lcd_dma_descriptor
scr->dma_desc_pa + 2 * sizeof (struct lcd_dma_descriptor));
scr->dma_desc_pa + 1 * sizeof (struct lcd_dma_descriptor));
struct lcd_dma_descriptor *desc;
size = roundup(size,16) + 3 * sizeof(struct lcd_dma_descriptor)
desc = (struct lcd_dma_descriptor *)(
struct lcd_dma_descriptor *dma_desc;