[PATCH 4/4] ASoC: ti: davinci-mcasp: Use dmaengine_get_provider_device() API

[Frank.Li@oss.nxp.com]

From: Frank Li <Frank.Li@nxp.com>

Replace open-coded chan->device->dev with dmaengine_get_provider_device()
to avoid direct access to DMA engine internals. The WARN_ON check for
chan->device is no longer needed since already checked return value of
dma_request_chan(). It is impossible dma_chan is not NULL and DMA engine
device is NULL.

Prepare to make struct dma_device private.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 sound/soc/ti/davinci-mcasp.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/sound/soc/ti/davinci-mcasp.c b/sound/soc/ti/davinci-mcasp.c
index 481d1042ddb6d..e871925517dca 100644
--- a/sound/soc/ti/davinci-mcasp.c
+++ b/sound/soc/ti/davinci-mcasp.c
@@ -2477,6 +2477,7 @@ static const char *sdma_prefix = "ti,omap";
 static int davinci_mcasp_get_dma_type(struct davinci_mcasp *mcasp)
 {
 	struct dma_chan *chan;
+	struct device *dma_dev;
 	const char *tmp;
 	int ret = PCM_EDMA;
 
@@ -2488,13 +2489,10 @@ static int davinci_mcasp_get_dma_type(struct davinci_mcasp *mcasp)
 	if (IS_ERR(chan))
 		return dev_err_probe(mcasp->dev, PTR_ERR(chan),
 				     "Can't verify DMA configuration\n");
-	if (WARN_ON(!chan->device || !chan->device->dev)) {
-		dma_release_channel(chan);
-		return -EINVAL;
-	}
 
-	if (chan->device->dev->of_node)
-		ret = of_property_read_string(chan->device->dev->of_node,
+	dma_dev = dmaengine_get_provider_device(chan);
+	if (dma_dev->of_node)
+		ret = of_property_read_string(dma_dev->of_node,
 					      "compatible", &tmp);
 	else
 		dev_dbg(mcasp->dev, "DMA controller has no of-node\n");

-- 
2.43.0