NPCM_I2CTXF_STS
ioread8(bus->reg + NPCM_I2CTXF_STS));
ioread8(bus->reg + NPCM_I2CTXF_STS);
tx_fifo_sts = ioread8(bus->reg + NPCM_I2CTXF_STS);
val = ioread8(bus->reg + NPCM_I2CTXF_STS);
iowrite8(val, bus->reg + NPCM_I2CTXF_STS);