On Thu, Dec 21, 2023 at 10:39:06AM +0000, Andre Przywara wrote: > On Thu, 21 Dec 2023 10:20:49 +0800 > fuyao <fuyao@xxxxxxxxxx> wrote: > > Hi, > > thanks for the reply! > > > On Wed, Dec 20, 2023 at 03:04:00PM +0000, Andre Przywara wrote: > > > On Wed, 20 Dec 2023 16:18:43 +0800 > > > fuyao <fuyao1697@xxxxxxx> 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. > > Ah, thanks for the confirmation. > > > > > 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. > > Do you mean a USB *reference* voltage that is separate from the USB PHY > power supply voltage, so pin VCC-USB on the SoC? And that it is internally > connected to some TV-OUT related circuits? So that would apply to all > devices using the R40 SoC then? yes, The usb need a power from TV module insides. > > Or is it simply that the SoC pins VCC-TVOUT and VCC-USB are connected > together, on this SoM? no > Do you have access to some schematic? I couldn't find one online easily, > so cannot check this myself. > It has up to https://file.io/VSUL4FDrapDY > Thanks, > Andre > > > > > Signed-off-by: fuyao <fuyao1697@xxxxxxx> > > > > --- > > > > 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>; > > > > > -- fuyao [付尧]
