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

[ Upstream commit a9ab624edd9186fbad734cfe5d606a6da3ca34db ]

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@ti.com>
Acked-by: Olivier Moysan <olivier.moysan@st.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index f5586dd6414d2c579b0c7c927c8d58e37fea92ca..516d7d22d9f48bfc8c8b6cbdf757a8112743e25b 100644 (file)
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -933,9 +933,13 @@ static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
        };
        int ret;
 
-       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)) {
+               int ret = PTR_ERR(adc->dma_chan);
+
+               adc->dma_chan = NULL;
+               return ret;
+       }
 
        adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
                                         DFSDM_DMA_BUFFER_SIZE,