dmaengine: dw: Reset DRAIN bit when resume the channel

For Intel iDMA 32-bit the channel can be drained on a suspend.
We need to reset the bit on the resume to return a status quo.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dw/dw.c

@@ -35,6 +35,13 @@ static void dw_dma_suspend_chan(struct dw_dma_chan *dwc, bool drain)
 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
 }
 
+static void dw_dma_resume_chan(struct dw_dma_chan *dwc, bool drain)
+{
+	u32 cfglo = channel_readl(dwc, CFG_LO);
+
+	channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
+}
+
 static u32 dw_dma_bytes2block(struct dw_dma_chan *dwc,
 			      size_t bytes, unsigned int width, size_t *len)
 {
@@ -91,6 +98,7 @@ int dw_dma_probe(struct dw_dma_chip *chip)
 	/* Channel operations */
 	dw->initialize_chan = dw_dma_initialize_chan;
 	dw->suspend_chan = dw_dma_suspend_chan;
+	dw->resume_chan = dw_dma_resume_chan;
 	dw->encode_maxburst = dw_dma_encode_maxburst;
 	dw->bytes2block = dw_dma_bytes2block;
 	dw->block2bytes = dw_dma_block2bytes;