Re: [RFC PATCH v2 1/3] usb: dwc3: msm: Add device tree bindinginformation

From: Ivan T. Ivanov
Date: Wed Aug 14 2013 - 03:19:52 EST


Hi,

On Tue, 2013-08-13 at 13:57 -0600, Stephen Warren wrote:
> On 08/09/2013 03:53 AM, Ivan T. Ivanov wrote:
> > From: "Ivan T. Ivanov" <iivanov@xxxxxxxxxx>
> >
> > MSM USB3.0 core wrapper consist of USB3.0 IP (SNPS)
> > and HS, SS PHY's controll and configuration registers.
>
> s/controll/control/
>

Thanks.

> > It could operate in device mode (SS, HS, FS) and host
> > mode (SS, HS, FS, LS).
>
> > diff --git a/Documentation/devicetree/bindings/usb/msm-ssusb.txt b/Documentation/devicetree/bindings/usb/msm-ssusb.txt
>
> > +MSM SuperSpeed DWC3 USB SoC controller
> > +
> > +Required properities :
> > +- compatible : sould be "qcom,dwc3-hsphy";
> ...
> > +Required properities :
> > +- compatible : sould be "qcom,dwc3-ssphy";
>
> I would expect different compatible values to be documented in different
> files.

It is easy to see connection between them when they are in
one file. Drivers are useless without each other.

>
> > +Optional properties :
> > +- gdsc-supply : phandle to the globally distributed switch controller
> > + regulator node to the USB controller.
>
> Which of the 3 compatible values that were described above is that
> property optional for?

"qcom,dwc3". I will make this more explicit.

>
> > +Sub nodes:
> > +- Sub node for "DWC3 USB3 controller".
> > + This sub node is required property for device node. The properties
> > + of this subnode are specified in dwc3.txt.
>
> Why not represent the PHY and USB controller as separate top-level
> nodes? They can point at each-other with phandles if they need to know
> each-others' identity.

"qcom,dwc3" (glue layer) driver have to be loaded before "snps,dwc3",
actual USB3 IP. "qcom,dwc3" provide required clocks and power supplies
to the USB3 IP core.

Regards,
Ivan


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