DMA_MST_CTRL
writel_relaxed(DMA_MST_CTRL_IS_DONE, ctrl->regs + DMA_MST_CTRL);
dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
writel_relaxed(0, ctrl->regs + DMA_MST_CTRL);
dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
writel_relaxed(dma_ctrl, ctrl->regs + DMA_MST_CTRL);