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

chunfeng yun
2015-08-01T03:42:18Z

hi,
On Fri, 2015-07-31 at 14:37 +0100, Mark Rutland wrote:
> 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.
>
Is it ok to add a prefix of syscon, and name it syscon-usb-wakeup?

> >
> > > > + - 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?
>
It is unthoughtful to put it here;
There is different configuration on platforms, such as on tablet which
only needs line-state wakeup (because system can't enter suspend when
plug in usb cable, so don't need ip-sleep-wakeup to remote wakeup
system), and on box just needs ip-sleep wakeup mode. so it is better to
put in each board's dts.

> >
> > > > + - 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.
>
Yes, you are right.
This confuse me a little before. It was a property of old phy driver at
first, and then ported it here, so did not remove it temp.
After I re-write the phy driver, I will remove it.

Thanks a lot.

> Thanks,
> Mark.