From: Claudiu Beznea claudiu.beznea@microchip.com
[ Upstream commit 808175e21d9b7f866eda742e8970f27b78afe5db ]
In case triggered buffers are enabled while system is suspended they will not work anymore after resume. For this call at91_adc_buffer_postdisable() on suspend and at91_adc_buffer_prepare() on resume. On tests it has been seen that at91_adc_buffer_postdisable() call is not necessary but it has been kept because it also does the book keeping for DMA. On resume path there is no need to call at91_adc_configure_touch() as it is embedded in at91_adc_buffer_prepare().
Fixes: 073c662017f2f ("iio: adc: at91-sama5d2_adc: add support for DMA") Signed-off-by: Claudiu Beznea claudiu.beznea@microchip.com Link: https://lore.kernel.org/r/20220803102855.2191070-5-claudiu.beznea@microchip.... Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/adc/at91-sama5d2_adc.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index ef6dc85024c1..250b78ee1625 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -1907,6 +1907,9 @@ static __maybe_unused int at91_adc_suspend(struct device *dev) struct iio_dev *indio_dev = dev_get_drvdata(dev); struct at91_adc_state *st = iio_priv(indio_dev);
+ if (iio_buffer_enabled(indio_dev)) + at91_adc_buffer_postdisable(indio_dev); + /* * Do a sofware reset of the ADC before we go to suspend. * this will ensure that all pins are free from being muxed by the ADC @@ -1950,14 +1953,11 @@ static __maybe_unused int at91_adc_resume(struct device *dev) if (!iio_buffer_enabled(indio_dev)) return 0;
- /* check if we are enabling triggered buffer or the touchscreen */ - if (at91_adc_current_chan_is_touch(indio_dev)) - return at91_adc_configure_touch(st, true); - else - return at91_adc_configure_trigger(st->trig, true); + ret = at91_adc_buffer_prepare(indio_dev); + if (ret) + goto vref_disable_resume;
- /* not needed but more explicit */ - return 0; + return at91_adc_configure_trigger(st->trig, true);
vref_disable_resume: regulator_disable(st->vref);