[PATCH 0/4 v4] pin controller subsystem v4

Barry Song 21cnbao at gmail.com
Thu Aug 25 21:58:39 EDT 2011


2011/8/22 Linus Walleij <linus.walleij at linaro.org>:
> On Sun, Aug 21, 2011 at 4:42 PM, Barry Song <21cnbao at gmail.com> wrote:
>
>> it seems there is not an actual example that gpio requests pin from
>> pinctrl yet. i might give one on SiRFprimaII.
>
> No good example yet, no.
>
> The reason is that for the U300 that I use as guinea pig, the
> GPIO driver is tangled up in discussions about how to handle
> the special control mechanics like requesting muxing and
> biasing pins. Right now it seems easier to rewrite all that
> to use the new pinctrl subsystem rather than actually trying
> to work it into the GPIO subsystem first and refactor from
> there, and that needs quite a bit of upfront work...

Do you want the pinmux_request_gpio called by the gpiolib driver or by
every device driver who uses this gpio?
Do you think the following make sense in gpiolib driver?
static int xxx_gpio_request(struct gpio_chip *chip, unsigned offset)
{
        int ret = 0;

        ret = pinmux_request_gpio(chip->base + offset);
        if (ret)
                goto out;
        .....
out:
        return ret;
}


>
> Linus Walleij
>

Thanks
Barry



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