Commit cf15a2b5 authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Jonathan Cameron
Browse files

iio: adc: at91-sama5d2_adc: exit from write_raw() when buffers are enabled 



When buffers are enabled conversion may start asynchronously thus
allowing changes on actual hardware could lead to bad behavior. Thus
do not allow changing oversampling ratio and sample frequency when
if iio_device_claim_direct_mode() returns with error.

Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-6-claudiu.beznea@microchip.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 808175e2

drivers/iio/adc/at91-sama5d2_adc.c

+10 −0
Original line number Diff line number Diff line
@@ -1641,6 +1641,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, 
			      int val, int val2, long mask)

{

	struct at91_adc_state *st = iio_priv(indio_dev);

	int ret;



	switch (mask) {

	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -1650,20 +1651,29 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, 
		/* if no change, optimize out */

		if (val == st->oversampling_ratio)

			return 0;



		ret = iio_device_claim_direct_mode(indio_dev);

		if (ret)

			return ret;

		mutex_lock(&st->lock);

		st->oversampling_ratio = val;

		/* update ratio */

		at91_adc_config_emr(st);

		mutex_unlock(&st->lock);

		iio_device_release_direct_mode(indio_dev);

		return 0;

	case IIO_CHAN_INFO_SAMP_FREQ:

		if (val < st->soc_info.min_sample_rate ||

		    val > st->soc_info.max_sample_rate)

			return -EINVAL;



		ret = iio_device_claim_direct_mode(indio_dev);

		if (ret)

			return ret;

		mutex_lock(&st->lock);

		at91_adc_setup_samp_freq(indio_dev, val);

		mutex_unlock(&st->lock);

		iio_device_release_direct_mode(indio_dev);

		return 0;

	default:

		return -EINVAL;