Re: [PATCH v3 1/3] gpio: vf610: add support to DT 'ngpios' property

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Thu, Jan 18, 2024 at 10:25 AM Hector Palacios
<hector.palacios@xxxxxxxx> wrote:
> On 1/17/24 21:51, Andy Shevchenko wrote:
> >> Some SoCs, such as i.MX93, don't have all 32 pins available
> >> per port. Allow optional generic 'ngpios' property to be
> >> specified from the device tree and default to
> >> VF610_GPIO_PER_PORT (32) if the property does not exist.

...

> >> +       ret = device_property_read_u32(dev, "ngpios", &ngpios);
> >> +       if (ret || ngpios > VF610_GPIO_PER_PORT)
> >> +               gc->ngpio = VF610_GPIO_PER_PORT;
> >> +       else
> >> +               gc->ngpio = (u16)ngpios;
> >
> > This property is being read by the GPIOLIB core. Why do you need to repeat this?
>
> My apologies; I had not seen this.
> I'll use gpiochip_get_ngpios() on the next iteration.

But still why?
https://elixir.bootlin.com/linux/latest/source/drivers/gpio/gpiolib.c#L867

It's called for every driver.

Maybe it's needed to be refactored to allow fallbacks? Then can the
GPIO MMIO case also be updated?

-- 
With Best Regards,
Andy Shevchenko