SDHC_VOLTAGE_SHIFT
SDHC_VOLTAGE_1_8V << (SDHC_VOLTAGE_SHIFT + 8));
~(SDHC_BUS_POWER | (SDHC_VOLTAGE_MASK << SDHC_VOLTAGE_SHIFT));
(vdd << SDHC_VOLTAGE_SHIFT) | SDHC_BUS_POWER);
reg |= (vdd << SDHC_VOLTAGE_SHIFT);