dmaengine: dw: extract dwc_chan_pause() for future use

iDMA 32-bit has a special handling of the FIFO during pause() /
terminate_all(). Prepare code to implement that.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dw/core.c

@@ -927,22 +927,26 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
 	return 0;
 }
 
-static int dwc_pause(struct dma_chan *chan)
+static void dwc_chan_pause(struct dw_dma_chan *dwc)
 {
-	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
-	unsigned long		flags;
 	unsigned int		count = 20;	/* timeout iterations */
 	u32			cfglo;
 
-	spin_lock_irqsave(&dwc->lock, flags);
-
 	cfglo = channel_readl(dwc, CFG_LO);
 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
 	while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
 		udelay(2);
 
 	set_bit(DW_DMA_IS_PAUSED, &dwc->flags);
+}
 
+static int dwc_pause(struct dma_chan *chan)
+{
+	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc_chan_pause(dwc);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	return 0;