On Thu, Jun 18, 2015 at 03:07:48PM +0300, Roger Quadros wrote:
> 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.
>
Did not understand the "Plus" case.
Some of 4 properties is present, but its driver dose not use otg_caps?
> > 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.
>
Some of existing chipdea platforms work fine on HNP and SRP , which did
not use any new flags and properties, after my patch, those platform should
still enable HNP and SRP without any DT change.
> > 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().
>
But after my patch, some time later, this driver adds OTG functions on
it new platform, it should disable any OTG feature for its legacy
platforms (none of properties is passed).
> 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.
>
legacy behaviour number is 2, not only one legacy behaviour.
That's why I leave the otg caps decided by controller drivers.
> cheers,
> -roger
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