Re: [RFC PATCH] RFC: drivers: gpio: helper for generic pin IRQ handling

[Andy Shevchenko]

On Tue, Dec 8, 2020 at 4:14 PM Enrico Weigelt, metux IT consult
<info@xxxxxxxxx> wrote:
>
> Many gpio drivers already use gpiolib's builtin irqchip handling
> (CONFIG_GPIOLIB_IRQCHIP), but still has some boilerplate for retrieving
> the actual Linux IRQ number and calling into the generic handler.
> That boilerplate can be reduced by moving that into a helper function.
>
> This is an RFC patch to outline how that could be done. Note: it's
> completely untested yet.
>
> Several drivers still have their completely IRQ own implementation and
> thus can't be converted yet. Some of them perhaps could be changed to
> store their irq domain in the struct gpio, so the new helper could
> also be used for those.
>
> Having all GPIO drivers doing their IRQ management entirely through the
> GPIO subsystem (eg. never calling generic_handle_irq() and using the builtin
> IRQ handling) would also allow a more direct (eg. callback-based) pin change
> notification for GPIO consumers, that doesn't involve registering them as
> generic IRQ handlers.
>
> Further reduction of boilerplate could be achieved by additional helpers
> for common patterns like for_each_set_bit() loops on irq masks.

Have you able to test them all?
As the PCA953x case showed us this is not so simple, besides the name
which sucks — we don't *raise* and IRQ we *handle* it.

NAK.

-- 
With Best Regards,
Andy Shevchenko