Re: [PATCH v2 0/2] Add GPIO level-sensitive interrupt support

[Alexandre Torgue]

Hi Marek

On 2/18/20 5:25 PM, Marek Vasut wrote:
> On 2/18/20 2:12 PM, Alexandre Torgue wrote:
> > This series adds the possibility to handle gpio interrupts on level.
> >
> > GPIO hardware block is directly linked to EXTI block but EXTI handles
> > external interrupts only on edge. To be able to handle GPIO interrupt on
> > level a "hack" is done in gpio irq chip: parent interrupt (exti irq chip)
> > is retriggered following interrupt type and gpio line value.
> >
> > In exti irq chip, retrigger ops function is added.
>
> btw. this might be unrelated, but is it possible to have e.g. gpioC2 set
> as trigger-level-low and gpioD2 set as trigger-edge-falling ? It seems
> 8eb2dfee9fb1 ("pinctrl: stm32: add lock mechanism for irqmux selection")
> prevents that.

No it's not possible. Each gpio line doesn't have a dedicated Exti line 
Each Exti line is muxing between gpio banks.

Mapping is done as following:

EXTI0 = A0 or B0 or C0 .... or Z0 : selected by Mux
EXTI1 = A1 or B1 or C1 ....or Z1 : selected by Mux
EXTI2 = A2 or B2 or C2 ....or Z2 : selected by Mux
...

regards
Alexandre