Mika Westerberg [off-list ref] writes:

If it suits you, I would go with the "can_disable" -field in the
struct gpio_keys_button. This way it should be possible to extend
gpio-keys in future to support multiple buttons sharing the single IRQ
and it also works for us.

Why not simply release the corresponding IRQ?  No new fields are needed
in the platform data, you don't even have to change the IRQ flags.  Or
do I miss something again?  Could well be, I'm starting to lose ground
in this discussion... this runtime PM stuff is rather confusing. :]
-- 
Cheers,
Feri.