OPL3SA2_MISC
tmp = snd_opl3sa2_read(chip, OPL3SA2_MISC);
snd_opl3sa2_write(chip, OPL3SA2_MISC, tmp ^ 7);
tmp1 = snd_opl3sa2_read(chip, OPL3SA2_MISC);
snd_opl3sa2_write(chip, OPL3SA2_MISC, 0x80 | (tmp & 7)); /* Miscellaneous - default */