Re: [PATCH 1/3] ARM: at91/aic: add device tree support for AIC

Jean-Christophe PLAGNIOL-VILLARD
2011-11-25T14:50:57Z

On 22:26 Thu 24 Nov , Jamie Iles wrote:
> Hi Nicolas,
>
> On Thu, Nov 24, 2011 at 10:56:27PM +0100, Nicolas Ferre wrote:
> > Ioremap registers from DT specification and adding
> > of a simple irq domain for AIC interrupts.
> >
> > Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> > Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> > ---
>
> Apologies if I've missed it somewhere but I think this needs to be
> documented in Documentation/devicetree.
>
> [...]
> > diff --git a/arch/arm/mach-at91/irq.c b/arch/arm/mach-at91/irq.c
> > index be6b639..80783b0 100644
> > --- a/arch/arm/mach-at91/irq.c
> > +++ b/arch/arm/mach-at91/irq.c
> > @@ -24,6 +24,8 @@
> > #include <linux/module.h>
> > #include <linux/mm.h>
> > #include <linux/types.h>
> > +#include <linux/of_address.h>
> > +#include <linux/irqdomain.h>
> >
> > #include <mach/hardware.h>
> > #include <asm/irq.h>
> > @@ -34,6 +36,7 @@
> > #include <asm/mach/map.h>
> >
> > void __iomem *at91_aic_base;
> > +static struct irq_domain at91_aic_domain;
> >
> > static void at91_aic_mask_irq(struct irq_data *d)
> > {
> > @@ -127,14 +130,44 @@ static struct irq_chip at91_aic_chip = {
> > .irq_set_wake = at91_aic_set_wake,
> > };
> >
> > +#if defined(CONFIG_OF)
> > +static struct of_device_id aic_ids[] = {
> > + { .compatible = "atmel,at91rm9200-aic" },
> > + { /*sentinel*/ }
> > +};
> > +
> > +static int __init at91_aic_of_init(void)
> > +{
> > + struct device_node *np;
> > +
> > + np = of_find_matching_node(NULL, aic_ids);
> > + if (np == NULL)
> > + return -ENODEV;
> > +
> > + at91_aic_base = of_iomap(np, 0);
> > + at91_aic_domain.of_node = np;
>
> I think this needs to be:
>
> at91_aic_domain.of_node = of_node_get(np);
>
> to keep the reference count.
>
> > + /* Keep refcount of the node */
> > +
> > + return 0;
> > +}
> > +#else
> > +static int __init at91_aic_of_init(void)
> > +{
> > + return -ENOSYS;
> > +}
> > +#endif
>
> I think it's preferred if you use of_irq_init() here as it can handle
> the ordering of IRQ controllers. There are GIC and VIC bindings in
> -next that use this and provide a way for non-DT platforms to still use
> the drivers.
which is the case here as if the of_init fail we failback to the non-dt init

and this IP is AT91 only

Best Regards,
J.
>
> > /*
> > * Initialize the AIC interrupt controller.
> > */
> > void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
> > {
> > unsigned int i;
> > + int ret;
> >
> > - at91_aic_base = ioremap(AT91_AIC, 512);
> > + ret = at91_aic_of_init();
> > + if (ret < 0)
> > + at91_aic_base = ioremap(AT91_AIC, 512);
> >
> > if (!at91_aic_base)
> > panic("Impossible to ioremap AT91_AIC\n");
> > @@ -169,4 +202,10 @@ void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
> > /* Disable and clear all interrupts initially */
> > at91_aic_write(AT91_AIC_IDCR, 0xFFFFFFFF);
> > at91_aic_write(AT91_AIC_ICCR, 0xFFFFFFFF);
> > +
> > + /* Add irq domain for AIC */
> > + at91_aic_domain.irq_base = at91_aic_domain.hwirq_base = 0;
> > + at91_aic_domain.nr_irq = NR_AIC_IRQS;
> > + at91_aic_domain.ops = &irq_domain_simple_ops;
>
> irq_domain_simple_ops is only exported when CONFIG_OF_IRQ=y, so this
> probably won't work for !CONFIG_USE_OF.
so we need to use
if (IS_BUILT_IN(CONFIG_USE_OF)) {
}

Best Regards,
J.