Re: RFC: qcom spmi/ssbi-gpio hierarchical irqchip problems

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Tue, Dec 4, 2018 at 3:10 AM Brian Masney <masneyb@xxxxxxxxxxxxx> wrote:

> I started to work this evening on converting pinctrl-spmi-gpio.c to
> hierarchical irqs using pinctrl-stm32.c as a reference. I'll be
> able to test that this is working properly on the Nexus 5 by using
> gpio-keys with the volume up/down buttons on the phone. I'll need to
> remove the call to gpiod_to_irq() from gpio_keys.c in my local tree..

This is great news! Thank you so much for working on this!

> stm32_pctl_probe() only sets up the hierarchical irqs if
> interrupt-parent is defined on that node in device tree.

I don't know if that is strictly required. What device tree does
is just traverse upward to find the parent if no interrupt-parent
is defined, it will look for a parent in the parent node then
in the parent of the parent etc until it hits the default
interrupt controller in the root node.

> qcom-pm8941.dtsi currently doesn't have this property in the current
> mainline and it is also not present in the downstream Android sources
> for the Nexus 5. Does anyone know what I should put for the parent
> interrupt controller?

I'm a bit confused because the PM8xxx has its irqdomain
inside drivers/mfd/qcom-pm8xxx.c and the PM8941 driver
in drivers/mfd/qcom-spmi-pmic.c does not.

This on the PM8941 there appears to be no irqchip.
Then it falls upward to the spmi bus. This is
(qcom-msm8974.dtsi) an interrupt-controller with
four cells, so it should be:

interrupt-parent = <&spmi_bus>;

The irqchip and domain of the parent should be what
you find in drivers/spmi/spmi-pmic-arb.c

Yours,
Linus Walleij