SDMMC_MUL
rate *= SDMMC_MUL;
req->rate = DIV_ROUND_UP(output_rate * SDMMC_MUL,
div + SDMMC_MUL);
req->rate = output_rate * SDMMC_MUL / (div + SDMMC_MUL);
div += SDMMC_MUL;