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authorPeter Ujfalusi <peter.ujfalusi@ti.com>2020-01-07 13:45:32 +0200
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2020-01-12 11:34:08 +0000
commita9ab624edd9186fbad734cfe5d606a6da3ca34db (patch)
tree2c9fc9c135f4df509e78bc8b71bc9f188f937fc0
parente895bc1ebb31750f3baa74e074617d3cc5d0cee2 (diff)
downloadlinux-a9ab624edd9186fbad734cfe5d606a6da3ca34db.tar.gz
iio: adc: stm32-dfsdm: 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: Olivier Moysan <olivier.moysan@st.com> Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
-rw-r--r--drivers/iio/adc/stm32-dfsdm-adc.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index e493242c266e..74a2211bdff4 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -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;
}