[PATCH] iio: adc: at91: Use dma_request_chan() instead dma_request_slave_channel()

From: Peter Ujfalusi
Date: Tue Dec 17 2019 - 02:50:42 EST


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@xxxxxx>
---
drivers/iio/adc/at91-sama5d2_adc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index e1850f3d5cf3..a5c7771227d5 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -1444,10 +1444,10 @@ static void at91_adc_dma_init(struct platform_device *pdev)
if (st->dma_st.dma_chan)
return;

- st->dma_st.dma_chan = dma_request_slave_channel(&pdev->dev, "rx");
-
- if (!st->dma_st.dma_chan) {
+ st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx");
+ if (IS_ERR(st->dma_st.dma_chan)) {
dev_info(&pdev->dev, "can't get DMA channel\n");
+ st->dma_st.dma_chan = NULL;
goto dma_exit;
}

--
Peter

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