iio: adc: at91-sama5d2_adc: ack DRDY irq in direct mode

Need to acknowledge DRDY irq in direct mode/ software
triggered mode. Otherwise, on the next conversion, overrun
flag will be raised, which is not a correct state.
This doesn't affect the functionality, but will generate
possible incorrect overrun reports.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 99f3c2c..4eff835 100644 (file)
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -786,6 +786,9 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
                at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
                at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
 
+               /* Needed to ACK the DRDY interruption */
+               at91_adc_readl(st, AT91_SAMA5D2_LCDR);
+
                mutex_unlock(&st->lock);
 
                iio_device_release_direct_mode(indio_dev);