TWSI_BAUDRATE
gttwsi_write_4(sc, TWSI_BAUDRATE, baud);
[TWSI_BAUDRATE] = TWSI_ALLWINNER_BAUDRATE,
baud = gttwsi_read_4(sc, TWSI_BAUDRATE);
[TWSI_BAUDRATE] = TWSI_MARVELL_BAUDRATE,