[PATCH] ARM: tegra: beaver: allow SD card voltage to be changed

Jon Hunter jonathanh at nvidia.com
Fri Jun 24 02:14:27 PDT 2016


Hi Adrian,

On 14/06/16 15:19, Jon Hunter wrote:

...

>>> So the controller itself supports UHS-I modes, but a given board may not
>>> have the regulator to support them. We need a way to determine if the
>>> board can support the UHS-I modes. Now we could check to see if the
>>> regulator is present in the Tegra SDHCI driver and if not remove the cap
>>> flags. However, I was not sure if this is applicable to other sdhci
>>> controllers and so there should be a generic solution for this?
>>
>> There is SDHCI_QUIRK2_NO_1_8_V but it doesn't cover the eMMC 1.8V DDR52 case
>> at present.  Dong Aisheng wanted to plug that gap but I wanted to get rid of
>> SDHCI_QUIRK2_NO_1_8_V:
>>
>> 	http://marc.info/?l=linux-mmc&m=146132847206423&w=2
> 
> Ok, that would require the tegra sdhci driver to set this quirk for a
> board, which is do-able, I guess. However, given the above I am not sure
> what path you are suggesting we take to resolve this? Does not sound
> like we should be looking at using SDHCI_QUIRK2_NO_1_8_V anyway.

Any feedback here? Are you still planning to get rid of
SDHCI_QUIRK2_NO_1_8_V or should we use this?

Cheers
Jon

-- 
nvpublic



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