[Linux-stm32] [PATCH] ARM: dts: stm32: Consistently enable internal pull-ups for SD bus

Ahmad Fatoum a.fatoum at pengutronix.de
Thu Oct 15 08:44:29 EDT 2020


Hello Yann,

thanks for pinging me.

On 10/14/20 3:26 PM, Yann GAUTIER wrote:
> On 10/9/20 11:08 PM, Marek Vasut wrote:
>> @@ -1510,7 +1510,7 @@ pins {
>>   				 <STM32_PINMUX('C', 7, AF10)>; /* SDMMC2_D7 */
>>   			slew-rate = <1>;
>>   			drive-push-pull;
>> -			bias-disable;
>> +			bias-pull-up;
> This one is also used on Linux Automation MC-1 board, Ahmad, is it OK 
> for you?

Hello Marek,

We already have 47K external pull-ups on all the SDMMC2's data lanes and we
don't need the SoC-internal pull-up there as well.

On the SDMMC1 we lack them, so they were added in the board DTS:

  /* stm32mp157c-lxa-mc1.dts */
  &sdmmc1_b4_pins_a {
          /*
           * board lacks external pull-ups on SDMMC lines. Class 10 SD refuses to
           * work, thus enable internal pull-ups.
           */
          pins1 {
                  /delete-property/ bias-disable;
                  bias-pull-up;
          };
          pins2 {
                  /delete-property/ bias-disable;
                  bias-pull-up;
          };
  };

I don't mind the central pinctrl settings changed to make them more widely applicable
if current users get such override nodes inserted to maintain their existing settings.

(My favorite would of course be to allow board DTS to just keep their own pinctrl
 nodes outside stm32mp15-pinctrl.dtsi.)

Cheers
Ahmad
 


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