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| author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2020-01-08 10:08:01 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-27 17:37:44 +0200 |
| commit | cdaedaba687bdffdbc215a2fb7272cb3f0871921 (patch) | |
| tree | c9b40754afc55f95df354cdd896d67cbd3aab9fa | |
| parent | 754254daca39b9a75c5c2e6e3d9c5d3c7923abed (diff) | |
| download | linux-cdaedaba687bdffdbc215a2fb7272cb3f0871921.tar.gz linux-cdaedaba687bdffdbc215a2fb7272cb3f0871921.tar.bz2 linux-cdaedaba687bdffdbc215a2fb7272cb3f0871921.zip | |
iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel()
[ Upstream commit 735404b846dffcb320264f62b76e6f70012214dd ]
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: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/iio/adc/stm32-adc.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 24d5d049567a..d85caedda02e 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1688,9 +1688,21 @@ static int stm32_adc_dma_request(struct iio_dev *indio_dev) struct dma_slave_config config; int ret; - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); - if (!adc->dma_chan) + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); + if (IS_ERR(adc->dma_chan)) { + ret = PTR_ERR(adc->dma_chan); + if (ret != -ENODEV) { + if (ret != -EPROBE_DEFER) + dev_err(&indio_dev->dev, + "DMA channel request failed with %d\n", + ret); + return ret; + } + + /* DMA is optional: fall back to IRQ mode */ + adc->dma_chan = NULL; return 0; + } adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, |