snd_midi_channel_alloc_set
struct snd_midi_channel_set *snd_midi_channel_alloc_set(int n);
EXPORT_SYMBOL(snd_midi_channel_alloc_set);
opl3->oss_chset = snd_midi_channel_alloc_set(voices);
opl3->chset = snd_midi_channel_alloc_set(16);
opl4->chset = snd_midi_channel_alloc_set(16);