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

[Lina Iyer]

On Wed, Nov 21 2018 at 14:36 -0700, Stephen Boyd wrote:
> Quoting Lina Iyer (2018-11-20 16:06:47)
> > SDM845 SoC has an always-on interrupt controller (PDC) with select GPIO
> > routed to the PDC as interrupts that can be used to wake the system up
> > from deep low power modes and suspend.
> >
> > Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> > ---
> >  .../bindings/pinctrl/qcom,sdm845-pinctrl.txt  | 31 ++++++++++++++++++-
> >  1 file changed, 30 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pinctrl/qcom,sdm845-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/qcom,sdm845-pinctrl.txt
> > index 665aadb5ea28..bedfa0b57fa6 100644
> > --- a/Documentation/devicetree/bindings/pinctrl/qcom,sdm845-pinctrl.txt
> > +++ b/Documentation/devicetree/bindings/pinctrl/qcom,sdm845-pinctrl.txt
> > @@ -29,6 +29,17 @@ SDM845 platform.
> >         Definition: must be 2. Specifying the pin number and flags, as defined
> >                     in <dt-bindings/interrupt-controller/irq.h>
> >
> > +- wakeup-parent:
> > +       Usage: optional
> > +       Value type: <phandle>
> > +       Definition: A phandle to the wakeup interrupt controller for the SoC.
> > +
> > +- wakeup-irq:
>
> This shouldn't be needed. TLMM driver can probe for the possibility of
> wakeup capable irqs from irq allocation step. The only place we should
> need to know what TLMM pins map to what PDC lines is in the PDC driver.
Why? Every driver seems to translate the hardware IRQ and pass it to
it's parent. Why should this be any different ? The PDC is an interrupt
controller that just knows an interrupt port and maps it to the GIC. Not
sure, I understand the reasoning for this. It seems to add more
confusing relationship with the PDC interrupt controller, that way.

-- Lina