REG_SW_GLOBAL_SERIAL_CTRL_0
ret = ksz_read8(dev, REG_SW_GLOBAL_SERIAL_CTRL_0, &data8);
ret = ksz_write8(dev, REG_SW_GLOBAL_SERIAL_CTRL_0, data8);
regmap_update_bits(ksz_regmap_8(dev), REG_SW_GLOBAL_SERIAL_CTRL_0,