Messages in this thread | | | Subject | Re: [PATCH] iio: adc: stm32: fix a leak by resetting pcsel before disabling vdda | From | Olivier MOYSAN <> | Date | Fri, 22 Oct 2021 14:38:52 +0200 |
| |
Hi Fabrice,
On 10/22/21 2:19 PM, Fabrice Gasnier wrote: > 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@foss.st.com> > --- > 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); > } >
Reviewed-by: Olivier Moysan <olivier.moysan@foss.st.com>
Thanks Olivier
| |