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

Jamie Iles
2011-11-25T15:28:22Z

On Fri, Nov 25, 2011 at 02:51:06PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 22:26 Thu 24 Nov , Jamie Iles wrote:
> > Hi Nicolas,
> > On Thu, Nov 24, 2011 at 10:56:27PM +0100, Nicolas Ferre wrote:
[...]
> > > +#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

Right, but it's not using the of_irq_init() interface which is the
standard way of registering interrupt controllers and will correctly
dependencies for you.

So if you could have something like:

void __init __at91_aic_init(unsigned int priority[NR_AIC_IRQS],
void __iomem *regs,
struct device_node *np)
{
/*
* Do all of the writes to the AIC itself and configure
* the IRQ domain.
*/
}

void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
{
void __iomem *base = ioremap(AT91_AIC, 512);

__at91_aic_init(priority, base, NULL);
}

int __init at91_aic_of_init(struct device_node *node,
struct device_node *parent)
{
void __iomem *regs = of_iomap(node, 0);

/*
* Get priorities from the DT. If this was an array of cells
* then that should be okay.
*/
__at91_aic_init(dt_priorities, regs, node);
}

Then the DT based board initialisation can do:

static const struct of_device_id at91_irq_of_match[] __initconst = {
{ .compatible = "atmel,at91-aic", .data = at91_aic_of_init },
{}
};

static void __init at91_of_irq_init(void)
{
of_irq_init(at91_of_irq_init);
}

Which is consistent with other platforms. However this does require
that the priorities are encoded in the device-tree, but I guess that's a
good thing anyway isn't it?

Jamie