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
  30 extern struct snd_pcm_ops snd_line6_playback_ops;
  31
  32 extern int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm);
  33 extern int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm);
  34 extern void line6_unlink_audio_out_urbs(struct snd_line6_pcm *line6pcm);
  35 extern void line6_unlink_wait_clear_audio_out_urbs(struct snd_line6_pcm
  36                                                    *line6pcm);
  37 extern int snd_line6_playback_trigger(struct snd_line6_pcm *line6pcm, int cmd);
  38
  39 #endif