Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Fri, 13 May 2022 08:53:38 +0200 | Subject | Re: [PATCH v3 5/5] pinctrl: renesas: pinctrl-rzg2l: Add IRQ domain to handle GPIO interrupt |
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Hi Prabhakar,
On Thu, May 12, 2022 at 7:36 PM Lad, Prabhakar <prabhakar.csengg@gmail.com> wrote: > On Thu, May 12, 2022 at 8:39 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > On Wed, May 11, 2022 at 8:32 PM Lad Prabhakar > > <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote: > > > Add IRQ domian to RZ/G2L pinctrl driver to handle GPIO interrupt. > > > GPIO0-GPIO122 pins can be used as IRQ lines but only 32 pins can be > > > used as IRQ lines at given time. Selection of pins as IRQ lines > > > is handled by IA55 (which is the IRQC block) which sits in between the > > > GPIO and GIC. > > > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> > > > > Thanks for your patch! > > > > > --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c > > > +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c > > > > > static int rzg2l_gpio_register(struct rzg2l_pinctrl *pctrl) > > > { > > > struct device_node *np = pctrl->dev->of_node; > > > struct gpio_chip *chip = &pctrl->gpio_chip; > > > const char *name = dev_name(pctrl->dev); > > > + struct irq_domain *parent_domain; > > > struct of_phandle_args of_args; > > > + struct device_node *parent_np; > > > + struct gpio_irq_chip *girq; > > > int ret; > > > > > > + parent_np = of_irq_find_parent(np); > > > + if (!parent_np) > > > + return -ENXIO; > > > + > > > + parent_domain = irq_find_host(parent_np); > > > + of_node_put(parent_np); > > > + if (!parent_domain) > > > + return -EPROBE_DEFER; > > > + > > > ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &of_args); > > > if (ret) { > > > dev_err(pctrl->dev, "Unable to parse gpio-ranges\n"); > > > @@ -1138,6 +1330,15 @@ static int rzg2l_gpio_register(struct rzg2l_pinctrl *pctrl) > > > chip->base = -1; > > > chip->ngpio = of_args.args[2]; > > > > > > + girq = &chip->irq; > > > + girq->chip = &rzg2l_gpio_irqchip; > > > + girq->fwnode = of_node_to_fwnode(np); > > > + girq->parent_domain = parent_domain; > > > + girq->child_to_parent_hwirq = rzg2l_gpio_child_to_parent_hwirq; > > > + girq->populate_parent_alloc_arg = rzg2l_gpio_populate_parent_fwspec; > > > + girq->child_irq_domain_ops.free = rzg2l_gpio_irq_domain_free; > > > + girq->ngirq = RZG2L_TINT_MAX_INTERRUPT; > > > + > > > > I think you need to provide a .init_valid_mask() callback, as > > gpiochip_irqchip_remove() relies on that for destroying interrupts. > Are you suggesting the callback to avoid looping through all the GPIO pins?
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)) continue;
irq = irq_find_mapping(gc->irq.domain, offset); irq_dispose_mapping(irq); }
irq_domain_remove(gc->irq.domain);
}
The main thing is not about avoiding to loop through all GPIO pins, but to avoid irq_{find,dispose}_mapping() doing the wrong thing. The loop is over all GPIO offsets, while not all of them are mapped to valid interrupts. Does the above work correctly?
> > However, the mask will need to be dynamic, as GPIO interrupts can be > > mapped and unmapped to one of the 32 available interrupts dynamically, > > right? > Yep that's correct. > > > I'm not sure if that can be done easily: if gpiochip_irqchip_irq_valid() > > is ever called too early, before the mapping is done, it would fail. > > > The mask initialization is a one time process and that is during > adding the GPIO chip. At this stage we won't be knowing what will be > the valid GPIO pins used as interrupts. Maybe the core needs to > implement a callback which lands in the GPIO controller driver to tell > if the gpio irq line is valid. This way we can handle dynamic > interrupts.
Upon closer look, I think the mask is a red herring, and we don't need it. But we do need to handle the (possible) mismatch between GPIO offset (index) and IRQ offset in the above code.
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
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