Re: [linux-sunxi] Re: [PATCH v4 07/10] dt-bindings: phy: add binding for Allwinner USB3 PHY

[Icenowy Zheng]

ä 2018å10æ18æ GMT+08:00 äå9:58:25, Rob Herring <robh@xxxxxxxxxx> åå:
>On Sat, Oct 13, 2018 at 9:42 PM Icenowy Zheng <icenowy@xxxxxxx> wrote:
>>
>> å 2018-10-05äç 15:58 -0500ïRob Herringåéï
>> > On Thu, Oct 04, 2018 at 08:28:52PM +0800, Icenowy Zheng wrote:
>> > > The new Allwinner H6 SoC contains a USB3 PHY that is wired to the
>> > > external USB3 pins of the SoC.
>> > >
>> > > Add a device tree binding for the PHY.
>> > >
>> > > Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
>> > > Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxx>
>> > > ---
>> > > Changes in v4:
>> > > - Changed Vbus regulator property to vbus-supply.
>> > >
>> > > Changes in v3:
>> > > - Added Chen-Yu's Review tag.
>> > >
>> > > No changes in v2, v1.
>> > >
>> > >  .../bindings/phy/sun50i-usb3-phy.txt          | 23
>> > > +++++++++++++++++++
>> > >  1 file changed, 23 insertions(+)
>> > >  create mode 100644 Documentation/devicetree/bindings/phy/sun50i-
>> > > usb3-phy.txt
>> > >
>> > > diff --git a/Documentation/devicetree/bindings/phy/sun50i-usb3-
>> > > phy.txt
>b/Documentation/devicetree/bindings/phy/sun50i-usb3-phy.txt
>> > > new file mode 100644
>> > > index 000000000000..9f49c6b8c7e7
>> > > --- /dev/null
>> > > +++ b/Documentation/devicetree/bindings/phy/sun50i-usb3-phy.txt
>> > > @@ -0,0 +1,23 @@
>> > > +Allwinner sun50i USB3 PHY
>> > > +-----------------------
>> > > +
>> > > +Required properties:
>> > > +- compatible : should be one of
>> > > +  * allwinner,sun60i-h6-usb3-phy
>> > > +- reg : a list of offset + length pairs
>> > > +- #phy-cells : from the generic phy bindings, must be 0
>> > > +- clocks : phandle + clock specifier for the phy clock
>> > > +- resets : phandle + reset specifier for the phy reset
>> > > +
>> > > +Optional Properties:
>> > > +- vbus-supply : a phandle to a regulator that provides power to
>> > > VBUS.
>> >
>> > This belongs in a connector node as it is part of the connector
>> > unless
>> > the phy physically needs Vbus for power.
>> >
>> > But others have done this, so all the phys can just be wrong...
>>
>> How should we reference the connector?
>>
>> Via OF graph or simply a property in PHY node?
>
>The connector is either a child of the controller or an OF graph from
>the controller to the connector. The phy driver needs the controller
>node and then it can walk the tree or graph to get the connector node.

Why is it a child of the controller?

I think on hardware the connector is connected to the PHY via USB, and PHY is
connected to the controller via ULPI/UTMI and PIPE, so the connector node
should link to PHY in some way, not to controller.

For Allwinner USB3 PHY I prefer to use child node now, as it's a simple
single-port PHY, and there seems to be no reserved space for multi-port.

>
>Rob