Re: [RFC v3 2/3] dt-bindings: sdm845-pinctrl: add wakeup interrupt parent for GPIO

[Lina Iyer]

On Tue, Nov 27 2018 at 14:45 -0700, Stephen Boyd wrote:
> Quoting Lina Iyer (2018-11-27 10:21:23)
> > On Tue, Nov 27 2018 at 02:12 -0700, Stephen Boyd wrote:
> > >
> > >Two reasons. First, simplicity. The TLMM driver just needs to pass the
> > >gpio number up to the PDC gpio domain and then that domain can figure
> > >out what hwirq it maps to within the PDC hw irq space. I don't see any
> > >reason why we have to know the hwirq of PDC within the TLMM driver
> > >besides "let's not be different".
> > >
> > >And second, it makes it easier for us to implement the MPM case in the
> > >TLMM driver by letting the TLMM code just ask "should I mask the irq
> > >here or not?" by passing that with a wrapper struct around the fwspec
> > >and a dedicated domain in the PDC/MPM driver. Keeping less things in the
> > >TLMM driver and not driving the decision from DT but from tables in the
> > >PDC driver also keeps things simple and reduces DT parsing code/time.
> > >
> > Couldn't this be simply achieved by matching the compatible flags for
> > PDC/MPM bindings for the wakeup-parent in the TLMM driver?
>
> It could be, but then we would be making TLMM highly aware of the wakeup
> parent
It is is not aware of anything about the wakeup parent, just the
compatible that indicates whether it needs to be mask locally or not.

> and have to do compatible string matching in two places, instead
> of making TLMM more abstractly aware that it needs to keep things masked
> while irq parent deals with the interrupts.
Your approach seems too complex just to circumvent a simple match node.
I think we are stretching too much to support something that is not a
priority.

-- Lina