PAD_DAT_RD_RXDLY
regval &= ~(PAD_DAT_RD_RXDLY | PAD_DAT_RD_RXDLY2);
regval |= FIELD_PREP(PAD_DAT_RD_RXDLY, value);
regval |= FIELD_PREP(PAD_DAT_RD_RXDLY, PAD_DELAY_HALF - 1);