diff mbox series

[5.4,104/111] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()

Message ID 20200526183942.740998047@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH May 26, 2020, 6:54 p.m. UTC 
From: Peter Ujfalusi <peter.ujfalusi@ti.com>

[ 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>
---
 drivers/iio/adc/stm32-dfsdm-adc.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 3ae0366a7b58..4a9337a3f9a3 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -1363,9 +1363,13 @@  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)) {
+		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,
@@ -1489,7 +1493,16 @@  static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
 	init_completion(&adc->completion);
 
 	/* Optionally request DMA */
-	if (stm32_dfsdm_dma_request(indio_dev)) {
+	ret = stm32_dfsdm_dma_request(indio_dev);
+	if (ret) {
+		if (ret != -ENODEV) {
+			if (ret != -EPROBE_DEFER)
+				dev_err(&indio_dev->dev,
+					"DMA channel request failed with %d\n",
+					ret);
+			return ret;
+		}
+
 		dev_dbg(&indio_dev->dev, "No DMA support\n");
 		return 0;
 	}