Re: [RFC PATCH 3/5] gpio: generic: add io_port to struct gpio_generic_chip

[Linus Walleij]

On Tue, Apr 7, 2026 at 8:49 PM Jose Javier Rodriguez Barbarin
<dev-josejavier.rodriguez@xxxxxxxxxx> wrote:

> @@ -645,6 +645,7 @@ int gpio_generic_chip_init(struct gpio_generic_chip *chip,
>         gc->base = -1;
>         gc->request = gpio_mmio_request;
>         chip->be_bits = !!(flags & GPIO_GENERIC_BIG_ENDIAN);
> +       chip->io_port = !!(flags & GPIO_GENERIC_PORT_MAPPED);

Actually, if you follow my idead to use a special config for port-based
chips, struct gpio_generic_port_chip_config, that means that you will
need to refactor-split this:

int gpio_generic_chip_init(struct gpio_generic_chip *chip,
                           const struct gpio_generic_chip_config *cfg)

Something like this:

static int gpio_generic_chip_init_common(struct gpio_generic_chip *chip,
    unsigned long flags, struct device *dev)

int gpio_generic_chip_init(struct gpio_generic_chip *chip,
                           const struct gpio_generic_chip_config *cfg)

int gpio_generic_port_chip_init(struct gpio_generic_chip *chip,
                           const struct gpio_generic_port_chip_config *cfg)

(Those prototypes half-guessed by looking at the code...)

So that each variant calls the common code for the generic part and
the MMIO-only respective port-only portions are kept inside
the specialized init functions, with gpio_generic_port_chip_init()
ifdef:ed out for !PORT_IO.

In that case, chip->io_port can just uncoditionally be assigned
true from gpio_generic_port_chip_init() and you don't even need
the special flag for port mapped IO.

Yours,
Linus Walleij