MMCCLK_CLKEN
writel(MMCCLK_CLKEN, host->base + DAVINCI_MMCCLK);
temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKEN;
writel(temp | MMCCLK_CLKEN, host->base + DAVINCI_MMCCLK);