gpio: of: don't warn if ignored GPIO flag matches the behavior

Some devicetrees specify the ACTIVE_LOW flag in the fixed regulator GPIO
handle. While this has always been ignored, it's consistent with the
behavior of the regulator binding in the absence of the
"enable-active-high" DT property. It doesn't make much sense to print a
user visible warning for a configuration which is consistent, so only
print the warning if the GPIO flag contradicts the behavior dictated by
by the enable-active-high property.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/gpio/gpiolib-of.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

pt., 18 paź 2019 o 12:05 Lucas Stach <l.stach@pengutronix.de> napisał(a):
>
> Some devicetrees specify the ACTIVE_LOW flag in the fixed regulator GPIO
> handle. While this has always been ignored, it's consistent with the
> behavior of the regulator binding in the absence of the
> "enable-active-high" DT property. It doesn't make much sense to print a
> user visible warning for a configuration which is consistent, so only
> print the warning if the GPIO flag contradicts the behavior dictated by
> by the enable-active-high property.
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>  drivers/gpio/gpiolib-of.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index 1eea2c6c2e1d..0b5383706b91 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -134,18 +134,20 @@ static void of_gpio_flags_quirks(struct device_node *np,
>              (!(strcmp(propname, "enable-gpio") &&
>                 strcmp(propname, "enable-gpios")) &&
>               of_device_is_compatible(np, "regulator-gpio")))) {
> +               bool active_low =
> +                       !of_property_read_bool(np, "enable-active-high");
>                 /*
>                  * The regulator GPIO handles are specified such that the
>                  * presence or absence of "enable-active-high" solely controls
>                  * the polarity of the GPIO line. Any phandle flags must
>                  * be actively ignored.
>                  */
> -               if (*flags & OF_GPIO_ACTIVE_LOW) {
> +               if ((*flags & OF_GPIO_ACTIVE_LOW) && !active_low) {
>                         pr_warn("%s GPIO handle specifies active low - ignored\n",
>                                 of_node_full_name(np));
>                         *flags &= ~OF_GPIO_ACTIVE_LOW;
>                 }
> -               if (!of_property_read_bool(np, "enable-active-high"))
> +               if (active_low)
>                         *flags |= OF_GPIO_ACTIVE_LOW;
>         }
>         /*
> --
> 2.20.1
>

This makes perfect sense, so applied right away.

Bart