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authorPeter Ujfalusi <peter.ujfalusi@ti.com>2020-01-08 10:08:01 +0200
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2020-01-12 11:34:09 +0000
commit735404b846dffcb320264f62b76e6f70012214dd (patch)
tree2563970ae631dc8ed95d655626f509e144544710 /drivers/iio/adc
parenta9ab624edd9186fbad734cfe5d606a6da3ca34db (diff)
downloadlinux-735404b846dffcb320264f62b76e6f70012214dd.tar.gz
iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel()
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>
Diffstat (limited to 'drivers/iio/adc')
-rw-r--r--drivers/iio/adc/stm32-adc.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 5f05bf9f16ea..80c3f963527b 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -1796,9 +1796,21 @@ 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,