Re: [PATCH v2] ARM: at91: pit add DT support

[Jamie Iles <jamie-wmLquQDDieKakBO8gow8eQ@public.gmane.org>]

On Thu, Jan 05, 2012 at 03:50:09PM +0100, Nicolas Ferre wrote:
> On 01/05/2012 01:00 PM, Jamie Iles :
> > Hi Nicolas, Jean-Christophe,
> > 
> > On Thu, Jan 05, 2012 at 02:48:28PM +0100, Nicolas Ferre wrote:
> >> From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>
> >>
> >> Retreive registers address and IRQ from device tree entry. Fall back
> >> to built-in values if an error occurs.
> >>
> >> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>
> >> [nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org: change error path and interrupts property handling]
> >> Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> >> ---
> > [...]
> >> diff --git a/arch/arm/mach-at91/at91sam926x_time.c 
> >> b/arch/arm/mach-at91/at91sam926x_time.c
> >> index d89ead7..5d4c308 100644
> >> --- a/arch/arm/mach-at91/at91sam926x_time.c
> >> +++ b/arch/arm/mach-at91/at91sam926x_time.c
> >> @@ -14,6 +14,8 @@
> > [...]
> >> +static int __init of_at91sam926x_pit_init(void)
> >> +{
> >> +	struct device_node *np;
> >> +
> >> +	np = of_find_matching_node(NULL, timer_ids);
> >> +	if (!np)
> >> +		goto err;
> >> +
> >> +	pit_base_addr = of_iomap(np, 0);
> >> +	if (!pit_base_addr)
> >> +		goto node_err;
> >> +
> >> +	/* Get the interrupts property */
> >> +	if (of_property_read_u32(np, "interrupts", &at91sam926x_pit_irq.irq))
> >> +		goto ioremap_err;
> > 
> > I think you want:
> > 
> > 	at91sam926x_pit_irq.irq = irq_of_parse_and_map(np, 0);
> > 
> > to make sure the IRQ is converted to a Linux IRQ and not a hwirq.
> 
> Yes, that definitively makes sense. BTW, without a DT entry, how should
> I map a hwirq, with the irq_domain_to_irq() helper? But I will need
> access to the interrupt controller "struct irq_domain"...

If you aren't booting with DT then at the moment I think on AT91 you 
have statically assigned irq_descs and IRQ numbers so you don't need to 
map them, you just know what IRQ number to request at compile time.

Jamie