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| author | Fabrice Gasnier <fabrice.gasnier@foss.st.com> | 2021-10-22 15:19:29 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-14 13:32:45 +0300 |
| commit | af7fbb8c0b5438494ef5f6474011aebbb42ee00c (patch) | |
| tree | 5fb328bac6525f34d28d3dfb1ed8b6637f6e7c07 | |
| parent | fff92f3712d771103ca967dc8cb1180e5a48078a (diff) | |
| download | linux-af7fbb8c0b5438494ef5f6474011aebbb42ee00c.tar.xz | |
iio: adc: stm32: fix a current leak by resetting pcsel before disabling vdda
commit f711f28e71e965c0d1141c830fa7131b41abbe75 upstream.
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>
Reviewed-by: Olivier Moysan <olivier.moysan@foss.st.com>
Link: https://lore.kernel.org/r/1634905169-23762-1-git-send-email-fabrice.gasnier@foss.st.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/iio/adc/stm32-adc.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 16c02c30dec7..9939dee01743 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -979,6 +979,7 @@ 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); } |