iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel() (a9ab624e) · Commits · 戴 / test

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>

drivers/iio/adc/stm32-dfsdm-adc.c

+17 −4

Original line number	Diff line number	Diff line
		@@ -1383,9 +1383,13 @@ 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,
		@@ -1509,7 +1513,16 @@ 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;
		}

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