Re: Exynos850 and ExynosAuto v9 pinctrl wakeup muxed interrupt

[Sam Protsenko]

On Fri, 7 Jan 2022 at 10:16, Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxxxxx> wrote:
>
> On 03/01/2022 21:59, Sam Protsenko wrote:
> > On Thu, 30 Dec 2021 at 21:34, Krzysztof Kozlowski
> > <krzysztof.kozlowski@xxxxxxxxxxxxx> wrote:
> >>
> >> Hi Chanho and Sam,
> >>
> >> I am slowly finishing dtschema for Samsung pinctrl drivers [1] and I
> >> noticed that Exynos850 and Auto v9 do not define interrupt in pinctrl
> >> node with: wakeup-interrupt-controller. This is an interrupt muxing
> >> several external wakeup interrupts, e.g. EINT16 - EINT31.
> >>
> >> For Exynos5433 this looks like:
> >> https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/exynos/exynos5433.dtsi#L857
> >>
> >> Missing muxed interrupt for Exynos850 and Autov9 might be fine, although
> >> you should see in dmesg error log like:
> >>     "irq number for muxed EINTs not found"
> >>
> >> Can you check that your wakeup-interrupt-controller is properly defined
> >> in DTSI? If yes, I will need to include such differences in the dtschema.
> >>
> >
> > In case of Exynos850, no muxed interrupts exist for wakeup GPIO
> > domains. Basically, "pinctrl_alive" and "pinctrl_cmgp" domains are
> > wake-up capable, and they have dedicated interrupt for each particular
> > GPIO pin. All those interrupts are defined in exynos850-pinctrl.dtsi
> > file, in next nodes:
> >   - pinctrl_alive: gpa0..gpa4 (interrupt numbers 1..36)
> >   - pinctrl_cmgp: gpm0..gpm7 (interrupt numbers 39..46)
> >
> > All mentioned interrupts are wakeup interrupts, and there are no muxed
> > ones. So it seems like it's not possible to specify "interrupts"
> > property in pinctrl nodes with wakeup-interrupt-controller. The PM is
> > not enabled in Exynos850 platform yet, so I can't really test if
> > interrupts I mentioned are able to wake up the system.
>
> Thanks for confirming, I'll adjust the schema.
>
> >
> > After adding this patch ("arm64: dts: exynos: Add missing gpm6 and
> > gpm7 nodes to Exynos850"), I can't see this error message anymore:
> >
> >     samsung-pinctrl 11c30000.pinctrl: irq number for muxed EINTs not found
> >
> > That's because exynos_eint_wkup_init() function exits in this check:
> >
> >     if (!muxed_banks) {
> >         of_node_put(wkup_np);
> >         return 0;
> >     }
> >
> > But I actually can see another error message, printed in
> > exynos_eint_gpio_init() function (for wake-up capable pinctrl nodes,
> > because those nodes don't have "interrupts" property now -- you
> > removed those in your patch):
> >
> >     samsung-pinctrl 11850000.pinctrl: irq number not available
> >     samsung-pinctrl 11c30000.pinctrl: irq number not available
> >
> > which in turn leads to exynos_eint_gpio_init() function to exit with
> > -EINVAL code in the very beginning, and I'm not sure if it's ok? As I
> > said, those errors only appear after your patch ("arm64: dts: exynos:
> > drop incorrectly placed wakeup interrupts in Exynos850").
>
> Yeah, I replied to this next to my patch. I think my patch was not
> correct and you need one - exactly one - interrupt for regular GPIO
> interrupts.
>

I just need to remove ".eint_gpio_init" in exynos850_pin_ctrl[] for
pinctrl_alive and pinctrl_gpmc. Those already have ".eint_wkup_init",
which is enough to handle all interrupts (per-pin). GPIO_ALIVE and
GPIO_GPMC lack EINT capabilities: judging from TRM, there are no EINT
interrupts (like EINT_SVC, which is accessed in EINT ISR), and there
are no EINT interrupts wired to GIC (like INTREQ__GPIO_ALIVE or
INTREQ__GPIO_GPMC). With removed ".eint_gpio_init", I can see in
"/proc/interrupts" that corresponding interrupts are still handled
properly (because of .eint_wkup_init), and the error message is gone.
Will send the patch soon -- please add it to the beginning of your
series along with my other patch I already submitted.

> >
> > It raises next questions, which I'm trying to think over right now.
> > Krzysztof, please let me know if you already have answers to those:
> >
> > 1. Regarding "wakeup-interrupt-controller" node (and
> > exynos_eint_wkup_init() function): is it ok to not have "interrupts"
> > property in there? Would corresponding interrupts specified in child
> > nodes (gpa0..gpa4) function as wake-up interrupts in this case? Or
> > pinctrl driver should be reworked somehow?
>
> Yes, it should be fine. The message should be changed from error to info
> or even debug, maybe depending on SoC-type (so define in struct
> samsung_pin_ctrl whether exynos_eint_wkup_init expects muxed wake-ip
> interrupts).
>
> >
> > 2. Regarding missing interrupts in pinctrl nodes (and corresponding
> > error in exynos_eint_gpio_init() function): should it be reworked in
> > some way for Exynos850? Error message seems invalid in Exynos850 case,
> > and I'm not even sure if it's ok exynos_eint_gpio_init() fails. Should
> > it be modified to work that error around, in case of Exynos850?
> >
> > All other pinctrl nodes have a muxed interrupt (except pinctrl_aud,
> > but that's probably fine).
>
> The error message is valid - correctly points to wrong configuration.
> All pinctrl nodes should have one interrupt, if they have GPIOs capable
> of interrupt as a function (usually 0xf as GPIO CON register). Why
> pinctrl_aud does not have it? Maybe the function EXT_INT (0xf) is not
> available for its pins?
>
> Best regards,
> Krzysztof