RE: [PATCH v3 01/12] dt-bindings: clock: renesas,r9a08g045-vbattb: Document VBATTB

Biju Das
2024-09-03T07:29:33Z

Hi Geert,

> -----Original Message-----
> From: Biju Das <biju.das.jz@bp.renesas.com>
> Sent: Tuesday, September 3, 2024 8:25 AM
> Subject: RE: [PATCH v3 01/12] dt-bindings: clock: renesas,r9a08g045-vbattb: Document VBATTB
>
> Hi Geert,
>
> > -----Original Message-----
> > From: Geert Uytterhoeven <geert@linux-m68k.org>
> > Sent: Tuesday, September 3, 2024 8:23 AM
> > Subject: Re: [PATCH v3 01/12] dt-bindings: clock:
> > renesas,r9a08g045-vbattb: Document VBATTB
> >
> > Hi Biju,
> >
> > On Tue, Sep 3, 2024 at 8:58 AM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> > > > -----Original Message-----
> > > > From: Claudiu <claudiu.beznea@tuxon.dev>
> > > > Sent: Friday, August 30, 2024 2:02 PM
> > > > Subject: [PATCH v3 01/12] dt-bindings: clock:
> > > > renesas,r9a08g045-vbattb: Document VBATTB
> > > >
> > > > From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> > > >
> > > > The VBATTB IP of the Renesas RZ/G3S SoC controls the clock for
> > > > RTC, the tamper detector and a small general usage memory of 128B. Add documentation for it.
> > > >
> > > > Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> >
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/clock/renesas,r9a08g045-vb
> > > > +++ at
> > > > +++ tb.yaml
> > > > + power-domains:
> > > > + maxItems: 1
> > >
> > > Not sure, you need to document "PD_VBATT" power domain as per Table
> > > 41.2, this LSI supports 3 power domains(PD_ISOVCC, PD_VCC, PD_VBATT)
> > >
> > > Power Mode PD_ISOVCC PD_VCC PD_VBATT
> > > ALL_ON ON ON ON
> > > AWO OFF ON ON
> > > VBATT OFF OFF ON
> > > ALL_OFF OFF OFF OFF
> > >
> > > PD_VBATT domain is the area where the RTC/backup register is
> > > located, works on battery power when the power of PD_VCC and PD_ISOVCC domain are turned off.
> >
> > AFAIU, PD_VBATT cannot be controlled by the user, and is just on if main or battery power is
> supplied.

As per Figure 41.1 Power Domain and Power Supply,

If both PMIC PWS off, PD_VBATT is active, so looks like it is controllable
Outside Linux.

Cheers,
Biju