[MinnowBoard] how to enable gpio wake up function

[xing_wei at linux.intel.com]

> I'm working on the minnowmax board, and i want the gpio 84(GPIO_S5_4) to
> be a wakeup source that can
> wake up the system from S3 like the switch key does on board.
> My yocto linux kernel version is 3.14.4.
> I've referenced the doc named
> "510858_BayTrail_I_SoC_External_Design_Spec_r1p0" and the kernel driver
> code named pinctrl-baytrail.c.
> The registers about gpio in baytrail are divided into kinds, IO access
> registers and memory mapped access registers.
> The pinctrl-baytrail.c just read/write memory mapped access register.
> Seems like no corresponding bit in memory mapped access register can
> enable the wake up function.
> My operation is request gpio 84 first, then request a interrupt with
> IRQF_TRIGGER_RISING, IRQF_TRIGGER_FALLING, IRQF_ONESHOT, IRQF_NO_SUSPEND.
> And irq function works during kernel runtime, but can't wake the system up
> from S3.
> My question is how to use GPIO_S5 as a wake up source on minnowmax board?
> Expect your help.
> Thanks.
> _______________________________________________
> elinux-MinnowBoard mailing list
> elinux-MinnowBoard at lists.elinux.org
> http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
>

anybody has the experience or hint about this question?