alsa-utils/alsactl/setup.c

/*
 *  Advanced Linux Sound Architecture Control Program
 *  Copyright (c) 1997 by Perex, APS, University of South Bohemia
 *
 *
 *   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; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include "alsactl.h"

#define SND_INTERFACE_CONTROL	0
#define SND_INTERFACE_MIXER	1
#define SND_INTERFACE_PCM	2
#define SND_INTERFACE_RAWMIDI	3

extern int yyparse( void );
extern int linecount;
extern FILE *yyin;
extern int yydebug;
struct soundcard *soundcards = NULL;

/*
 *  free functions
 */

static void soundcard_ctl_switch_free( struct ctl_switch *first )
{
  struct ctl_switch *next;

  while ( first ) {
    next = first -> next;
    free( first );
    first = next;
  }
}

static void soundcard_mixer_channel_free( struct mixer_channel *first )
{
  struct mixer_channel *next;

  while ( first ) {
    next = first -> next;
    free( first );
    first = next;
  }
}

static void soundcard_mixer_switch_free( struct mixer_switch *first )
{
  struct mixer_switch *next;

  while ( first ) {
    next = first -> next;
    free( first );
    first = next;
  }
}

static void soundcard_mixer_free1( struct mixer *mixer )
{
  if ( !mixer ) return;
  soundcard_mixer_channel_free( mixer -> channels );
  soundcard_mixer_switch_free( mixer -> switches );
  free( mixer );
}
 
static void soundcard_mixer_free( struct mixer *first )
{
  struct mixer *next;

  while ( first ) {
    next = first -> next;
    soundcard_mixer_free1( first );
    first = next;
  }
}

static void soundcard_pcm_switch_free( struct pcm_switch *first )
{
  struct pcm_switch *next;

  while ( first ) {
    next = first -> next;
    free( first );
    first = next;
  }
}

static void soundcard_pcm_free1( struct pcm *pcm )
{
  if ( !pcm ) return;
  soundcard_pcm_switch_free( pcm -> pswitches );
  soundcard_pcm_switch_free( pcm -> rswitches );
  free( pcm );
}
 
static void soundcard_pcm_free( struct pcm *first )
{
  struct pcm *next;

  while ( first ) {
    next = first -> next;
    soundcard_pcm_free1( first );
    first = next;
  }
}

static void soundcard_rawmidi_switch_free( struct rawmidi_switch *first )
{
  struct rawmidi_switch *next;

  while ( first ) {
    next = first -> next;
    free( first );
    first = next;
  }
}

static void soundcard_rawmidi_free1( struct rawmidi *rawmidi )
{
  if ( !rawmidi ) return;
  soundcard_rawmidi_switch_free( rawmidi -> iswitches );
  soundcard_rawmidi_switch_free( rawmidi -> oswitches );
  free( rawmidi );
}
 
static void soundcard_rawmidi_free( struct rawmidi *first )
{
  struct rawmidi *next;

  while ( first ) {
    next = first -> next;
    soundcard_rawmidi_free1( first );
    first = next;
  }
}

static void soundcard_free1( struct soundcard *soundcard )
{
  if ( !soundcard ) return;
  soundcard_ctl_switch_free( soundcard -> control.switches );
  soundcard_mixer_free( soundcard -> mixers );
  soundcard_pcm_free( soundcard -> pcms );
  soundcard_rawmidi_free( soundcard -> rawmidis );
  free( soundcard );
}

static void soundcard_free( struct soundcard *first )
{
  struct soundcard *next;

  while ( first ) {
    next = first -> next;
    soundcard_free1( first );
    first = next;
  }
}

static int soundcard_remove( int cardno )
{
  struct soundcard *first, *prev = NULL, *next;
  
  first = soundcards;
  while ( first ) {
    next = first -> next;
    if ( first -> no == cardno ) {
      soundcard_free1( first );
      if ( !prev ) soundcards = next; else prev -> next = next;
      return 0;
    }
    prev = first;
    first = first -> next;
  }
  return -1;
}

/*
 *  exported functions
 */

void soundcard_setup_init( void )
{
  soundcards = NULL;
}

void soundcard_setup_done( void )
{
  soundcard_free( soundcards ); soundcards = NULL;
}

int soundcard_setup_collect( int cardno )
{
  void *handle, *mhandle;
  struct soundcard *card, *first, *prev;
  int err, idx, count, device;
  struct ctl_switch *ctl, *ctlprev;
  struct mixer *mixer, *mixerprev;
  struct mixer_switch *mixsw, *mixswprev;
  struct mixer_channel *mixerchannel, *mixerchannelprev;
  struct pcm *pcm, *pcmprev;
  struct pcm_switch *pcmsw, *pcmswprev;
  struct rawmidi *rawmidi, *rawmidiprev;
  struct rawmidi_switch *rawmidisw, *rawmidiswprev;

  soundcard_remove( cardno );
  if ( (err = snd_ctl_open( &handle, cardno )) < 0 ) {
    error( "SND CTL open error: %s", snd_strerror( err ) );
    return 1;
  }
  /* --- */
  card = (struct soundcard *)malloc( sizeof( struct soundcard ) );
  if ( !card ) {
    snd_ctl_close( handle );
    error( "malloc error" );
    return 1;
  }
  bzero( card, sizeof( struct soundcard ) );
  card -> no = cardno;
  for ( first = soundcards, prev = NULL; first; prev = first, first = first -> next )
    if ( first -> no > cardno ) {
      if ( !prev ) {
        soundcards = card;
      } else {
        prev -> next = card;
      }
      card -> next = first;
      break;
    }
  if ( !soundcards ) soundcards = card;
  if ( (err = snd_ctl_hw_info( handle, &card -> control.hwinfo )) < 0 ) {
    snd_ctl_close( handle );
    error( "SND CTL HW INFO error: %s", snd_strerror( err ) );
    return 1;
  }
  /* --- */
  count = snd_ctl_switches( handle );
  for ( idx = 0, ctlprev = NULL; idx < count; idx++ ) {
    ctl = (struct ctl_switch *)malloc( sizeof( struct ctl_switch ) );
    if ( !ctl ) {
      snd_ctl_close( handle );
      error( "malloc error" );
      return 1;
    }
    bzero( ctl, sizeof( struct ctl_switch ) );
    ctl -> no = idx;
    if ( (err = snd_ctl_switch_read( handle, idx, &ctl -> s )) < 0 ) {
      free( ctl );
      snd_ctl_close( handle );
      error( "CTL switch read error (%s) - skipping" );
      break;
    }
    if ( !ctlprev ) {
      card -> control.switches = ctl;
    } else {
      ctlprev -> next = ctl;
    }
    ctlprev = ctl;
  }
  /* --- */
  for ( device = 0, mixerprev = NULL; device < card -> control.hwinfo.mixerdevs; device++ ) {
    mixer = (struct mixer *)malloc( sizeof( struct mixer ) );
    if ( !mixer ) {
      snd_ctl_close( handle );
      error( "malloc problem" );
      return 1;
    }
    bzero( mixer, sizeof( struct mixer ) );
    mixer -> no = device;
    count = snd_ctl_mixer_switches( handle, device );
    for ( idx = 0, mixswprev = NULL; idx < count; idx++ ) {
      mixsw = (struct mixer_switch *)malloc( sizeof( struct mixer_switch ) );
      if ( !mixsw ) {
        snd_ctl_close( handle );
        error( "malloc error" );
        return 1;
      }
      bzero( mixsw, sizeof( struct mixer_switch ) );
      mixsw -> no = idx;
      if ( (err = snd_ctl_mixer_switch_read( handle, device, idx, &mixsw -> s )) < 0 ) {
        free( mixsw );
        error( "MIXER switch read error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( !mixswprev ) {
        mixer -> switches = mixsw;
      } else {
        mixswprev -> next = mixsw;
      }
      mixswprev = mixsw;
    }
    if ( !mixerprev ) {
      card -> mixers = mixer;
    } else {
      mixerprev -> next = mixer;
    }
    mixerprev = mixer;
    if ( (err = snd_mixer_open( &mhandle, cardno, device )) < 0 ) {
      snd_ctl_close( handle );
      error( "MIXER open error: %s\n", snd_strerror( err ) );
      return 1;
    }
    if ( (err = snd_mixer_exact_mode( mhandle, 1 )) < 0 ) {
      snd_mixer_close( mhandle );
      snd_ctl_close( handle );
      error( "MIXER exact mode error: %s\n", snd_strerror( err ) );
      return 1;
    }
    if ( (err = snd_mixer_info( mhandle, &mixer -> info )) < 0 ) {
      snd_mixer_close( mhandle );
      snd_ctl_close( handle );
      error( "MIXER info error: %s\n", snd_strerror( err ) );
      return 1;
    }
    count = snd_mixer_channels( mhandle );
    for ( idx = 0, mixerchannelprev = NULL; idx < count; idx++ ) {
      mixerchannel = (struct mixer_channel *)malloc( sizeof( struct mixer_channel ) );
      if ( !mixerchannel ) {
        snd_mixer_close( mhandle );
        snd_ctl_close( handle );
        error( "malloc problem" );
        return 1;
      }
      bzero( mixerchannel, sizeof( struct mixer_channel ) );
      mixerchannel -> no = idx;
      if ( (err = snd_mixer_channel_info( mhandle, idx, &mixerchannel -> i )) < 0 ) {
        free( mixerchannel );
        error( "MIXER channel info error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( (err = snd_mixer_channel_read( mhandle, idx, &mixerchannel -> c )) < 0 ) {
        free( mixerchannel );
        error( "MIXER channel read error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( !mixerchannelprev ) {
        mixer -> channels = mixerchannel;
      } else {
        mixerchannelprev -> next = mixerchannel;
      }
      mixerchannelprev = mixerchannel;
    }
    snd_mixer_close( mhandle );
  }
  /* --- */
  for ( device = 0, pcmprev = NULL; device < card -> control.hwinfo.pcmdevs; device++ ) {
    pcm = (struct pcm *)malloc( sizeof( struct pcm ) );
    if ( !pcm ) {
      snd_ctl_close( handle );
      error( "malloc problem" );
      return 1;
    }
    bzero( pcm, sizeof( struct pcm ) );
    pcm -> no = device;
    if ( (err = snd_ctl_pcm_info( handle, device, &pcm -> info )) < 0 ) {
      snd_ctl_close( handle );
      error( "PCM info error: %s\n", snd_strerror( err ) );
      return 1;
    }
    count = snd_ctl_pcm_playback_switches( handle, device );
    for ( idx = 0, pcmswprev = NULL; idx < count; idx++ ) {
      pcmsw = (struct pcm_switch *)malloc( sizeof( struct pcm_switch ) );
      if ( !pcmsw ) {
        snd_ctl_close( handle );
        error( "malloc error" );
        return 1;
      }
      bzero( pcmsw, sizeof( struct mixer_switch ) );
      pcmsw -> no = idx;
      if ( (err = snd_ctl_pcm_playback_switch_read( handle, device, idx, &pcmsw -> s )) < 0 ) {
        free( pcmsw );
        error( "PCM playback switch read error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( !pcmswprev ) {
        pcm -> pswitches = pcmsw;
      } else {
        pcmswprev -> next = pcmsw;
      }
      pcmswprev = pcmsw;
    }
    count = snd_ctl_pcm_record_switches( handle, device );
    for ( idx = 0, pcmswprev = NULL; idx < count; idx++ ) {
      pcmsw = (struct pcm_switch *)malloc( sizeof( struct pcm_switch ) );
      if ( !pcmsw ) {
        snd_ctl_close( handle );
        error( "malloc error" );
        return 1;
      }
      bzero( pcmsw, sizeof( struct mixer_switch ) );
      pcmsw -> no = idx;
      if ( (err = snd_ctl_pcm_record_switch_read( handle, device, idx, &pcmsw -> s )) < 0 ) {
        free( pcmsw );
        error( "PCM record switch read error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( !pcmswprev ) {
        pcm -> rswitches = pcmsw;
      } else {
        pcmswprev -> next = pcmsw;
      }
      pcmswprev = pcmsw;
    }
    if ( !pcmprev ) {
      card -> pcms = pcm;
    } else {
      pcmprev -> next = pcm;
    }
    pcmprev = pcm;
  }
  /* --- */
  for ( device = 0, rawmidiprev = NULL; device < card -> control.hwinfo.mididevs; device++ ) {
    rawmidi = (struct rawmidi *)malloc( sizeof( struct rawmidi ) );
    if ( !rawmidi ) {
      snd_ctl_close( handle );
      error( "malloc problem" );
      return 1;
    }
    bzero( rawmidi, sizeof( struct rawmidi ) );
    rawmidi -> no = device;
    if ( (err = snd_ctl_rawmidi_info( handle, device, &rawmidi -> info )) < 0 ) {
      snd_ctl_close( handle );
      error( "RAWMIDI info error: %s\n", snd_strerror( err ) );
      return 1;
    }
    count = snd_ctl_rawmidi_input_switches( handle, device );
    for ( idx = 0, rawmidiswprev = NULL; idx < count; idx++ ) {
      rawmidisw = (struct rawmidi_switch *)malloc( sizeof( struct rawmidi_switch ) );
      if ( !rawmidisw ) {
        snd_ctl_close( handle );
        error( "malloc error" );
        return 1;
      }
      bzero( rawmidisw, sizeof( struct rawmidi_switch ) );
      rawmidisw -> no = idx;
      if ( (err = snd_ctl_rawmidi_input_switch_read( handle, device, idx, &rawmidisw -> s )) < 0 ) {
        free( rawmidisw );
        error( "RAWMIDI input switch read error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( !rawmidiswprev ) {
        rawmidi -> iswitches = rawmidisw;
      } else {
        rawmidiswprev -> next = rawmidisw;
      }
      rawmidiswprev = rawmidisw;
    }
    count = snd_ctl_rawmidi_output_switches( handle, device );
    for ( idx = 0, rawmidiswprev = NULL; idx < count; idx++ ) {
      rawmidisw = (struct rawmidi_switch *)malloc( sizeof( struct rawmidi_switch ) );
      if ( !rawmidisw ) {
        snd_ctl_close( handle );
        error( "malloc error" );
        return 1;
      }
      bzero( rawmidisw, sizeof( struct rawmidi_switch ) );
      rawmidisw -> no = idx;
      if ( (err = snd_ctl_rawmidi_output_switch_read( handle, device, idx, &rawmidisw -> s )) < 0 ) {
        free( rawmidisw );
        error( "RAWMIDI output switch read error (%s) - skipping", snd_strerror( err ) );
        break;
      }
      if ( !rawmidiswprev ) {
        rawmidi -> oswitches = rawmidisw;
      } else {
        rawmidiswprev -> next = rawmidisw;
      }
      rawmidiswprev = rawmidisw;
    }
    if ( !rawmidiprev ) {
      card -> rawmidis = rawmidi;
    } else {
      rawmidiprev -> next = rawmidi;
    }
    rawmidiprev = rawmidi;
  }
  /* --- */
  snd_ctl_close( handle );
  return 0;
}

int soundcard_setup_load( const char *cfgfile )
{
  extern int yyparse( void );
  extern int linecount;
  extern FILE *yyin;
  extern int yydebug;
  int xtry;

#ifdef YYDEBUG
  yydebug = 1;  
#endif
  if ( debugflag )
    printf( "cfgfile = '%s'\n", cfgfile );
  if ( ( yyin = fopen( cfgfile, "r" ) ) == NULL ) {
    error( "Cannot open configuration file '%s'...", cfgfile );
    return 1;
  }
  linecount = 0;
  xtry = yyparse();
  fclose( yyin );
  if ( debugflag )
    printf( "Config ok..\n" );
  if ( xtry )
    error( "Ignored error in configuration file '%s'...", cfgfile );
  return 0;
}

static void soundcard_setup_write_switch( FILE *out, int interface, const unsigned char *name, unsigned int type, unsigned int low, unsigned int high, void *data )
{
  struct data {
    unsigned int enable;
    unsigned char data8[32];
    unsigned short data16[16];
    unsigned int data32[8];
  };
  char *s, v[16];
  struct data *pdata = (struct data *)data;
  int idx;
  
  v[0] = '\0';
  switch ( type ) {
    case SND_CTL_SW_TYPE_BOOLEAN: 	s = "bool"; strcpy( v, pdata -> enable ? "true" : "false" ); break;
    case SND_CTL_SW_TYPE_BYTE:		s = "byte"; sprintf( v, "%ui", (unsigned int)pdata -> data8[0] ); break;
    case SND_CTL_SW_TYPE_WORD:		s = "word"; sprintf( v, "%ui", (unsigned int)pdata -> data16[0] ); break;
    case SND_CTL_SW_TYPE_DWORD:		s = "dword"; sprintf( v, "%ui", pdata -> data32[0] ); break;
    case SND_CTL_SW_TYPE_USER:		s = "user"; break;
    default:
      s = "unknown";
  }
  fprintf( out, "    ; Type is '%s'.\n", s );
  if ( low != 0 || high != 0 )
    fprintf( out, "    ; Accepted switch range is from %ui to %ui.\n", low, high );
  fprintf( out, "    switch( \"%s\", %s", name, v );
  if ( type < 0 || type > SND_CTL_SW_TYPE_DWORD ) {
    /* TODO: some well known types should be verbose */
    fprintf( out, " rawdata( " );
    for ( idx = 0; idx < 31; idx++ ) {
      fprintf( out, "@%02x:", pdata -> data8[idx] );
    }
    fprintf( out, "%02x@ )\n", pdata -> data8[31] );
  }
  fprintf( out, " )\n" );
}


static void soundcard_setup_write_mixer_channel( FILE *out, snd_mixer_channel_info_t *info, snd_mixer_channel_t *channel )
{
  fprintf( out, "    ; Capabilities:%s%s%s%s%s%s.\n",
  	info -> caps & SND_MIXER_CINFO_CAP_RECORD ? " record" : "",
  	info -> caps & SND_MIXER_CINFO_CAP_STEREO ? " stereo" : "",
  	info -> caps & SND_MIXER_CINFO_CAP_HWMUTE ? " hardware-mute" : "",
  	info -> caps & SND_MIXER_CINFO_CAP_MONOMUTE ? " mono-mute" : "",
  	info -> caps & SND_MIXER_CINFO_CAP_DIGITAL ? " digital" : "",
  	info -> caps & SND_MIXER_CINFO_CAP_INPUT ? " external-input" : "" );
  fprintf( out, "    ; Accepted channel range is from %i to %i.\n", info -> min, info -> max );
  fprintf( out, "    channel( \"%s\", ", info -> name );
  if ( info -> caps & SND_MIXER_CINFO_CAP_STEREO ) {
    fprintf( out, "stereo( %s%i, %s%i )", channel -> flags & SND_MIXER_FLG_MUTE_LEFT ? "!" : "", channel -> left, channel -> flags & SND_MIXER_FLG_MUTE_RIGHT ? "!" : "", channel -> right );
  } else {
    fprintf( out, "mono( %s%i )", channel -> flags & SND_MIXER_FLG_MUTE ? "!" : "", channel -> left );
  }
  if ( channel -> flags & SND_MIXER_FLG_RECORD )
    fprintf( out, " record" );
  fprintf( out, " )\n" );
}

int soundcard_setup_write( const char *cfgfile )
{
  FILE *out;
  struct soundcard *first;
  struct ctl_switch *ctlsw;
  struct mixer *mixer;
  struct mixer_switch *mixersw;
  struct mixer_channel *mixerchannel;
  struct pcm *pcm;
  struct pcm_switch *pcmsw;
  struct rawmidi *rawmidi;
  struct rawmidi_switch *rawmidisw;
  
  if ( (out = fopen( cfgfile, "w+" )) == NULL ) {
    error( "Cannot open file '%s' for writing...\n", cfgfile );
    return 1;
  }
  fprintf( out, "# ALSA driver configuration\n" );
  fprintf( out, "# Generated by alsactl\n" );
  fprintf( out, "\n" );
  for ( first = soundcards; first; first = first -> next ) {
    fprintf( out, "soundcard( \"%s\" ) {\n", first -> control.hwinfo.id );
    if ( first -> control.switches ) {
      fprintf( out, "  control {\n" );
      for ( ctlsw = first -> control.switches; ctlsw; ctlsw = ctlsw -> next )
        soundcard_setup_write_switch( out, SND_INTERFACE_CONTROL, ctlsw -> s.name, ctlsw -> s.type, ctlsw -> s.low, ctlsw -> s.high, (void *)&ctlsw -> s.value );
      fprintf( out, "  }\n" );
    }
    for ( mixer = first -> mixers; mixer; mixer = mixer -> next ) {
      fprintf( out, "  mixer( \"%s\" ) {\n", mixer -> info.name );
      for ( mixerchannel = mixer -> channels; mixerchannel; mixerchannel = mixerchannel -> next )
        soundcard_setup_write_mixer_channel( out, &mixerchannel -> i, &mixerchannel -> c );
      for ( mixersw = mixer -> switches; mixersw; mixersw = mixersw -> next )
        soundcard_setup_write_switch( out, SND_INTERFACE_MIXER, mixersw -> s.name, mixersw -> s.type, mixersw -> s.low, mixersw -> s.high, (void *)&mixersw -> s.value );
      fprintf( out, "  }\n" );
    }
    for ( pcm = first -> pcms; pcm; pcm = pcm -> next ) {
      if ( !pcm -> pswitches && !pcm -> rswitches ) continue; 
      fprintf( out, "  pcm( \"%s\" ) {\n", pcm -> info.name );
      if ( pcm -> pswitches ) {
        fprintf( out, "    playback {" );
        for ( pcmsw = pcm -> pswitches; pcmsw; pcmsw = pcmsw -> next )
          soundcard_setup_write_switch( out, SND_INTERFACE_PCM, pcmsw -> s.name, pcmsw -> s.type, pcmsw -> s.low, pcmsw -> s.high, (void *)&pcmsw -> s.value );
        fprintf( out, "    }\n" );
      }
      if ( pcm -> rswitches ) {
        fprintf( out, "    record {" );
        for ( pcmsw = pcm -> pswitches; pcmsw; pcmsw = pcmsw -> next )
          soundcard_setup_write_switch( out, SND_INTERFACE_PCM, pcmsw -> s.name, pcmsw -> s.type, pcmsw -> s.low, pcmsw -> s.high, (void *)&pcmsw -> s.value );
        fprintf( out, "    }\n" );
      }
      fprintf( out, "  }\n" );
    }
    for ( rawmidi = first -> rawmidis; rawmidi; rawmidi = rawmidi -> next ) {
      if ( !rawmidi -> oswitches && !rawmidi -> iswitches ) continue;
      fprintf( out, "  rawmidi( \"%s\" ) {\n", rawmidi -> info.name );
      if ( rawmidi -> oswitches ) {
        fprintf( out, "    output {" );
        for ( rawmidisw = rawmidi -> oswitches; rawmidisw; rawmidisw = rawmidisw -> next )
          soundcard_setup_write_switch( out, SND_INTERFACE_RAWMIDI, rawmidisw -> s.name, rawmidisw -> s.type, rawmidisw -> s.low, rawmidisw -> s.high, (void *)&rawmidisw -> s.value );
        fprintf( out, "    }\n" );
      }
      if ( rawmidi -> iswitches ) {
        fprintf( out, "    input {" );
        for ( rawmidisw = rawmidi -> iswitches; rawmidisw; rawmidisw = rawmidisw -> next )
          soundcard_setup_write_switch( out, SND_INTERFACE_RAWMIDI, rawmidisw -> s.name, rawmidisw -> s.type, rawmidisw -> s.low, rawmidisw -> s.high, (void *)&rawmidisw -> s.value );
        fprintf( out, "    }\n" );
      }
      fprintf( out, "  }\n" );
    }
    fprintf( out, "}\n%s", first -> next ? "\n" : "" );
  }
  fclose( out );
  return 0;
}

static int soundcard_open_ctl( void **ctlhandle, struct soundcard *soundcard )
{
  int err;

  if ( *ctlhandle ) return 0;
  if ( (err = snd_ctl_open( ctlhandle, soundcard -> no )) < 0 ) {
    error( "Cannot open control interface for soundcard #%i.", soundcard -> no + 1 );
    return 1;
  }
  return 0;
}

static int soundcard_open_mix( void **mixhandle, struct soundcard *soundcard, struct mixer *mixer )
{
  int err;

  if ( *mixhandle ) return 0;
  if ( (err = snd_mixer_open( mixhandle, soundcard -> no, mixer -> no )) < 0 ) {
    error( "Cannot open mixer interface for soundcard #%i.", soundcard -> no + 1 );
    return 1;
  }
  if ( (err = snd_mixer_exact_mode( *mixhandle, 1 )) < 0 ) {
    error( "Cannot setup exact mode for mixer #%i/#%i: %s", soundcard -> no + 1, mixer -> no, snd_strerror( err ) );
    return 1;
  }
  return 0;
}

int soundcard_setup_process( int cardno )
{
  int err;
  void *ctlhandle = NULL;
  void *mixhandle = NULL;
  struct soundcard *soundcard;
  struct ctl_switch *ctlsw;
  struct mixer *mixer;
  struct mixer_channel *channel;
  struct mixer_switch *mixersw;
  struct pcm *pcm;
  struct pcm_switch *pcmsw;
  struct rawmidi *rawmidi;
  struct rawmidi_switch *rawmidisw;
  
  for ( soundcard = soundcards; soundcard; soundcard = soundcard -> next ) {
    if ( cardno >= 0 && soundcard -> no != cardno ) continue;
    for ( ctlsw = soundcard -> control.switches; ctlsw; ctlsw = ctlsw -> next ) {
      if ( ctlsw -> change )
        if ( !soundcard_open_ctl( &ctlhandle, soundcard ) ) {
          if ( (err = snd_ctl_switch_write( ctlhandle, ctlsw -> no, &ctlsw -> s )) < 0 )
            error( "Control switch '%s' write error: %s", ctlsw -> s.name, snd_strerror( err ) );
        }
    }
    for ( mixer = soundcard -> mixers; mixer; mixer = mixer -> next ) {
      for ( channel = mixer -> channels; channel; channel = channel -> next )
        if ( channel -> change )
          if ( !soundcard_open_mix( &mixhandle, soundcard, mixer ) ) {
            if ( (err = snd_mixer_channel_write( mixhandle, channel -> no, &channel -> c )) < 0 )
              error( "Mixer channel '%s' write error: %s", channel -> i.name, snd_strerror( err ) );
          }
      if ( mixhandle ) { snd_mixer_close( mixhandle ); mixhandle = NULL; }
      for ( mixersw = mixer -> switches; mixersw; mixersw = mixersw -> next )
        if ( mixersw -> change )
          if ( !soundcard_open_ctl( &ctlhandle, soundcard ) ) {
            if ( (err = snd_ctl_mixer_switch_write( ctlhandle, mixer -> no, mixersw -> no, &mixersw -> s )) < 0 )
              error( "Mixer switch '%s' write error: %s", mixersw -> s.name, snd_strerror( err ) );
          }
    }
    for ( pcm = soundcard -> pcms; pcm; pcm = pcm -> next ) {
      for ( pcmsw = pcm -> pswitches; pcmsw; pcmsw = pcmsw -> next ) {
        if ( pcmsw -> change )
          if ( !soundcard_open_ctl( &ctlhandle, soundcard ) ) {
            if ( (err = snd_ctl_pcm_playback_switch_write( ctlhandle, pcm -> no, pcmsw -> no, &pcmsw -> s )) < 0 )
              error( "PCM playback switch '%s' write error: %s", pcmsw -> s.name, snd_strerror( err ) );
          }
      }
      for ( pcmsw = pcm -> rswitches; pcmsw; pcmsw = pcmsw -> next ) {
        if ( pcmsw -> change )
          if ( !soundcard_open_ctl( &ctlhandle, soundcard ) ) {
            if ( (err = snd_ctl_pcm_playback_switch_write( ctlhandle, pcm -> no, pcmsw -> no, &pcmsw -> s )) < 0 )
              error( "PCM record switch '%s' write error: %s", pcmsw -> s.name, snd_strerror( err ) );
          }
      }
    }
    for ( rawmidi = soundcard -> rawmidis; rawmidi; rawmidi = rawmidi -> next ) {
      for ( rawmidisw = rawmidi -> oswitches; rawmidisw; rawmidisw = rawmidisw -> next ) {
        if ( rawmidisw -> change )
          if ( !soundcard_open_ctl( &ctlhandle, soundcard ) ) {
            if ( (err = snd_ctl_rawmidi_output_switch_write( ctlhandle, rawmidi -> no, rawmidisw -> no, &rawmidisw -> s )) < 0 )
              error( "RAWMIDI output switch '%s' write error: %s", rawmidisw -> s.name, snd_strerror( err ) );
          }
      }
      for ( rawmidisw = rawmidi -> iswitches; rawmidisw; rawmidisw = rawmidisw -> next ) {
        if ( rawmidisw -> change )
          if ( !soundcard_open_ctl( &ctlhandle, soundcard ) ) {
            if ( (err = snd_ctl_rawmidi_output_switch_write( ctlhandle, rawmidi -> no, rawmidisw -> no, &rawmidisw -> s )) < 0 )
              error( "RAWMIDI input switch '%s' write error: %s", rawmidisw -> s.name, snd_strerror( err ) );
          }
      }
    }
  }
  if ( ctlhandle ) snd_ctl_close( ctlhandle );
  return 1;
}