ARM: dts: at91: sama7g5ek: enable pull-up on flexcom3 console lines

[PATCH] ARM: dts: at91: sama7g5ek: enable pull-up on flexcom3 console lines

Posted by Eugen Hristev 4 years, 3 months ago

Flexcom3 is used as board console serial. There are no pull-ups on these
lines on the board. This means that if a cable is not connected (that has
pull-ups included), stray characters could appear on the console as the
floating pins voltage levels are interpreted as incoming characters.
To avoid this problem, enable the internal pull-ups on these lines.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
 arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
index 08685a10eda1d..dd047a8523907 100644
--- a/arch/arm/boot/dts/at91-sama7g5ek.dts
+++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
@@ -495,7 +495,7 @@ pinctrl_flx0_default: flx0_default {
 	pinctrl_flx3_default: flx3_default {
 		pinmux = <PIN_PD16__FLEXCOM3_IO0>,
 			 <PIN_PD17__FLEXCOM3_IO1>;
-		bias-disable;
+		bias-pull-up;
 	};
 
 	pinctrl_flx4_default: flx4_default {
-- 
2.25.1

Re: [PATCH] ARM: dts: at91: sama7g5ek: enable pull-up on flexcom3 console lines

Posted by Tudor.Ambarus@microchip.com 4 years, 3 months ago

On 3/7/22 13:38, Eugen Hristev wrote:
> Flexcom3 is used as board console serial. There are no pull-ups on these
> lines on the board. This means that if a cable is not connected (that has
> pull-ups included), stray characters could appear on the console as the
> floating pins voltage levels are interpreted as incoming characters.
> To avoid this problem, enable the internal pull-ups on these lines.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>

Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>

> ---
>  arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
> index 08685a10eda1d..dd047a8523907 100644
> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
> @@ -495,7 +495,7 @@ pinctrl_flx0_default: flx0_default {
>  	pinctrl_flx3_default: flx3_default {
>  		pinmux = <PIN_PD16__FLEXCOM3_IO0>,
>  			 <PIN_PD17__FLEXCOM3_IO1>;
> -		bias-disable;
> +		bias-pull-up;
>  	};
>  
>  	pinctrl_flx4_default: flx4_default {

Re: [PATCH] ARM: dts: at91: sama7g5ek: enable pull-up on flexcom3 console lines

Posted by Nicolas Ferre 4 years, 2 months ago

On 08/03/2022 at 09:21, Tudor Ambarus - M18064 wrote:
> On 3/7/22 13:38, Eugen Hristev wrote:
>> Flexcom3 is used as board console serial. There are no pull-ups on these
>> lines on the board. This means that if a cable is not connected (that has
>> pull-ups included), stray characters could appear on the console as the
>> floating pins voltage levels are interpreted as incoming characters.
>> To avoid this problem, enable the internal pull-ups on these lines.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> 
> Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
and queued for "fixes". Thanks!
Best regards,
   Nicolas

> 
>> ---
>>   arch/arm/boot/dts/at91-sama7g5ek.dts | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
>> index 08685a10eda1d..dd047a8523907 100644
>> --- a/arch/arm/boot/dts/at91-sama7g5ek.dts
>> +++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
>> @@ -495,7 +495,7 @@ pinctrl_flx0_default: flx0_default {
>>   	pinctrl_flx3_default: flx3_default {
>>   		pinmux = <PIN_PD16__FLEXCOM3_IO0>,
>>   			 <PIN_PD17__FLEXCOM3_IO1>;
>> -		bias-disable;
>> +		bias-pull-up;
>>   	};
>>   
>>   	pinctrl_flx4_default: flx4_default {
> 


-- 
Nicolas Ferre