[PATCH 13/25] OMAP4: PM: Add WakeupGen module as OMAP gic_arch_extn

Tony,
On Wed, Sep 14, 2011 at 2:06 AM, Tony Lindgren [off-list ref] wrote:

* Santosh Shilimkar [off-list ref] [110904 06:23]:

quoted

OMAP WakeupGen is the interrupt controller extension used along
with ARM GIC to wake the CPU out from low power states on
external interrupts.

The WakeupGen unit is responsible for generating wakeup event
from the incoming interrupts and enable bits. It is implemented
in MPU always ON power domain. During normal operation,
WakeupGen delivers external interrupts directly to the GIC.

...

quoted

+ ? ? /*
+ ? ? ?* Override GIC architecture specific functions to add
+ ? ? ?* OMAP WakeupGen interrupt controller along with GIC
+ ? ? ?*/
+ ? ? gic_arch_extn.irq_mask = wakeupgen_mask;
+ ? ? gic_arch_extn.irq_unmask = wakeupgen_unmask;
+ ? ? gic_arch_extn.irq_set_wake = wakeupgen_set_wake;
+ ? ? gic_arch_extn.flags = IRQCHIP_MASK_ON_SUSPEND;

As I've commented before, there should not be any need to tweak
the wakeupgen registers for each interrupt during the runtime.

And I gave you all the reasons why it needs to be done this way.

AFAIK the wakeupgen registers only need to be armed every time
before entering idle.

No that doesn't work and it completely hacky approach.
This problem is for all SOC's using A9 SMP and GIC and every soc
has an architecture specific interrupt controller extension. And that
was the reason the GIC arch_extn was proposed.
It's just another IRQCHIP and works seamlessly being part of the
framework.  And it will also initialized with primary IRQCHIP( GIC).

Regards
Santosh