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

[Ahmad Fatoum]

Hello Marek,

On 10/15/20 2:52 PM, Marek Vasut wrote:
> On 10/15/20 2:44 PM, Ahmad Fatoum wrote:
> 
> Hi,
> 
> [...]
> 
>> 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:
> 
> You do need pullups on SD bus by default.

Yes, we are aware of this now :-)

> Currently the
> stm32mp15-pinmux.dtsi is not consistent in that aspect. I am not arguing
> about any one single board, but about the dtsi, I suspect by default the
> pull ups should be enabled, and possibly on board-DT-level they should
> be disabled if not needed instead ?

I think this is a good idea. But existing boards should be fixed up so that
their old behavior is maintained.

> [...]
> 
>> 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.)
> 
> I agree, the current state is just heading toward combinatorial
> explosion of pinmux entries.


Cheers
Ahmad

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