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SubjectRe: [RFC] gpio/omap: auto-setup a GPIO when used as an IRQ
Javier,

On Monday 23 September 2013 01:07 PM, Tony Lindgren wrote:
> * Javier Martinez Canillas <javier.martinez@collabora.co.uk> [130923 10:09]:
>> On 09/23/2013 06:45 PM, Tony Lindgren wrote:
>>>
>>> Hmm does this still work for legacy platform data based
>>> drivers that are doing gpio_request() first?
>>>
>>
>> Yes it still work when booting using board files. I tested on my OMAP3 board and
>> it worked in both DT and legacy booting mode.
>
> OK great.
>
>>> And what's the path for clearing things for PM when free_irq()
>>> gets called? It seems that this would leave the GPIO bank
>>> enabled causing a PM regression?
>>>
>>
>> Indeed, I did set bank->mod_usage |= 1 << offset so the bank is enabled if the
>> device goes to suspended and then resumed but I completely forget about the
>> clearing path when the IRQ is freed.
>>
>> Which makes me think that we should probably maintain two usage variables, one
>> for GPIO and another one for IRQ and check both of them on the suspend/resume pm
>> functions.
>
> Yes that it seems that they should be treated separately.
>
As discussed on IRC, the patch as such is fine after the mentioned fixup,
I would like to hear back if Linus W/Grant is fine with the approach. Not sure
if I missed the discussion, but the proposed patch is deviation from
traditional method of doing gpio_request() first up to perform other
gpio operations.

Regards,
Santosh




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