Re: [PATCH v3 4/5] gpio: gpiolib: Add ngirq member to struct gpio_irq_chip

Lad, Prabhakar
2022-05-18T18:30:37Z

Hi Geert,

Thank you for the review.

On Thu, May 12, 2022 at 8:29 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Prabhakar,
>
> On Wed, May 11, 2022 at 8:32 PM Lad Prabhakar
> <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> > Supported GPIO IRQs by the chip is not always equal to the number of GPIO
> > pins. For example on Renesas RZ/G2L SoC where it has GPIO0-122 pins but at
> > a give point a maximum of only 32 GPIO pins can be used as IRQ lines in
> > the IRQC domain.
> >
> > This patch adds ngirq member to struct gpio_irq_chip and passes this as a
> > size to irq_domain_create_hierarchy()/irq_domain_create_simple() if it is
> > being set in the driver otherwise fallbacks to using ngpio.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Thanks for your patch!
>
> > --- a/drivers/gpio/gpiolib.c
> > +++ b/drivers/gpio/gpiolib.c
> > @@ -1221,7 +1221,7 @@ static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
> > gc->irq.domain = irq_domain_create_hierarchy(
> > gc->irq.parent_domain,
> > 0,
> > - gc->ngpio,
> > + gc->irq.ngirq ?: gc->ngpio,
> > gc->irq.fwnode,
> > &gc->irq.child_irq_domain_ops,
> > gc);
> > @@ -1574,7 +1574,7 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc,
> > } else {
> > /* Some drivers provide custom irqdomain ops */
> > gc->irq.domain = irq_domain_create_simple(fwnode,
> > - gc->ngpio,
> > + gc->irq.ngirq ?: gc->ngpio,
> > gc->irq.first,
> > gc->irq.domain_ops ?: &gpiochip_domain_ops,
> > gc);
>
> OK.
>
> gpiochip_irqchip_remove() does:
>
> /* Remove all IRQ mappings and delete the domain */
> if (gc->irq.domain) {
> unsigned int irq;
>
> for (offset = 0; offset < gc->ngpio; offset++) {
> if (!gpiochip_irqchip_irq_valid(gc, offset))
>
> Hence it relies on gc->irq.valid_mask, which I think is OK in general.
>
Agreed.

> continue;
>
> irq = irq_find_mapping(gc->irq.domain, offset);
> irq_dispose_mapping(irq);
> }
>
> irq_domain_remove(gc->irq.domain);
>
> }
>
> > --- a/include/linux/gpio/driver.h
> > +++ b/include/linux/gpio/driver.h
> > @@ -51,6 +51,14 @@ struct gpio_irq_chip {
> > */
> > const struct irq_domain_ops *domain_ops;
> >
> > + /**
> > + * @ngirq:
> > + *
> > + * The number of GPIO IRQ's handled by this IRQ domain; usually is
> > + * equal to ngpio.
>
> "If not set, ngpio will be used."
>
sure will update the comment.

Cheers,
Prabhakar

> > + */
> > + u16 ngirq;
> > +
> > #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> > /**
> > * @fwnode:
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> 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