On Thu, 18 Jun 2015 16:47:48 +0800
Li Jun <b47624@xxxxxxxxxxxxx> wrote:
> On Thu, Jun 18, 2015 at 10:36:50AM +0300, Roger Quadros wrote:
> > Lin,
> >
> > You can use --in-reply-to "message id of v5 of this path" so that it appears together
> > with the other patches in peoples mailboxes.
> >
> > > + * the passed properties in DT.
> > > + * @np: Pointer to the given device_node
> > > + * @otg_caps: Pointer to the target usb_otg_caps to be set
> > > + *
> > > + * The function gets and sets the otg capabilities
> > > + */
> > > +void of_usb_set_otg_caps(struct device_node *np, struct usb_otg_caps *otg_caps)
> > > +{
> > > + u32 otg_rev;
> > > +
> > > + if (!otg_caps)
> > > + return;
> > > +
> > > + if (!of_property_read_u32(np, "otg-rev", &otg_rev))
> > > + otg_caps->otg_rev = otg_rev;
> >
> > should we check if otg_rev is in correct format?
> > anything non BCD and greater than 0x9999 is invalid.
> >
> > Also if otg-rev is not passed then we need to treat it as legacy
> > platform right? How is this taken care of?
> >
> Missed this comment
> This handling rely on controller driver, cannot decided here.
> There are several cases we need take care:
> 1) otg-rev is not passed, but all 3 disable flags passed, this is
> valid, means user want to disable whole OTG, so only "otg-rev"
> not passed, cannot treat as legacy platform.
> 2) Legacy platform means: none of 4 properties is present.
Right. Plus controller drivers that are not updated to use these otg_caps
are also legacy.
> 3) Some controller drivers already support OTG HNP/SRP, then change
> to utilize those new flags, still should support OTG HNP/SRP w/o
> any dt change, so OTG caps should be enabled for legacy platforms.
I didn't understand this point. If a controller driver is not updated
to use otg_caps it is legacy and gadget->otg_caps will be NULL.
> 4) Some controller drivers does not support any OTG, after add OTG
> functions and utilize those new flags, should keep OTG disabled
> for legacy platforms.
If controller drivers don't support OTG. gadget->is_otg and
gadget->otg_caps will not be set by them and they don't have to use
of_usb_set_otg_caps().
So I didn't understand why the decision can't be taken here
for non-legacy controller drivers with legacy DT.
They will set gadget->otg_caps and gadget->is_otg.
If none of the 4 DT flags are passed then we know it is legacy DT
and we can limit to legacy behaviour.
cheers,
-roger
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