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iio: adc: at91-sama5d2_adc: disable/prepare buffer on suspend/resume

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[ 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: 073c662017 ("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.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Claudiu Beznea
2022-08-03 13:28:40 +03:00
committed by Greg Kroah-Hartman
parent 513c72d76d
commit 44ec4b04fc
1 changed files with 7 additions and 7 deletions
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14
drivers/iio/adc/at91-sama5d2_adc.c
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@@ -1907,6 +1907,9 @@ static __maybe_unused int at91_adc_suspend(struct device *dev)
struct iio_dev *indio_dev = dev_get_drvdata(dev); struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct at91_adc_state *st = iio_priv(indio_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. * 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 * 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)) if (!iio_buffer_enabled(indio_dev))
return 0; return 0;
/* check if we are enabling triggered buffer or the touchscreen */ ret = at91_adc_buffer_prepare(indio_dev);
if (at91_adc_current_chan_is_touch(indio_dev)) if (ret)
return at91_adc_configure_touch(st, true); goto vref_disable_resume;
else
return at91_adc_configure_trigger(st->trig, true);
/* not needed but more explicit */ return at91_adc_configure_trigger(st->trig, true);
return 0;
vref_disable_resume: vref_disable_resume:
regulator_disable(st->vref); regulator_disable(st->vref);