Re: [PATCH] pinctrl: msm: Pass along set_wake failures

[Lina Iyer]

On Thu, Jul 12 2018 at 10:31 -0600, Evan Green wrote:
> On Tue, Jul 10, 2018 at 1:38 PM Lina Iyer <ilina@xxxxxxxxxxxxxx> wrote:
> > On Tue, Jul 10 2018 at 12:53 -0600, Evan Green wrote:
> > >On Mon, Jul 9, 2018 at 10:27 AM Bjorn Andersson
> > ><bjorn.andersson@xxxxxxxxxx> wrote:
> > >Our understanding is the downstream kernel had an interrupt hierarchy
> > >of GIC > PDC > TLMM & everybody else. In the downstream world PDC
> > >acted transparently, forwarding most requests directly onto the GIC,
> > >but quietly handling wake interrupts as well. With the upstream PDC
> > >driver, the #interrupt-cells got changed to 2, and it seemed like
> > >folks didn't like the idea that PDC was acting transparently. Correct
> > >me if I'm wrong there. So now we're sort of unsure about how to wire
> > >in PDC. If we make everybody an interrupt child of PDC, then we lose
> > >the ability to specify the third GIC parameter, and we're stuck
> > >expressing interrupts with respect to PDC pins, which is an awkward
> > >mental translation.
> > Its an unfortunate side effect of the design. Drivers will have to
> > request the PDC pin for wakeup IRQs.
>
> Would they use the PDC pin to request their regular interrupt, and the
> PDC would turn around and ask the GIC for them, and also enable the
> wakeup interrupt?>
Yes, drivers would need to request a PDC pin since using the
interrupts-extended format and then enable that interrupt was a wakeup
interrupt.

> Or would devices have some sort of separate entry for wakeup
> interrupts?
Not sure how you mean. If it's the DT you are asking, then yes, they
would need to have a separate entry in DT.

	wake-device {
       	interrupts-extended = <&pdc 2 IRQ_TYPE_LEVEL_HIGH>;
	};

See Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt

Thanks,
Lina