[PATCH] iio: adc: stm32: fix minimum sampling time values

[PATCH] iio: adc: stm32: fix minimum sampling time values

[Fabrice Gasnier]

From: Cheick Traore <cheick.traore-ext@st.com>

- On stm32mp15: vddcpu and vddq_ddr are not connected to internal
channel, so their sampling time shouldn't be set.

- On stm32mp13: vddcpu and vddq_ddr are connected to internal channels
and the value for vddcore was not correct. Values from the datasheet
are 1us (e.g. 1000ns) for ts_vddcore, ts_vddcpu and ts_vddq_ddr.

Fixes: 7cb2303dd024 ("iio: adc: stm32: manage min sampling time on all internal channels")
Cc: stable@vger.kernel.org
Signed-off-by: Cheick Traore <cheick.traore-ext@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
---
 drivers/iio/adc/stm32-adc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 90f0e257e6d1..b024326775ae 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -2734,7 +2734,7 @@ static const struct stm32_adc_cfg stm32h7_adc_cfg = {
 	.set_ovs = stm32h7_adc_set_ovs,
 };
 
-static const unsigned int stm32_adc_min_ts_mp1[] = { 100, 100, 100, 4300, 9800 };
+static const unsigned int stm32_adc_min_ts_mp1[] = { 100, 0, 0, 4300, 9800 };
 static_assert(ARRAY_SIZE(stm32_adc_min_ts_mp1) == STM32_ADC_INT_CH_NB);
 
 static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
@@ -2756,7 +2756,7 @@ static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
 	.set_ovs = stm32h7_adc_set_ovs,
 };
 
-static const unsigned int stm32_adc_min_ts_mp13[] = { 100, 0, 0, 4300, 9800 };
+static const unsigned int stm32_adc_min_ts_mp13[] = { 1000, 1000, 1000, 4300, 9800 };
 static_assert(ARRAY_SIZE(stm32_adc_min_ts_mp13) == STM32_ADC_INT_CH_NB);
 
 static const struct stm32_adc_cfg stm32mp13_adc_cfg = {

---
base-commit: 182c47735554925da9605dc9dd90a8c15a1bbae5
change-id: 20260924-adc-fix-sampling-526f0f26829b

Best regards,
--  
Fabrice Gasnier <fabrice.gasnier@foss.st.com>

Re: [PATCH] iio: adc: stm32: fix minimum sampling time values

[Jonathan Cameron]

On Thu, 24 Sep 2026 11:53:56 +0200
Fabrice Gasnier <fabrice.gasnier@foss.st.com> wrote:

> From: Cheick Traore <cheick.traore-ext@st.com>
> 
> - On stm32mp15: vddcpu and vddq_ddr are not connected to internal
> channel, so their sampling time shouldn't be set.
> 
> - On stm32mp13: vddcpu and vddq_ddr are connected to internal channels
> and the value for vddcore was not correct. Values from the datasheet
> are 1us (e.g. 1000ns) for ts_vddcore, ts_vddcpu and ts_vddq_ddr.
> 
> Fixes: 7cb2303dd024 ("iio: adc: stm32: manage min sampling time on all internal channels")
> Cc: stable@vger.kernel.org
> Signed-off-by: Cheick Traore <cheick.traore-ext@st.com>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Hi Cheick, Fabrice

Given we are fairly late in the cycle and that we have Fabrice's
other series poking at this same driver I've queued this up on
the testing branch of iio.git rather than taking a (possibly) faster
path.  That means it will go upstream in the next merge window.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/stm32-adc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index 90f0e257e6d1..b024326775ae 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -2734,7 +2734,7 @@ static const struct stm32_adc_cfg stm32h7_adc_cfg = {
>  	.set_ovs = stm32h7_adc_set_ovs,
>  };
>  
> -static const unsigned int stm32_adc_min_ts_mp1[] = { 100, 100, 100, 4300, 9800 };
> +static const unsigned int stm32_adc_min_ts_mp1[] = { 100, 0, 0, 4300, 9800 };
>  static_assert(ARRAY_SIZE(stm32_adc_min_ts_mp1) == STM32_ADC_INT_CH_NB);
>  
>  static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
> @@ -2756,7 +2756,7 @@ static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
>  	.set_ovs = stm32h7_adc_set_ovs,
>  };
>  
> -static const unsigned int stm32_adc_min_ts_mp13[] = { 100, 0, 0, 4300, 9800 };
> +static const unsigned int stm32_adc_min_ts_mp13[] = { 1000, 1000, 1000, 4300, 9800 };
>  static_assert(ARRAY_SIZE(stm32_adc_min_ts_mp13) == STM32_ADC_INT_CH_NB);
>  
>  static const struct stm32_adc_cfg stm32mp13_adc_cfg = {
> 
> ---
> base-commit: 182c47735554925da9605dc9dd90a8c15a1bbae5
> change-id: 20260924-adc-fix-sampling-526f0f26829b
> 
> Best regards,
> --  
> Fabrice Gasnier <fabrice.gasnier@foss.st.com>
>