| Message ID | 20200108080801.14144-1-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 735404b846dffcb320264f62b76e6f70012214dd |
| Headers | show |
| Series | [v3] iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel() | expand |
On Wed, 8 Jan 2020 10:08:01 +0200 Peter Ujfalusi <peter.ujfalusi@ti.com> wrote: > 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> Applied to the togreg branch of iio.git and pushed out as testing. thanks, Jonathan > --- > Hi, > > Changes since v2: > - Replace the comment as suggested by Fabrice > > Changes since v1: > - Fall back to IRQ mode only in case of ENODEV > > Regards, > Peter > > drivers/iio/adc/stm32-adc.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > index 3b291d72701c..a8d2414ee2eb 100644 > --- a/drivers/iio/adc/stm32-adc.c > +++ b/drivers/iio/adc/stm32-adc.c > @@ -1746,9 +1746,21 @@ 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,
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 3b291d72701c..a8d2414ee2eb 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1746,9 +1746,21 @@ 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,