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

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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: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-6-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Claudiu Beznea 2022-08-03 13:28:41 +03:00 committed by Jonathan Cameron
parent 808175e21d
commit cf15a2b518
1 changed files with 10 additions and 0 deletions
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10
drivers/iio/adc/at91-sama5d2_adc.c
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@ -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;