Hi Doug, >> >> 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.ya >> > +++ ml >> > @@ -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 Our internal power grid documents list the regulators as VDD_A_*_1P2 and VDD_A_*_0P9 for all the platforms. So, as a practice, we put the same name in the DT files. Hence, Reviewed-by: Sankeerth Billakanti <quic_sbillaka@xxxxxxxxxxx> Thank you, Sankeerth
