dmaengine: sh: rcar-dmac: add a new function to clear CHCR.DE with barrier

This patch adds a new function rcar_dmac_clear_chcr_de() to simplify
adding pause function later.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sh/rcar-dmac.c

@@ -759,18 +759,25 @@ static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan)
 	dev_err(chan->chan.device->dev, "CHCR DE check error\n");
 }
 
-static void rcar_dmac_sync_tcr(struct rcar_dmac_chan *chan)
+static void rcar_dmac_clear_chcr_de(struct rcar_dmac_chan *chan)
 {
 	u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
 
-	if (!(chcr & RCAR_DMACHCR_DE))
-		return;
-
 	/* set DE=0 and flush remaining data */
 	rcar_dmac_chan_write(chan, RCAR_DMACHCR, (chcr & ~RCAR_DMACHCR_DE));
 
 	/* make sure all remaining data was flushed */
 	rcar_dmac_chcr_de_barrier(chan);
+}
+
+static void rcar_dmac_sync_tcr(struct rcar_dmac_chan *chan)
+{
+	u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
+
+	if (!(chcr & RCAR_DMACHCR_DE))
+		return;
+
+	rcar_dmac_clear_chcr_de(chan);
 
 	/* back DE if remain data exists */
 	if (rcar_dmac_chan_read(chan, RCAR_DMATCR))