Re: [PATCH v6 2/3] ARM: dts: imx6qdl: Add Variscite VAR-SOM-MX6 SoM support

[James Hilliard]

On Fri, Jul 21, 2023 at 5:41 AM Francesco Dolcini <francesco@xxxxxxxxxx> wrote:
>
> On Fri, Jul 21, 2023 at 05:05:51AM -0600, James Hilliard wrote:
> > On Fri, Jul 21, 2023 at 4:43 AM Krzysztof Kozlowski
> > <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> > > On 21/07/2023 12:33, James Hilliard wrote:
> > > > +             compatible = "regulator-fixed";
> > > > +             regulator-name = "touch_3v3_supply";
> > > > +             regulator-always-on;
> > >
> > > Also, missing constraints.
> >
> > Hmm, what's the correct way to determine the constraint values?
>
> You should know/understand the hardware design. Normally when writing a
> DT file you have the hardware schematics and the relevant datasheets
> available.

I did find some datasheets/schematics, but I'm having trouble finding something
which indicates it would be anything other than 3.3v there(although I don't read
a lot of schematics in general so I might be missing something obvious):
https://www.variscite.com/wp-content/uploads/2017/12/VAR-SOM-MX6_v1-Datasheet.pdf
https://www.variscite.com/wp-content/uploads/2017/12/VAR-SOM-MX6_datasheet.pdf
https://www.variscite.com/wp-content/uploads/2017/12/VAR-MX6CustomBoard-Schematics-for-VAR-SOM-MX6_V1.pdf
https://www.variscite.com/wp-content/uploads/2017/12/V2_VAR-MX6CustomBoard-Schematics.pdf
https://www.variscite.com/wp-content/uploads/2017/12/VAR-MX6CustomBoard-Datasheet.pdf

>
> > I'm guessing they should just be set to this based on the name?:
> > regulator-min-microvolt = <3300000>;
> > regulator-max-microvolt = <3300000>;
>
> This looks like a good guess, assuming that the regulator name is
> correct.

Tested with that but it didn't work, screen failed so I guess must be
something different?

>
> Francesco
>