Re: [PATCH v3] Input: gpio_keys: Add level trigger support for GPIO keys

[Baolin Wang]

On 28 February 2018 at 22:44, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Wed, Feb 28, 2018 at 1:44 PM, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
>> On some platforms (such as Spreadtrum platform), the GPIO keys can only
>> be triggered by level type. So this patch introduces one property to
>> indicate if the GPIO trigger type is level trigger or edge trigger.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>> ---
>> Changes since v2:
>>  - Use 'interrupt' property to indicate the irq type.
>>
>> Changes since v1:
>>  - Diable the GPIO irq until reversing the GPIO level type.
>
> I've looked at your patch in more detail now, and given it a bit more thought.
>
> I wonder if you could move that logic into your gpiochip/irqchip driver instead.
> It seems that what you do in the gpio-keys driver is to emulate edge triggered
> behavior on a level triggered irqchip.
>
> If you put the same logic into the gpio driver, you could simply make it
> pretend to support an edge trigger on both edges and call into the interrupt
> handler whenever the state changes.
>

That is really a good suggestion, which can avoid duplicate level
reverse logic in different drivers. So this patch can be simplified
just adding one trigger_type to indicate the interrupt type (not
always edge trigger). Thanks for your suggestion.

-- 
Baolin.wang
Best Regards