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authorFabrice Gasnier <fabrice.gasnier@foss.st.com>2021-10-22 14:19:29 +0200
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2021-11-17 18:52:34 +0100
commitf711f28e71e965c0d1141c830fa7131b41abbe75 (patch)
treef52e8da190e80a3b0d3f9bcbb03c18b898fb69b7 /drivers
parentiio: mma8452: Fix trigger reference couting (diff)
downloadlinux-f711f28e71e965c0d1141c830fa7131b41abbe75.tar.xz
linux-f711f28e71e965c0d1141c830fa7131b41abbe75.zip
iio: adc: stm32: fix a current leak by resetting pcsel before disabling vdda
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iio/adc/stm32-adc.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 6245434f8377..60f2ccf7e342 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -1117,6 +1117,7 @@ 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);
stm32_adc_int_ch_disable(adc);
stm32h7_adc_enter_pwr_down(adc);