Some I/Os are connected to ADC input channels, when the corresponding bit
in PCSEL register are set on STM32H7 and STM32MP15. This is done in the
prepare routine of stm32-adc driver.
There are constraints here, as PCSEL shouldn't be set when VDDA supply
is disabled. Enabling/disabling of VDDA supply in done via stm32-adc-core
runtime PM routines (before/after ADC is enabled/disabled).
Currently, PCSEL remains set when disabling ADC. Later on, PM runtime
can disable the VDDA supply. This creates some conditions on I/Os that
can start to leak current.
So PCSEL needs to be cleared when disabling the ADC.
Fixes: 95e339b6e85d ("iio: adc: stm32: add support for STM32H7")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
---
drivers/iio/adc/stm32-adc.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 5088de8..e3e7541 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -975,6 +975,7 @@ static void stm32h7_adc_unprepare(struct iio_dev *indio_dev)
{
struct stm32_adc *adc = iio_priv(indio_dev);
+ stm32_adc_writel(adc, STM32H7_ADC_PCSEL, 0);
stm32h7_adc_disable(indio_dev);
stm32h7_adc_enter_pwr_down(adc);
}
--
2.7.4
