dma: mxs-dma: convert to clk_prepare/clk_unprepare

The patch converts mxs-dma driver to clk_prepare/clk_unprepare by
using helper functions clk_prepare_enable/clk_disable_unprepare.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>

drivers/dma/mxs-dma.c

@@ -334,7 +334,7 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
 			goto err_irq;
 	}
 
-	ret = clk_enable(mxs_dma->clk);
+	ret = clk_prepare_enable(mxs_dma->clk);
 	if (ret)
 		goto err_clk;
 
@@ -372,7 +372,7 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan)
 	dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
 			mxs_chan->ccw, mxs_chan->ccw_phys);
 
-	clk_disable(mxs_dma->clk);
+	clk_disable_unprepare(mxs_dma->clk);
 }
 
 static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
@@ -578,7 +578,7 @@ static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
 {
 	int ret;
 
-	ret = clk_enable(mxs_dma->clk);
+	ret = clk_prepare_enable(mxs_dma->clk);
 	if (ret)
 		goto err_out;
 
@@ -604,7 +604,7 @@ static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
 	writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS,
 		mxs_dma->base + HW_APBHX_CTRL1 + MXS_SET_ADDR);
 
-	clk_disable(mxs_dma->clk);
+	clk_disable_unprepare(mxs_dma->clk);
 
 	return 0;