_midi(struct usb_line6 *line6)
+{
+	static struct snd_device_ops midi_ops = {
+		.dev_free = snd_line6_midi_free,
+	};
+
+	int err;
+	struct snd_line6_midi *line6midi;
+
+	if(!(line6->properties->capabilities & LINE6_BIT_CONTROL))
+		return 0;  /* skip MIDI initialization and report success */
+
+	line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
+
+	if(line6midi == NULL)
+		return -ENOMEM;
+
+	err = midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
+
+	if(err < 0)
+		return err;
+
+	err = midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
+
+	if(err < 0)
+		return err;
+
+	line6midi->line6 = line6;
+	line6midi->midi_mask_transmit = 1;
+	line6midi->midi_mask_receive = 4;
+	line6->line6midi = line6midi;
+
+	if((err = snd_device_new(line6->card, SNDRV_DEV_RAWMIDI, line6midi, &midi_ops)) < 0)
+		return err;
+
+	snd_card_set_dev(line6->card, line6->ifcdev);
+
+	if((err = snd_line6_new_midi(line6midi)) < 0)
+		return err;
+
+	if((err = device_create_file(line6->ifcdev, &dev_attr_midi_mask_transmit)) < 0)
+		return err;
+
+	if((err = device_create_file(line6->ifcdev, &dev_attr_midi_mask_receive)) < 0)
+		return err;
+
+	init_waitqueue_head(&line6midi->send_wait);
+	spin_lock_init(&line6midi->send_urb_lock);
+	spin_lock_init(&line6midi->midi_transmit_lock);
+	return 0;
+}