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, 143 insertions, 0 deletions

diff --git a/drivers/staging/line6/dumprequest.c b/drivers/staging/line6/dumprequest.c
new file mode 100644
index 000000000000..89bc0994d07b
--- /dev/null
+++ b/drivers/staging/line6/dumprequest.c
@@ -0,0 +1,143 @@
+/*
+ * 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 "dumprequest.h"
+
+
+/*
+	Set "dump in progress" flag.
+*/
+void line6_dump_started(struct line6_dump_request *l6dr, int dest)
+{
+	l6dr->in_progress = dest;
+}
+
+/*
+	Invalidate current channel, i.e., set "dump in progress" flag.
+	Reading from the "dump" special file blocks until dump is completed.
+*/
+void line6_invalidate_current(struct line6_dump_request *l6dr)
+{
+	line6_dump_started(l6dr, LINE6_DUMP_CURRENT);
+}
+
+/*
+	Clear "dump in progress" flag and notify waiting processes.
+*/
+void line6_dump_finished(struct line6_dump_request *l6dr)
+{
+	l6dr->in_progress = LINE6_DUMP_NONE;
+	wake_up_interruptible(&l6dr->wait);
+}
+
+/*
+	Send an asynchronous channel dump request.
+*/
+int line6_dump_request_async(struct line6_dump_request *l6dr, struct usb_line6 *line6, int num)
+{
+	int ret;
+	line6_invalidate_current(l6dr);
+	ret = line6_send_raw_message_async(line6, l6dr->reqbufs[num].buffer, l6dr->reqbufs[num].length);
+
+	if(ret < 0)
+		line6_dump_finished(l6dr);
+
+	return ret;
+}
+
+/*
+	Send an asynchronous dump request after a given interval.
+*/
+void line6_startup_delayed(struct line6_dump_request *l6dr, int seconds,
+													 void (*function)(unsigned long), void *data)
+{
+	l6dr->timer.expires = jiffies + seconds * HZ;
+	l6dr->timer.function = function;
+	l6dr->timer.data = (unsigned long)data;
+	add_timer(&l6dr->timer);
+}
+
+/*
+	Wait for completion.
+*/
+int line6_wait_dump(struct line6_dump_request *l6dr, int nonblock)
+{
+	int retval = 0;
+	DECLARE_WAITQUEUE(wait, current);
+	add_wait_queue(&l6dr->wait, &wait);
+	current->state = TASK_INTERRUPTIBLE;
+
+	while(l6dr->in_progress) {
+		if(nonblock) {
+			retval = -EAGAIN;
+			break;
+		}
+
+		if(signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+		else
+			schedule();
+	}
+
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&l6dr->wait, &wait);
+	return retval;
+}
+
+/*
+	Initialize dump request buffer.
+*/
+int line6_dumpreq_initbuf(struct line6_dump_request *l6dr, const void *buf, size_t len, int num)
+{
+	l6dr->reqbufs[num].buffer = kmalloc(len, GFP_KERNEL);
+	if(l6dr->reqbufs[num].buffer == NULL) return -ENOMEM;
+	memcpy(l6dr->reqbufs[num].buffer, buf, len);
+	l6dr->reqbufs[num].length = len;
+	return 0;
+}
+
+/*
+	Initialize dump request data structure (including one buffer).
+*/
+int line6_dumpreq_init(struct line6_dump_request *l6dr, const void *buf, size_t len)
+{
+	int ret;
+	ret = line6_dumpreq_initbuf(l6dr, buf, len, 0);
+	if(ret < 0) return ret;
+	init_waitqueue_head(&l6dr->wait);
+	init_timer(&l6dr->timer);
+	return 0;
+}
+
+/*
+	Destruct dump request data structure.
+*/
+void line6_dumpreq_destructbuf(struct line6_dump_request *l6dr, int num)
+{
+	if(l6dr == NULL) return;
+	if(l6dr->reqbufs[num].buffer == NULL) return;
+	kfree(l6dr->reqbufs[num].buffer);
+	l6dr->reqbufs[num].buffer = NULL;
+}
+
+/*
+	Destruct dump request data structure.
+*/
+void line6_dumpreq_destruct(struct line6_dump_request *l6dr)
+{
+	if(l6dr->reqbufs[0].buffer == NULL) return;
+	line6_dumpreq_destructbuf(l6dr, 0);
+	l6dr->ok = 1;
+	del_timer_sync(&l6dr->timer);
+}