SDDMA_GCR
writel(DMA_GCR_SOFT_RESET, priv->sdmmc_base + SDDMA_GCR);
writel(DMA_GCR_DMA_EN, priv->sdmmc_base + SDDMA_GCR);
if ((readl(priv->sdmmc_base + SDDMA_GCR) & DMA_GCR_DMA_EN) != 0)