REG_SLAVE
regmap_read(spifc->regmap, REG_SLAVE, &data);
regmap_update_bits(spifc->regmap, REG_SLAVE, SLAVE_TRST_DONE, 0);
regmap_update_bits(spifc->regmap, REG_SLAVE, SLAVE_SW_RST,
regmap_update_bits(spifc->regmap, REG_SLAVE, SLAVE_OP_MODE, 0);