Messages in this thread Patch in this message | | | Date | Thu, 21 Dec 2023 10:20:49 +0800 | From | fuyao <> | Subject | Re: [PATCH RESEND] ARM: dts: sun8i: r40: open the regulator aldo1 |
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On Wed, Dec 20, 2023 at 03:04:00PM +0000, Andre Przywara wrote: > On Wed, 20 Dec 2023 16:18:43 +0800 > fuyao <fuyao1697@cyg.com> wrote: > > Hi, > > > the aldo1 is connect regulator pin which power the TV. > > What do you mean with that? That ALDO1 is connected to VCC-TVOUT and/or > VCC-TVIN on the R40 SoC?
The ALDO1 is connected to VCC-TVOUT on the R40 Soc.
> > > The USB core use TV ref as reference Voltage. > > The USB core in the SoC? So pin VCC-USB, which requires 3.3V, the same > voltage as the TV pins? > Which means this doesn't really have much to do with TV, it's just that > USB and also "TV" are supplied by ALDO1?
The internal USB PHY requires a reference voltage. It seems that in order to save costs, the reference voltage of the TVOUT module is used.
> > > Signed-off-by: fuyao <fuyao1697@cyg.com> > > --- > > arch/arm/boot/dts/allwinner/sun8i-r40-feta40i.dtsi | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/arch/arm/boot/dts/allwinner/sun8i-r40-feta40i.dtsi b/arch/arm/boot/dts/allwinner/sun8i-r40-feta40i.dtsi > > index 9f39b5a2bb35..8906170461df 100644 > > --- a/arch/arm/boot/dts/allwinner/sun8i-r40-feta40i.dtsi > > +++ b/arch/arm/boot/dts/allwinner/sun8i-r40-feta40i.dtsi > > @@ -42,6 +42,13 @@ &pio { > > vcc-pg-supply = <®_dldo1>; > > }; > > > > +®_aldo1 { > > + regulator-always-on; > > So did USB never work before, with the DT as in mainline? >
The USB can work, but is unstable. Occasionally disconnected because of the D+/D- electrical characteristics.
> For always-on regulators it would be good to see some rationale why this > cannot be referenced by its consumer. If it is really supplying the USB > core, that would be a reason, because we don't have a good way of > describing this. > > > + regulator-min-microvolt = <3300000>; > > + regulator-max-microvolt = <3300000>; > > + regulator-name = "vcc-aldo1"; > > Regulators should be named after their users, so use something like: > regulator-name = "vcc-3v3-tv-usb"; >
thanks.
> That then also serves as documentation of why this is always on. > > Cheers, > Andre > > > +}; > > + > > ®_aldo2 { > > regulator-always-on; > > regulator-min-microvolt = <1800000>; >
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