[PATCH] gpiolib: fix bug and clarify OF use of ranges

[Viresh Kumar]

On 21 November 2012 13:07, Linus Walleij <linus.walleij at stericsson.com> wrote:
> From: Linus Walleij <linus.walleij at linaro.org>
>
> In commit c905165f5946f56dca195871641bd4e488eca24a
> "gpiolib: let gpiochip_add_pin_range() specify offset"
> I forgot to update the OF use of the function
> gpiochip_add_pin_range().
>
> It turns out that this reveal a weakness in the
> OF range mappings: ranges cannot currently be sparse.
> So put in a comment so we can fix this later.
>
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> ---
>  drivers/gpio/gpiolib-of.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index a40cd84..d542a14 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -238,8 +238,20 @@ static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
>                 if (!pctldev)
>                         break;
>
> +               /*
> +                * This assumes that the n GPIO pins are consecutive in the
> +                * GPIO number space, and that the pins are also consecutive
> +                * in their local number space. Currently it is not possible
> +                * to add different ranges for one and the same GPIO chip,
> +                * as the code assumes that we have one consecutive range
> +                * on both, mapping 1-to-1.
> +                *
> +                * TODO: make the OF bindings handle multiple sparse ranges
> +                * on the same GPIO chip.
> +                */
>                 ret = gpiochip_add_pin_range(chip,
>                                              pinctrl_dev_get_name(pctldev),
> +                                            0, /* offset in gpiochip */
>                                              pinspec.args[0],
>                                              pinspec.args[1]);

Reviewed-by: Viresh Kumar <viresh.kumar at linaro.org>

This is what i was asking you earlier: "Doesn't gpiochip_add_pin_range
have any users?" and you said NO and i didn't cross checked :(