LXR linux/drivers/staging/line6/playback.h

   1/*
   2 * Line6 Linux USB driver - 0.9.1beta
   3 *
   4 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5 *
   6 *      This program is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU General Public License as
   8 *      published by the Free Software Foundation, version 2.
   9 *
  10 */
  11
  12#ifndef PLAYBACK_H
  13#define PLAYBACK_H
  14
  15#include <sound/pcm.h>
  16
  17#include "driver.h"
  18
  19/*
  20 * When the TonePort is used with jack in full duplex mode and the outputs are
  21 * not connected, the software monitor produces an ugly noise since everything
  22 * written to the output buffer (i.e., the input signal) will be repeated in
  23 * the next period (sounds like a delay effect). As a workaround, the output
  24 * buffer is cleared after the data have been read, but there must be a better
  25 * solution. Until one is found, this workaround can be used to fix the
  26 * problem.
  27 */
  28#define USE_CLEAR_BUFFER_WORKAROUND 1
  29
  30extern struct snd_pcm_ops snd_line6_playback_ops;
  31
  32extern int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm);
  33extern void line6_free_playback_buffer(struct snd_line6_pcm *line6pcm);
  34extern int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm);
  35extern void line6_unlink_audio_out_urbs(struct snd_line6_pcm *line6pcm);
  36extern void line6_unlink_wait_clear_audio_out_urbs(struct snd_line6_pcm
  37                                                   *line6pcm);
  38extern void line6_wait_clear_audio_out_urbs(struct snd_line6_pcm *line6pcm);
  39extern int snd_line6_playback_trigger(struct snd_line6_pcm *line6pcm, int cmd);
  40
  41#endif
  42