Re: [PATCH v1 5/5] gpio: pca953x: Override GpioInt() pin for Intel Galileo Gen 2

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Mon, May 25, 2020 at 12:45:53PM +0300, Mika Westerberg wrote:
> On Mon, May 25, 2020 at 12:31:50PM +0300, Andy Shevchenko wrote:
> > On Mon, May 25, 2020 at 12:20:28PM +0300, Mika Westerberg wrote:
> > > On Thu, May 21, 2020 at 12:19:16AM +0300, Andy Shevchenko wrote:
> > > > ACPI table on Intel Galileo Gen 2 has wrong pin number for IRQ resource
> > > > of one of the I²C GPIO expanders. ACPI GPIO library provides a special
> > > > quirk which we may use in this case. With help of it, override GpioInt()
> > > > pin for the affected platform.

...

> > > > +static const struct acpi_gpio_params pca953x_interrupt_gpios = { 0, 0, true };
> > > > +
> > > > +static const struct acpi_gpio_mapping pca953x_acpi_interrupt_gpios[] = {
> > > > +	{ "interrupt-gpios", &pca953x_interrupt_gpios, 1, ACPI_GPIO_QUIRK_FORCE_PIN, 1 },
> > > > +	{ }
> > > > +};
> > > > +
> > > > +static int pca953x_acpi_interrupt_get_irq(struct device *dev)
> > > > +{
> > > > +	struct gpio_desc *desc;
> > > > +
> > > > +	if (devm_acpi_dev_add_driver_gpios(dev, pca953x_acpi_interrupt_gpios))
> > > > +		dev_warn(dev, "can't add GPIO ACPI mapping\n");
> > > > +
> > > > +	desc = devm_gpiod_get(dev, "interrupt", GPIOD_IN);
> > > > +	if (IS_ERR(desc))
> > > > +		return PTR_ERR(desc);
> > > > +
> > > > +	return gpiod_to_irq(desc);
> > > > +}
> > > > +
> > > > +static const struct dmi_system_id pca953x_dmi_acpi_interrupt_info[] = {
> > > > +	{
> > > > +		.ident = "Intel Galileo Gen 2",
> > > > +		.matches = {
> > > > +			DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"),
> > > > +		},
> > > > +	},
> > > > +	{}

> > > Since you do everything already in this driver, I think we can live
> > > without adding ACPI_GPIO_QUIRK_FORCE_PIN to the core code at all.

> > Hmm... I don't see how (perhaps need morning coffee). Any pointers?

> Well you already know all the details in this driver, no? Why you need
> to pass any of this information to the core and the back to the same
> driver?

Due to parsing of ACPI tables. I don't want to copy'n'paste 25% of
gpiolib-acpi.c in here. I think provided solution is cleaner and (more)
flexible in terms of maintenance.

-- 
With Best Regards,
Andy Shevchenko