Commit 499da8bd authored by Olivier Moysan's avatar Olivier Moysan Committed by Jonathan Cameron
Browse files

iio: adc: stm32-adc: dma transfers cleanup 



- Remove processing related to DMA in irq handler as this
data transfer is managed directly in DMA callback.
- Update comment in stm32_adc_set_watermark() function.

Signed-off-by: default avatarOlivier Moysan <olivier.moysan@st.com>
Reviewed-by: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Link: https://lore.kernel.org/r/20201105142941.27301-1-olivier.moysan@st.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 7f797115

drivers/iio/adc/stm32-adc.c

+6 −23
Original line number Diff line number Diff line
@@ -1310,7 +1310,7 @@ static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) 
	 * dma cyclic transfers are used, buffer is split into two periods.

	 * There should be :

	 * - always one buffer (period) dma is working on

	 * - one buffer (period) driver can push with iio_trigger_poll().

	 * - one buffer (period) driver can push data.

	 */

	watermark = min(watermark, val * (unsigned)(sizeof(u16)));

	adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
@@ -1573,30 +1573,13 @@ static irqreturn_t stm32_adc_trigger_handler(int irq, void *p) 


	dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);



	if (!adc->dma_chan) {

	/* reset buffer index */

	adc->bufi = 0;

	iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,

					   pf->timestamp);

	} else {

		int residue = stm32_adc_dma_residue(adc);



		while (residue >= indio_dev->scan_bytes) {

			u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];



			iio_push_to_buffers_with_timestamp(indio_dev, buffer,

							   pf->timestamp);

			residue -= indio_dev->scan_bytes;

			adc->bufi += indio_dev->scan_bytes;

			if (adc->bufi >= adc->rx_buf_sz)

				adc->bufi = 0;

		}

	}



	iio_trigger_notify_done(indio_dev->trig);



	/* re-enable eoc irq */

	if (!adc->dma_chan)

	stm32_adc_conv_irq_enable(adc);



	return IRQ_HANDLED;