Re: [PATCH] pinctrl: samsung: Calculate GPIO base for pinctrl_add_gpio_range

From: Tomasz Figa
Date: Sun Feb 26 2017 - 21:16:22 EST


Hi Charles,

2017-02-24 2:54 GMT+09:00 Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>:
> As the pinctrl is now added before the GPIOs are registered we need to
> manually calculate what the GPIO base will be, otherwise the base for
> each gpio_range will be set to zero. Fortunately the driver
> already assigns a GPIO base, in samsung_gpiolib_register, and uses the
> same calculation it does for the pin_base. Meaning the two will always
> be the same and allowing us to reuse the pinbase and avoid the issue.

Please see my comment inline.

>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
>
> Ok I might have spoken to soon there looks like there is a simple
> way to fix this up, at least in this case. It would be much more
> of an issue if the driver allocated its GPIO base dynamically.
>
> Thanks,
> Charles
>
> drivers/pinctrl/samsung/pinctrl-samsung.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.c b/drivers/pinctrl/samsung/pinctrl-samsung.c
> index ddc8d6b..864d8b4d 100644
> --- a/drivers/pinctrl/samsung/pinctrl-samsung.c
> +++ b/drivers/pinctrl/samsung/pinctrl-samsung.c
> @@ -882,7 +882,7 @@ static int samsung_pinctrl_register(struct platform_device *pdev,
> pin_bank->grange.id = bank;
> pin_bank->grange.pin_base = drvdata->pin_base
> + pin_bank->pin_base;
> - pin_bank->grange.base = pin_bank->gpio_chip.base;
> + pin_bank->grange.base = pin_bank->grange.pin_base;

If we are not reading the base from the GPIO bank anymore, maybe it
could make sense to actually make samsung_gpiolib_register() use
bank->grange.base as gc->base? This way we would avoid explicitly
numbering two times.

Best regards,
Tomasz