Re: [PATCH v6 1/3] dt-bindings: Add beaglecc1352

From: Nishanth Menon
Date: Tue Oct 03 2023 - 09:06:21 EST


On 18:17-20231003, Ayush Singh wrote:
> > > +
> > > + reset-gpios:
> > > + maxItems: 1
> > > +
> > > + power-gpios:
> > > + maxItems: 3
> > > + description:
> > > + The device has three power rails that are exposed on external pins VDDS,
> > > + VDDR and DCOUPL.
> > Shouldn't these be regulators? The power rails are input to the MCU,
> > correct?
> > The properties should be something like:
> > vdds-supply
> > vddr-supply
> > dcoupl-supply ? (not sure what dcoupl is, but description should provide
> > that info).
> >
> > the gpio controls for those can be modelled by regulator-gpio ?
>
> I picked up power lines from "CC13xx/CC26xx Hardware Configuration and PCB
> Design Considerations Application Report" present under "8.14 Network
> Processor" of CC1352P7 data sheet.
>
> But now looking closer, it doesn't seem like DCOUPL can be supplied
> externally for CC1352P7 and thus should probably be removed.
>
> Also, it seems like for CC1352P7, VDDR must always be supplied internally
> (The data sheet states: "Internal supply, must be powered from the internal
> DC/DC converter or the internal LDO"). Thus, it should be safe to remove
> VDDR as well.
>From Figure 3-1. CC1312R 7x7 RF Part Schematic Overview (app report you
point out below)
Typical usage is vdds-supply supplying:
VDDS (pin 44)
VDDS2 (pin 13)
VDDS3 (pin 22)
VDDS_DCDC (pin 34)

And DCDC_SW (pin 33) supplies vddr supplying:
VDDR(pin 45)
VDDR_RF (Pin 48)

>
>
> That means only VDDS needs to be present for power line.

I agree that that would be the typical supply model. So, just
vdds-supply

>
>
> CC13xx/CC26xx Hardware Configuration and PCB Design Considerations
> Application Report: https://www.ti.com/lit/pdf/swra640
>
> CC1352P7 Data sheet: https://www.ti.com/lit/gpn/CC1352P7

--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D