Messages in this thread | | | Date | Thu, 8 Feb 2024 10:18:12 +0530 | Subject | Re: [PATCH 2/3] arm64: dts: qcom: sa8295p: Enable tertiary controller and its 4 USB ports | From | Krishna Kurapati PSSNV <> |
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On 2/8/2024 10:11 AM, Dmitry Baryshkov wrote: > On Thu, 8 Feb 2024 at 04:40, Krishna Kurapati PSSNV > <quic_kriskura@quicinc.com> wrote: >> On 2/6/2024 6:54 PM, Dmitry Baryshkov wrote: >>> On Tue, 6 Feb 2024 at 14:28, Krishna Kurapati PSSNV >>> <quic_kriskura@quicinc.com> wrote: >>>> >>>> >>>> >>>> On 2/6/2024 5:43 PM, Dmitry Baryshkov wrote: >>>>> On Tue, 6 Feb 2024 at 14:03, Krishna Kurapati <quic_kriskura@quicinc.com> wrote: >>>>>> >>>>>> Enable tertiary controller for SA8295P (based on SC8280XP). >>>>>> Add pinctrl support for usb ports to provide VBUS to connected peripherals. >>>>> >>>>> These are not just pinctrl entries. They hide VBUS regulators. Please >>>>> implement them properly as corresponding vbus regulators. >>>>> >>>> >>>> Hi Dmitry. Apologies, can you elaborate on your comment. I thought this >>>> implementation was fine as Konrad reviewed it in v13 [1]. I removed his >>>> RB tag as I made one change of dropping "_state" in labels. >>> >>> My comment is pretty simple: if I'm not mistaken, your DT doesn't >>> reflect your hardware design. >>> You have actual VBUS regulators driven by these GPIO pins. Is this correct? >>> If so, you should describe them properly in the device tree rather >>> than describing them just as USB host's pinctrl state. >>> >> >> Hi Dmitry, >> >> I have very little idea about the gpio controller regulators. I will >> go through it and see how I can implement it. I just found this : >> https://www.kernel.org/doc/Documentation/devicetree/bindings/regulator/gpio-regulator.txt > > Much simpler, it can be found at > Documentation/devicetree/bindings/regulator/fixed-regulator.yaml
Thanks for the reference.
> >> One query. If we model it as a regulator, do we need to add it as a >> supply and call regulator_enable in dwc3_qcom probe again ? > > Not in probe(), but yes. It needs to be enabled when the VBUS has to > be powered up, when the device is initialised or switched to the host > mode, and disabled when the VBUS has to be powered down, if the device > is being switched to the device mode. >
Actually since we never go to device mode, can't we just stick to this pinctrl approach and skip turning on regulator in driver ?
Regards, Krishna,
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