Re: [PATCH 2/2] gpio-f7188x: filter non-export gpio for F81866

[Peter Hung]

Hi Simon,

> > @@ -351,6 +485,15 @@ static int f7188x_gpio_probe(struct platform_device *pdev)
> >   	for (i = 0; i < data->nr_bank; i++) {
> >   		struct f7188x_gpio_bank *bank = &data->bank[i];
> >
> > +		/*
> > +		 * Dont export GPIO sysfs if pin set is not enable by MB
> > +		 * manufacturer.
>
> What does MB stands for ?

The MB is stands for "Motherboard", Due to the limit of 80 words length,
I use the abbreviation.

> > +		 */
> > +		if (sio->type == f81866 && f81866_verify_gpioset(sio->addr, i))
> > +			continue;
>
> This whole filtering mechanism relies on the fact that the multiplexing
> configuration has been correctly applied by the BIOS (if applied at
> all). But I wonder if it is often the case. For example, I have several
> boards for which it is not true. And to make the GPIOs available, I need
> first to fix the multiplexing pin configuration of the Super I/O.
>
> Maybe it would be more correct to rely on the hardware description of a
> board (Device Tree or ACPI) to decide which GPIO bank can be enabled or
> not.

That's good for control by Device Tree or ACPI.

IMO, we shouldn't export GPIOs not enabled if the BIOS had written
wrong configuration to SuperIO, but it's only my opinion. Should I
do filter for this?

Thanks for your advices.
--
With Best Regards,
Peter Hung