Hi Thomas,

On Mon, 12 May 2025 at 16:30, Thomas Richard [off-list ref] wrote:

On 5/12/25 16:11, Andy Shevchenko wrote:

quoted

On Mon, May 12, 2025 at 04:08:35PM +0200, Thomas Richard wrote:

quoted

On 5/9/25 11:07, Geert Uytterhoeven wrote:

quoted

On Tue, 6 May 2025 at 17:21, Thomas Richard [off-list ref] wrote:

...

quoted

quoted

quoted

+int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
+                       unsigned long config);
+
+int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset);

I would expect all of these to take gpiochip_fwd pointers instead of
gpio_chip pointers.  What prevents you from passing a gpio_chip pointer
that does not correspond to a gpiochip_fwd object, causing a crash?

Indeed nothing prevents from passing gpio_chip pointer which does not
correspond to a gpiochip_fwd object.
And it is also a bit weird to pass a gpiochip_fwd pointer in some cases
(for example gpio_fwd_gpio_add()) and a gpio_chip in other cases.

I can keep GPIO operations as is, and create exported wrappers which
take a gpiochip_fwd pointer as parameter, for example:

int gpiochip_fwd_get_multiple(struct gpiochip_fwd *fwd,
                           unsigned long *mask,
                           unsigned long *bits)
{
     struct gpio_chip *gc = gpiochip_fwd_get_gpiochip(fwd);

     return gpio_fwd_get_multiple_locked(chip, mask, bits);
}
EXPORT_SYMBOL_NS_GPL(gpiochip_fwd_get_multiple, "GPIO_FORWARDER");

So exported functions are gpiochip_fwd_*().

Sounds good for me. Let's wait for Geert's opinoin on this.

Regarding Geert's comment for patch 9/12, an other proposal for naming:
As mentioned above, exported functions gpiochip_fwd_*() take a
gpiochip_fwd as parameter.

But for all functions corresponding to a GPIO operation add the gpio
word, and for functions to add/remove GPIO descriptor add the desc word:

devm_gpiochip_fwd_alloc()
gpiochip_fwd_register()

gpiochip_fwd_desc_add()
gpiochip_fwd_desc_free()

gpiochip_fwd_get_gpiochip()
gpiochip_fwd_get_data()

gpiochip_fwd_gpio_request()
gpiochip_fwd_gpio_get_direction()
gpiochip_fwd_gpio_direction_input()
gpiochip_fwd_gpio_direction_output()
gpiochip_fwd_gpio_get()
gpiochip_fwd_gpio_set()
gpiochip_fwd_gpio_set_multiple()
gpiochip_fwd_gpio_get_multiple()
gpiochip_fwd_gpio_set_config()
gpiochip_fwd_gpio_to_irq()

Sounds good to me (from a quick glance).

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds