Re: [PATCH 3/7] pinctrl: renesas: rzt2h: setup IRQ in .irq_{request,release}_resources()

[Geert Uytterhoeven]

Hi Cosmin,

On Mon, 17 Aug 2026 at 20:58, Cosmin Tanislav
<cosmin-gabriel.tanislav.xa@xxxxxxxxxxx> wrote:
> When exporting a GPIO using the deprecated sysfs GPIO API,
> gpio_is_visible() calls gpiod_to_irq() to determine whether a GPIO is
> IRQ-capable, which ends up using
> struct gpio_irq_chip::child_to_parent_hwirq().
>
> When using the GPIO character device, it is possible to request a line
> and to dynamically switch between using it as an IRQ or as a GPIO, by
> updating the edge detector.
>
> The current struct gpio_irq_chip::child_to_parent_hwirq() implementation
> makes the assumption that it will only be called with the intention of
> setting up the IRQ permanently, and that it will only be released when
> the IRQ domain is freed.
>
> Since we now know that this is not the case, take the following steps in
> order to properly handle that case.
>
> Implement struct irq_chip::irq_{request,release}_resources() based on
> the default GPIOCHIP_IRQ_RESOURCE_HELPERS implementations.
>
> Move the IRQ setup and release logic inside them.
>
> Keep the mapping logic inside ::child_to_parent_hwirq() to be able to
> provide a proper HW IRQ number, but do not actually setup the IRQ.
>
> Remove rzt2h_gpio_irq_domain_free() as its only purpose was to free
> the acquired IRQs.
>
> Cc: stable@xxxxxxxxxx
> Fixes: 829dde3369a9 ("pinctrl: renesas: rzt2h: Add GPIO IRQ chip to handle interrupts")
> Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@xxxxxxxxxxx>

Thanks for your patch!

> --- a/drivers/pinctrl/renesas/pinctrl-rzt2h.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzt2h.c
> @@ -1062,18 +1047,21 @@ static int rzt2h_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
>
>         rzt2h_pinctrl_set_pfc_mode(pctrl, port, pin, PFC_FUNC_INTERRUPT);
>
> -       *parent = parent_irq;
> -       *parent_type = child_type;
> +       ret = gpiochip_lock_as_irq(gc, hwirq);
> +       if (ret) {
> +               clear_bit(parent_irq - RZT2H_INTERRUPTS_START, pctrl->used_irqs);

irq_idx

> +               rzt2h_pin_write_pm(pctrl, port, pin, pctrl->saved_pm[irq_idx]);
> +               rzt2h_pinctrl_set_gpio_en(pctrl, port, pin, true);
> +               return ret;
> +       }
>
>         return 0;
>  }
>
> -static void rzt2h_gpio_irq_domain_free(struct irq_domain *domain, unsigned int virq,
> -                                      unsigned int nr_irqs)
> +static void rzt2h_gpio_irq_release_resources(struct irq_data *d)
>  {
> -       struct irq_data *d = irq_domain_get_irq_data(domain, virq);
>         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> -       struct rzt2h_pinctrl *pctrl = container_of(gc, struct rzt2h_pinctrl, gpio_chip);
> +       struct rzt2h_pinctrl *pctrl = gpiochip_get_data(gc);
>         irq_hw_number_t hwirq = irqd_to_hwirq(d);
>         u8 port = RZT2H_PIN_ID_TO_PORT(hwirq);
>         u8 pin = RZT2H_PIN_ID_TO_PIN(hwirq);
> @@ -1089,7 +1077,39 @@ static void rzt2h_gpio_irq_domain_free(struct irq_domain *domain, unsigned int v
>                 rzt2h_pinctrl_set_gpio_en(pctrl, port, pin, true);
>         }
>
> -       irq_domain_free_irqs_common(domain, virq, nr_irqs);

Why is this no longer needed?

> +       gpiochip_unlock_as_irq(gc, hwirq);
> +}

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds