Hi, On Mon, Apr 25, 2022 at 2:14 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote: > > Quoting Douglas Anderson (2022-04-25 14:06:42) > > We're supposed to list the supplies in the dt bindings but there are > > none in the DP controller bindings. Looking at the Linux driver and > > existing device trees, we can see that two supplies are expected: > > - vdda-0p9-supply > > - vdda-1p2-supply > > > > Let's list them both in the bindings. Note that the datasheet for > > sc7280 doesn't describe these supplies very verbosely. For the 0p9 > > supply, for instance, it says "Power for eDP 0.9 V circuits". This > > this is obvious from the property name, we don't bother cluttering the > > bindings with a description. > > > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > > --- > > > > .../devicetree/bindings/display/msm/dp-controller.yaml | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/msm/dp-controller.yaml b/Documentation/devicetree/bindings/display/msm/dp-controller.yaml > > index cd05cfd76536..dba31108db51 100644 > > --- a/Documentation/devicetree/bindings/display/msm/dp-controller.yaml > > +++ b/Documentation/devicetree/bindings/display/msm/dp-controller.yaml > > @@ -76,6 +76,9 @@ properties: > > "#sound-dai-cells": > > const: 0 > > > > + vdda-0p9-supply: true > > + vdda-1p2-supply: true > > + > > ports: > > $ref: /schemas/graph.yaml#/properties/ports > > properties: > > @@ -137,6 +140,9 @@ examples: > > > > power-domains = <&rpmhpd SC7180_CX>; > > > > + vdda-0p9-supply = <&vdda_usb_ss_dp_core>; > > Having 'a' in 'vdda' typically means 'analog' for 'analog' circuits, so > I'd expect this to only matter for the phy that contains the analog > circuitry. It would be great to remove the regulator code from > drivers/gpu/drm/msm/dp/dp_power.c and move the regulator_set_load() call > to the phy driver if possible. Hopefully qcom folks can help clarify > here. Interesting. Oddly enough, the sc7280 datasheet doesn't list the "_A". It calls these "VDD_VREF_0P9" and "VDD_VREF_1P2". However, on the schematic in front of me someone labeled these pins on the sc7280 with the "A". ...and the driver looks for a supply with the "a". :-/ It would be good to get clarification from someone with better information. -Doug
