Re: [PATCH v4 3/3] arm64: dts: imx95: Add support for Data Modul i.MX95 eDM SBC

[Frank Li <Frank.li@oss.nxp.com>]

On Mon, Sep 21, 2026 at 08:43:35PM +0200, Marek Vasut wrote:
> On 9/21/26 7:11 PM, Frank Li wrote:
>
> Hello Frank,
>
> > > > > > But why DTO need update regulator-panel-vcc's gpio informaiton. I suppose
> > > > > > it is fixed when board design.
> > > > >
> > > > > It is just a GPIO, it can have either polarity depending on the regulator
> > > > > that it controls.
> > > >
> > > > Understand, But the problem is why polarity change after board design?
> > > >
> > > > If reg_panel_vcc is on added on boards,  should it be in dtso file also to
> > > > match your hardware design correctly?
> > >
> > > We want to avoid duplication in the DTOs files, do we not ?
> >
> > Yes, but there are not dtso file yet, I don't know how to share it yet.
>
> Yes, there is no DTSO, because there is no DPU support for MX95, so display
> support in upstream is missing (check with Victor Liu, they might know more
> about the current state).
>
> > > Hence, base common stuff in the base DT, stuff that changes in the DTOs.
> >
> > Idea is good, but avoid hack stuff. Can you show me what's plan use
> > reg_panel_vcc in dtso and how to share it.
> See above, currently I cannot really use the regulator, because of the
> missing DPU support.

I suggest add it when it will be used.  Or Remove gpios = <&i2c2_gpio_expander_20 17 0>;

Suppose it will be overwrited by dtso future.

> The only DTO I temporarily have in tree (used with my
> DPU patchset) is for the RPi 7" display 2, which does not use this
> regulator.
>
> The plan is to use it the same way as on the MX8MM/MX8MP eDM SBC in the DTO:
>
> &reg_panel_vcc {
>   gpios = <&i2c2_gpio_expander_20 17 GPIO_ACTIVE_HIGH>;
>   enable-active-high;
>   status = "okay";
> };
>
> or
>
> &reg_panel_vcc {
>   gpios = <&i2c2_gpio_expander_20 17 GPIO_ACTIVE_LOW>;
>   status = "okay";
> };

In future, it should be nexus node for it and put reg_panel_vcc into dtso
files, and looks like you use gpio controller add-on boards's regulator.

Frank