Re: [PATCH v1 5/5] gpiolib: Replace open coded gpiochip_irqchip_add_allocated_domain()

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Fri, Jun 30, 2023 at 3:58 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:

> While at it, I would like to ask on ->to_irq() callback. IIUC
> assigning it with an IRQ chip makes a dead code in the driver. Am I
> correct?

It's fine to assign it with an IRQ chip but not with GPIOLIB_IRQCHIP,
i.e. gc->irq better be NULL.

> If not, can somebody shed some light on how the RT5677
> driver, for example, works with GPIO IRQ?

That is theoretically fine (I don't know this HW in particular).
It looks a bit fragile...

It's just a helper to translate a GPIO line to the corresponding Linux
IRQ number and when using GPIOLIB_IRQCHIP the GPIO core
will do this using the irqdomain, else it is up to the driver.

Yours,
Linus Walleij