[PATCH 2/4] arm: exynos4: add irq_domain support for wakeup interrupts

[Thomas Abraham]

Hi Rob,

On 7 December 2011 21:54, Rob Herring <robherring2 at gmail.com> wrote:
> Thomas,
>
> On 12/07/2011 07:59 AM, Thomas Abraham wrote:
>> Add irq_domain support for the 32 wakeup interrupt sources.
>>
>> Cc: Grant Likely <grant.likely at secretlab.ca>
>> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
>> ---
>>  arch/arm/mach-exynos/include/mach/regs-gpio.h |    4 +-
>>  arch/arm/mach-exynos/irq-eint.c               |   69 ++++++++++++++++---------
>>  2 files changed, 46 insertions(+), 27 deletions(-)
>>
>
> [snip]
>
>> @@ -193,22 +199,35 @@ static void exynos4_irq_eint0_15(unsigned int irq, struct irq_desc *desc)
>>
>>  int __init exynos4_init_irq_eint(void)
>>  {
>> -     int irq;
>> +     int irq, hwirq;
>> +     struct irq_domain *domain = &exynos4_eint_irq_domain;
>> +
>> +     domain->irq_base = irq_alloc_descs(IRQ_EINT(0), IRQ_EINT(0),
>
> Can this be dynamic and remove any compile time knowledge of the irq base?

There are macros in the mach-exynos code that define linux irq numbers
for specific uses. For instance, linux interrupt number for wakeup
interrupt 0 is defined as IRQ_EINT(0) and maps to one of the linux irq
number. Consumer using this interrupt would use IRQ_EINT(0) in
request_irq or setup_irq.

Since the linux irq numbers are currently assigned to specific uses
like this, I am not sure how to make irq_alloc_descs dynamic and still
be able to use the dynamic irq base in the rest of the mach-exynos
code with no other code changes. Is there any way to handle this case?

Thanks,
Thomas.

>
>> +                                             EXYNOS4_EINT_NR, 0);
>> +     if (domain->irq_base < 0) {
>> +             pr_err("exynos4_init_irq_eint: Failed to alloc irq descs\n");
>> +             return -EBUSY;
>
> You will hit this error with sparse irq unless you set nr_irq in mach
> desc to NR_IRQ_LEGACY (16).

[...]