Re: [PATCH v2] arm64: dts: imx8mq-kontron-pitx-imx8m: remove vqmmc-supply node

[Michael Walle]

Hi Lucas,

Am 2021-09-14 10:20, schrieb Lucas Stach:
> Am Dienstag, dem 14.09.2021 um 09:26 +0200 schrieb Heiko Thiery:
> > The sw4 output (V_1V8_S0 voltage) from the PMIC is the main supply for
> > the 1V8 power domain. It is not only used as supply for the eMMC.
> > So this voltage can not be changed and is not allowed to switched off.
> > Therefore we do not want to provide this regulator to the SDHC driver 
> > to
> > control this voltage.
> This specific requirement should not be solved by removing the
> regulator connection from the SDHCI node, but instead by constraining
> the regulator voltage range to a fixed 3.3V and marking the regulator
> as always-on to reflect the hardware requirements in the DT.
>
> Also if your eMMC vqmmc is a fixed 3.3V, I don't think you need the
> faster pinctrl states, as you can't use the faster pin states anyways,
> as they require a 1.8V signaling voltage.

Are you speaking of the 1.8V signalling modes? As far as I know the
IMX SDHC controller will switch the voltage by its own function pin.
That is, its not a GPIO.

-michael