mmc_set_bus_mode
void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode);
mmc_set_bus_mode(host, MMC_BUSMODE_OPENDRAIN);
mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
mmc_set_bus_mode(host, MMC_BUSMODE_OPENDRAIN);