snd_opti9xx_write
snd_opti9xx_write(chip, reg, (oldval & ~mask) | (value & mask));
snd_opti9xx_write(chip, OPTi9XX_MC_REG(3), (irq_bits << 3 | dma_bits));
snd_opti9xx_write(chip, OPTi9XX_MC_REG(7), 0xff - value);