Re: [PATCH] of/platform: Allow secondary compatible match in of_dev_lookup

From: Tony Lindgren
Date: Tue Apr 12 2016 - 11:13:36 EST


* Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> [160407 04:19]:
> Grygorii Strashko <grygorii.strashko@xxxxxx> writes:
> > Most probably this is required to pass some data from parent device to
> > children when parent dev instantiate children from DT, at least I've experimented with
> > this in mostly similar way (I've not added second pass and did break in the first
> > if !phys_addr, but Tony's patch is more correct).

OK that's a different use case I have, but good to know it helps
with that too.

> > For example,
> > - USB dwc3 platform/integration layer dev creates DWC3-core device (of_platform_populate())
> > - DWC3-core device creates xhci device
> > - USB dwc3 platform/integration layer dev can dynamically get rev info
> > from HW and identify limitation/erratas/quirks which need to be applied to
> > to its children.
> > - DWC3-core can dynamically get rev info ...
> >
> > I was not able to find any other proper way to pass this (platfrom)data to children, except
> > using Auxdata. And, as per Felipe Balbi, It was the major reason why now
> > DWC3-core device creates xhci device manually.
>
> doesn't device_property() solve that ? I'm just waiting for some patches
> from Heikki (in Cc) before we rip pdata from dwc3 completely. At that
> point, we can look at building xhci from DT.
>
> The only thing that comes to mind is how this will look for PCI-only
> systems if we rip manual xHCI device creation completely.

Sounds like this dwc3 thread is a bit separate from the $subject patch
except for the legacy usage.

Regards,

Tony