HW_APBHX_CTRL1
completed = readl(mxs_dma->base + HW_APBHX_CTRL1);
mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR);
mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_SET);