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    SubjectRe: [PATCH v4 3/4] dt-bindings: Add Qualcomm USB SuperSpeed PHY bindings
    On Thu 05 Sep 22:26 PDT 2019, Stephen Boyd wrote:

    > Quoting Jack Pham (2019-09-05 10:58:02)
    > > Hi Jorge, Bjorn,
    > >
    > > On Thu, Sep 05, 2019 at 09:18:57AM +0200, Jorge Ramirez wrote:
    > > > On 9/4/19 01:34, Bjorn Andersson wrote:
    > > > > On Tue 03 Sep 14:45 PDT 2019, Stephen Boyd wrote:
    > > > >> that would need an of_regulator_get() sort of API that can get the
    > > > >> regulator out of there? Or to make the connector into a struct device
    > > > >> that can get the regulator out per some generic connector driver and
    > > > >> then pass it through to the USB controller when it asks for it. Maybe
    > > > >> try to prototype that out?
    > > > >>
    > > > >
    > > > > The examples given in the DT bindings describes the connector as a child
    > > > > of a PMIC, with of_graph somehow tying it to the various inputs. But in
    > > > > these examples vbus is handled by implicitly inside the MFD, where
    > > > > extcon is informed about the plug event they toggle vbus as well.
    > > > >
    > > > > In our case we have a extcon-usb-gpio to detect mode, which per Jorge's
    > > > > proposal will trickle down to the PHY and become a regulator calls on
    > > > > either some external regulator or more typically one of the chargers in
    > > > > the system.
    > >
    > > Interesting you mention extcon-usb-gpio. I thought extcon at least from
    > > bindings perspective is passé now. Maybe this is what you need (just
    > > landed in usb-next):
    > >
    > > usb: common: add USB GPIO based connection detection driver
    > > https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=4602f3bff2669012c1147eecfe74c121765f5c56
    > >
    > > dt-bindings: usb: add binding for USB GPIO based connection detection driver
    > > https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=f651c73e71f53f65e9846677d79d8e120452b59f
    > >
    > > Fortunately this new driver might check the right boxes for you:
    > > - usb connector binding
    > > - ID detect GPIO
    > > - vbus-supply regulator
    > >
    > > With that, I think you can also keep the connector subnode out of the
    > > SSPHY node well, and similarly get rid of the vbus toggle handling from
    > > the PHY driver.
    > >
    > > The big thing missing now is that this driver replaces extcon
    > > completely, so we'll need handling in dwc3/dwc3-qcom to retrieve the
    > > role switch state to know when host mode is entered. I saw this a while
    > > back but don't think it got picked up:
    > >
    > > https://patchwork.kernel.org/patch/10909981/
    > >
    >
    > Yes this looks like the approach that should be taken. One question
    > though, is this a micro-b connector or a type-c connector on the board?
    > I thought it was a type-c, so then this USB gpio based connection driver
    > isn't an exact fit?
    >

    For this particular case it's a type c connector, but the port
    controller is operated completely passively (and there's no PD or DP
    involved), so the GPIO based approach seems like a good fit.

    Regards,
    Bjorn

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