Re: [PATCH 6/6] arm64: dts: imx8mm-kontron: Add support for reading SD_VSEL signal

From: Frieder Schrempf
Date: Mon Feb 13 2023 - 11:15:58 EST


On 13.02.23 17:08, Marek Vasut wrote:
> On 2/13/23 16:58, Frieder Schrempf wrote:
>> From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
>>
>> This fixes the LDO5 regulator handling of the pca9450 driver by
>> taking the status of the SD_VSEL into account to determine which
>> configuration register is used for the voltage setting.
>>
>> Even without this change there is no functional issue, as the code
>> for switching the voltage in sdhci.c currently switches both, the
>> VSELECT/SD_VSEL signal and the regulator voltage at the same time
>> and doesn't run into an invalid corner case.
>>
>> We should still make sure, that we always use the correct register
>> when controlling the regulator. At least in U-Boot this fixes an
>> actual bug where the wrong IO voltage is used.
>>
>> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
>
> I may have a kind-of obvious request, since we removed those SD_VSEL
> very recently from other boards, could you just revert all those patches
> and only fill in the SION bit in V2 on all those boards too ? That way,
> we fix the LDO5 regulator for everyone who used it before.

I thought about that, but as the SD_VSEL signal is controlling the LDO5,
I found it more useful/correct to have the sd-vsel-gpios property inside
the LDO5 regulator node. Therefore the old usage where sd-vsel-gpios was
inside the PMIC node isn't compatible anymore.