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, 210 insertions, 0 deletions

diff --git a/drivers/staging/line6/pcm.h b/drivers/staging/line6/pcm.h
new file mode 100644
index 00000000000..90f8bb9816d
--- /dev/null
+++ b/drivers/staging/line6/pcm.h
@@ -0,0 +1,210 @@
+/*
+ * 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.
+ *
+ */
+
+/*
+	PCM interface to POD series devices.
+*/
+
+#ifndef PCM_H
+#define PCM_H
+
+
+#include <sound/pcm.h>
+
+#include "driver.h"
+#include "usbdefs.h"
+
+
+#define LINE6_ISO_BUFFERS 8  /* number of URBs */
+#define LINE6_ISO_PACKETS 2  /* number of USB frames per URB */
+#define LINE6_ISO_INTERVAL 1  /* in a "full speed" device (such as the PODxt Pro) this means 1ms */
+#define LINE6_ISO_PACKET_SIZE_MAX 252  /* this should be queried dynamically from the USB interface! */
+
+
+/*
+	Extract the messaging device from the substream instance
+*/
+#define s2m(s) (((struct snd_line6_pcm *)snd_pcm_substream_chip(s))->line6->ifcdev)
+
+
+enum {
+	BIT_RUNNING_PLAYBACK,
+	BIT_RUNNING_CAPTURE,
+	BIT_PAUSE_PLAYBACK,
+	BIT_PREPARED
+};
+
+struct line6_pcm_properties {
+	struct snd_pcm_hardware snd_line6_playback_hw, snd_line6_capture_hw;
+	struct snd_pcm_hw_constraint_ratdens snd_line6_rates;
+	int bytes_per_frame;
+};
+
+struct snd_line6_pcm
+{
+	/**
+		 Pointer back to the Line6 driver data structure.
+	*/
+	struct usb_line6 *line6;
+
+	/**
+		 Properties.
+	*/
+	struct line6_pcm_properties *properties;
+
+	/**
+		 ALSA pcm stream
+	*/
+	struct snd_pcm *pcm;
+
+	/**
+		 URBs for audio playback.
+	*/
+	struct urb *urb_audio_out[LINE6_ISO_BUFFERS];
+
+	/**
+		 URBs for audio capture.
+	*/
+	struct urb *urb_audio_in[LINE6_ISO_BUFFERS];
+
+	/**
+		 Temporary buffer to hold data when playback buffer wraps.
+	*/
+	unsigned char *wrap_out;
+
+	/**
+		 Temporary buffer for capture.
+		 Since the packet size is not known in advance, this buffer is large enough
+		 to store maximum size packets.
+	*/
+	unsigned char *buffer_in;
+
+	/**
+		 Free frame position in the playback buffer.
+	*/
+	snd_pcm_uframes_t pos_out;
+
+	/**
+		 Count processed bytes for playback.
+		 This is modulo period size (to determine when a period is finished).
+	*/
+	unsigned bytes_out;
+
+	/**
+		 Counter to create desired playback sample rate.
+	*/
+	unsigned count_out;
+
+	/**
+		 Playback period size in bytes
+	*/
+	unsigned period_out;
+
+	/**
+		 Processed frame position in the playback buffer.
+		 The contents of the output ring buffer have been consumed by the USB
+		 subsystem (i.e., sent to the USB device) up to this position.
+	*/
+	snd_pcm_uframes_t pos_out_done;
+
+	/**
+		 Count processed bytes for capture.
+		 This is modulo period size (to determine when a period is finished).
+	*/
+	unsigned bytes_in;
+
+	/**
+		 Counter to create desired capture sample rate.
+	*/
+	unsigned count_in;
+
+	/**
+		 Capture period size in bytes
+	*/
+	unsigned period_in;
+
+	/**
+		 Processed frame position in the capture buffer.
+		 The contents of the output ring buffer have been consumed by the USB
+		 subsystem (i.e., sent to the USB device) up to this position.
+	*/
+	snd_pcm_uframes_t pos_in_done;
+
+	/**
+		 Bit mask of active playback URBs.
+	*/
+	unsigned long active_urb_out;
+
+	/**
+		 Maximum size of USB packet.
+	*/
+	int max_packet_size;
+
+	/**
+		 USB endpoint for listening to audio data.
+	*/
+	int ep_audio_read;
+
+	/**
+		 USB endpoint for writing audio data.
+	*/
+	int ep_audio_write;
+
+	/**
+		 Bit mask of active capture URBs.
+	*/
+	unsigned long active_urb_in;
+
+	/**
+		 Bit mask of playback URBs currently being unlinked.
+	*/
+	unsigned long unlink_urb_out;
+
+	/**
+		 Bit mask of capture URBs currently being unlinked.
+	*/
+	unsigned long unlink_urb_in;
+
+	/**
+		 Spin lock to protect updates of the playback buffer positions (not
+		 contents!)
+	*/
+	spinlock_t lock_audio_out;
+
+	/**
+		 Spin lock to protect updates of the capture buffer positions (not
+		 contents!)
+	*/
+	spinlock_t lock_audio_in;
+
+	/**
+		 Spin lock to protect trigger.
+	*/
+	spinlock_t lock_trigger;
+
+	/**
+		 PCM playback volume (left and right).
+	*/
+	int volume[2];
+
+	/**
+		 Several status bits (see BIT_*).
+	*/
+	unsigned long flags;
+};
+
+
+extern int line6_init_pcm(struct usb_line6 *line6, struct line6_pcm_properties *properties);
+extern int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd);
+extern int snd_line6_prepare(struct snd_pcm_substream *substream);
+
+
+#endif