Re: [PATCH v3 2/5] dt-bindings: Add a binding for Mediatek xHCI host controller

Mark Rutland
2015-07-31T13:37:41Z

Hi,

> > > + - mediatek,usb-wakeup: to access usb wakeup control register
> >
> > What exactly does this property imply?
> >
> There are some control registers for usb wakeup which are put in another
> module, here to get the node of that module, and then use regmap and
> syscon to operate it.

Ok. You need to specify the type of this property (i.e. that it is a
phandle to a syscon node). The description makes it sound like a boolean.

>
> > > + - mediatek,wakeup-src: 1: ip sleep wakeup mode; 2: line state wakeup
> > > + mode; others means don't enable wakeup source of usb
> >
> > This sounds like configuration rather than a hardware property. Why do
> > you think this needs to be in the DT?
> >
> Yes, it's better to put it in the DT.

That doesn't answer my question.

_why_ do you think this needs to be in the DT? What do you think is
better for it being there?

>
> > > + - mediatek,u2port-num: the number should not greater than the number
> > > + of phys
> >
> > What exactly does this property imply?
> >
> On some platform, it only makes use of partial usb ports, so disable
> others to save power.

What exactly do you mean by "partial USB ports"?

If a phy isn't wired up, it won't be listed in the phys property, if it
is then disabling it sounds like a run-time decision.

Thanks,
Mark.