[PATCH] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()

From: Peter Ujfalusi
Date: Tue Dec 17 2019 - 02:52:17 EST


dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
drivers/iio/adc/stm32-dfsdm-adc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index e493242c266e..3aac1a21f9d0 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -1383,9 +1383,9 @@ static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);

- adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
- if (!adc->dma_chan)
- return -EINVAL;
+ adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx");
+ if (IS_ERR(adc->dma_chan))
+ return PTR_ERR(adc->dma_chan);

adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
DFSDM_DMA_BUFFER_SIZE,
--
Peter

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